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The impact of the broad disjunction between Amazonia and the Atlantic Forest on biodiversity has been the theme of several discussions in recent decades. Here, we evaluate the effects of dependence on humid environments and the role of historical factors on the level, distribution and structuring of genetic variation in widely distributed Neotropical insects. For such, we test whether climatically stable zones (i.e. refuges) in both Amazonia and the Atlantic Forest concentrate higher genetic diversity in the social paper wasps Angiopolybia pallens and Synoeca surinama. We found that historical events have avoided the interchange of A. pallens between both rainforests at least since the Early Pliocene and that ancient colonization in north-western Amazonia and the Bahia refuge significantly predicts genetic diversity in populations of this species. Conversely, the split between the Atlantic Forest and remaining western populations of S. surinama is more recent (Plio-Pleistocene); this species has considerably lower genetic diversity than A. pallens and such diversity is mostly concentrated in Amazonia and in the cerrado biome (savanna) than in the Atlantic Forest. Finally, we propose that the occurrence of species that exhibit such distribution patterns should be taken into consideration when establishing areas for conservation. [ABSTRACT FROM AUTHOR]

Whether environmental conditions under exotic tree plantations abandoned in the Western Ghats of India can facilitate the natural regeneration of tropical montane forest (Shola forest) tree species is being debated. In many cases, the exotic tree plantations are being cleared to allow for the restoration of native ecosystems. In this paper, we examined whether exotic tree plantations have indeed a negative effect on the regeneration of Shola forest tree species. For this, we assessed the abundance, diversity, and composition of the regeneration of Shola forest tree species in plantations, each with different dominant tree species (Acacia mearnsii , Pinus sp. and Eucalyptus sp.). We tested the abundance of regenerating native tree species against the main plantation canopy species (plantation type) as well as other environmental factors (aspect, distance to nearest Shola forest, structural diversity, slope, elevation, presence of herbivores, and canopy closure). We found that the number of native tree species regenerating in all plantation types was at an acceptable level: 1960, 1773, and 462 individuals ha−1 for Acacia , Eucalyptus , and Pinus plantations, respectively. A rare fraction analysis showed that the highest number of Shola tree species were regenerating under Acacia mearnsii (25) followed by Eucalyptus (19) and Pinus (8) plantations. The density and diversity of regenerating Shola trees was greatest under Acacia plantations and northern aspects but declined with increasing elevation. The presence of herbivores also reduced the density and diversity of Shola tree regeneration. We concluded that the restoration of Shola forest in the Western Ghats is possible in existing stands of exotic tree species and this process can be accelerated with appropriate silvicultural methods. We additionally recommend that studies involving long-term exclosures can provide valuable insights into the effects of browsing on regeneration and species composition. [ABSTRACT FROM AUTHOR]

Land use changes from native vegetation to agriculture, livestock grazing, and urban development are among the main problems related to biodiversity loss worldwide. In this paper we evaluate how land use changes (eucalypt plantation and pasture) affect the richness and assemblage of wasps (Braconidae, Ichneumonidae, Pompilidae, and Vespidae), in comparison with nearby areas with native vegetation in the Cerrado. Specimens were collected at six points, with two Malaise traps at each location. The collections were performed monthly for 10 d, for 12 mo. A total of 773 hymenopterans of the selected groups were collected, representing 253 species or morphospecies. Richness of the families Ichneumonidae and Pompilidae between the areas did not present significant differences. For the families Braconidae and Vespidae, the richness was greater in the eucalypt plantation and pasture areas compared to the native area. Species composition in the native habitat was different from either of the managed habitats in the studied environment. Furthermore, the composition of wasps in native areas varied less throughout the sampling campaigns when compared with the pasture and eucalyptus sites. In native areas, 85 exclusive morphospecies were found. Thus, changes in land use may cause changes in the composition of wasp species, since areas with native vegetation presented more heterogeneous and stable environments than the other land uses. The maintenance of native areas, even if close to planted forest and/or pasture areas, could be the best way to combine forest productivity with biodiversity conservation. [ABSTRACT FROM AUTHOR]

A primary prerequisite for the preservation of global diversity is often assumed to be a high level of naturalness. This paper reports a synthesis of naturalness definitions, distinctions between the concepts of naturalness and of hemeroby and an analysis of different naturalness assessment approaches. Naturalness may be commonly defined as ‘the similarity of a current ecosystem state to its natural state’. Hemeroby, a concept related to human impacts, is often associated with naturalness but, in principle, the two concepts are not inversely related. The hemeroby concept defines narrow assessment classes for greater hemeroby, whereas the naturalness concept defines narrow assessment classes for great naturalness. The rapidly increasing number of forest naturalness papers relies on the following main indicators in decreasing order of use: tree species, forest structure, fauna, ground vegetation and deadwood. A review of the literature on forest naturalness suggests four main reasons for the lack of a widely accepted approach for assessing naturalness: (1) the lack of a commonly accepted reference concept, (2) an incomplete list of essential naturalness traits, (3) unknown linkages between some naturalness traits and biodiversity and (4) the lack of an assessment approach that can be adapted for use at both regional and large scales. Following review of the literature on forest naturalness, a seven-level framework is presented to guide development of naturalness assessment approaches as a component of forest biodiversity monitoring and conservation management. [ABSTRACT FROM AUTHOR]

Ecosystem services (ES) are the benefits that people receive from ecosystems. Understanding the impact of forest management on their supply can inform policy and practice for meeting societal demand. The objectives of this paper are to identify and review the effect of management intensity on priority ES supply and identify synergies and trade-offs among ES of different management approaches. We review seven priority ES identified from UK land and forestry strategy and policy documents: timber/biomass production, carbon storage, biodiversity, health and recreation, water supply and quality and flood protection. We present a synthesis of the impact of management on relative ES supply. It shows that low intensity management is unsuitable for high biomass production, yet provides high or moderately high levels of other services. Higher intensity management impacts negatively on biodiversity, health and recreation and water supply services. Combined objective forestry provides high or moderately high levels for all services except biomass. We recommend that a diversity of management approaches is needed to maintain multiple ecosystem service provision. The ES framework offers opportunities to forest management by revealing areas of conflict or co-production and potential trade-offs that may arise from adjusting management intensity. [ABSTRACT FROM AUTHOR]

Stem taper equations are crucial for forest management allowing to reliably estimate merchantable wood volume. Their main benefit is the ability to predict stem diameters at a certain height of the stem. Ukraine has recently adopted European Union standards for round wood classification, which prompted the necessity to model stem taper and updates all reference data to conform with the new standards. This study is a systematic attempt to develop a set of taper equations for the most common forest tree species in the Polissia and Forest steppe of Ukraine. For this purpose, we used a data set of 1994 sample trees representing eight tree species collected on 238 sample plots. The Kozak A. (2004, My last words on taper equations. For. Chron.   80 , 507–515) model was chosen to fit the taper equations. To characterize the variability in stem shape among tree species, mixed-effect models were calibrated for this equation. In this model, random-effect parameters were selected based on their coefficients of variation through a bootstrapping process. This is a novel feature we suggest for the process of calibrating taper models. The Kozak A. (2004, My last words on taper equations. For. Chron.   80 , 507–515) equation showed a good performance in predicting diameters outside bark and estimating the total stem volume. Our mixed-effect modelling approach accurately characterizes the variation in stem form for different tree species based on adequately chosen random-effect parameters. The stem volumes derived from the developed taper models were compared with existing volume equations outputs (divergence up to 0.5 per cent). A deviation up to 5 per cent was found between the values of fitted and observed cylindrical form factors for the studied tree species. We expect that our taper equations will complement the future steps towards the development of reliable merchantable volume distribution models for the main tree species in the forests of flat land Ukraine, thus, contributing to transparency, reliability and sustainability of forest management and markets in Europe. [ABSTRACT FROM AUTHOR]

Tree perception is an essential building block toward autonomous forestry operations. Current developments generally consider input data from lidar sensors to solve forest navigation, tree detection and diameter estimation problems, whereas cameras paired with deep learning algorithms usually address species classification or forest anomaly detection. In either of these cases, data unavailability and forest diversity restrain deep learning developments for autonomous systems. Therefore, we propose two densely annotated image datasets—43 k synthetic, 100 real—for bounding box, segmentation mask and keypoint detections to assess the potential of vision-based methods. Deep neural network models trained on our datasets achieve a precision of 90.4 % for tree detection, 87.2 % for tree segmentation and centimeter accurate keypoint estimations. We measure our models' generalizability when testing it on other forest datasets, and their scalability with different dataset sizes and architectural improvements. Overall, the experimental results offer promising avenues toward autonomous tree felling operations and other applied forestry problems. The datasets and pre-trained models in this article are publicly available on GitHub (https://github.com/norlab-ulaval/PercepTreeV1). [ABSTRACT FROM AUTHOR]

Background and Aims The Atlantic Forest biodiversity hotspot is a complex mosaic of habitat types. However, the diversity of the rain forest at the core of this complex has received far more attention than that of its marginal habitats, such as cloud forest, semi-deciduous forest or restinga. Here, we investigate broad-scale angiosperm tree diversity patterns along elevation gradients in the south-east Atlantic Forest and test if the diversity of marginal habitats is shaped from the neighbouring rain forest, as commonly thought. Methods We calculated phylogenetic indices that capture basal [mean pairwise phylogenetic distance (MPD)] and terminal [mean nearest taxon distance (MNTD)] phylogenetic variation, phylogenetic endemism (PE) and taxonomic and phylogenetic beta diversity (BD and PBD) for 2074 angiosperm tree species distributed in 108 circular sites of 10 km diameter across four habitat types i.e. rain forest, cloud forest, semi-deciduous forest and coastal vegetation known as restinga. We then related these metrics to elevation and environmental variables. Key Results Communities in wetter and colder forests show basal phylogenetic overdispersion and short phylogenetic distances towards the tips, respectively. In contrast, communities associated with water deficit and salinity show basal phylogenetic clustering and no phylogenetic structure toward the tips. Unexpectedly, rain forest shows low PE given its species richness, whereas cloud and semi-deciduous forests show unusually high PE. The BD and PBD between most habitat types are driven by the turnover of species and lineages, except for restinga. Conclusions Our results contradict the idea that all marginal habitat types of the Atlantic Forest are sub-sets of the rain forest. We show that marginal habitat types have different evolutionary histories and may act as 'equilibrium zones for biodiversity' in the Atlantic Forest, generating new species or conserving others. Overall, our results add evolutionary insights that reinforce the urgency of encompassing all habitat types in the Atlantic Forest concept. [ABSTRACT FROM AUTHOR]

The relationship between biodiversity and ecosystem functioning has become a central issue in any forest ecosystem. However, there are few studies on the interaction of environmental factors based on the history of subtropical forest disturbance. In this study, we intended to disentangle the relationship between different aspects of biodiversity and biomass or biomass change when considering the environmental factors of 34 subtropical forest plots in Zhejiang Province, eastern China. We used linear models to analyze the effects of taxonomic, functional and phylogenetic diversity at the plot level of tree biomass and its growth with or without environmental factors. Taxonomic diversity and functional diversity, rather than phylogenetic diversity, showed significant correlations with biomass and biomass growth. We further found that there was a positive linear relationship between biomass or biomass growth and mean annual temperature and altitude. In addition, the relationship between biomass growth and functional diversity was significantly stronger than the relationship between biomass growth and phylogenetic diversity or taxonomic diversity when environmental factors and stand developmental stages were considered. Our results suggested that the relationship between biodiversity and ecosystem functioning is dependent upon the selection of diversity index and environmental conditions. [ABSTRACT FROM AUTHOR]

Caryota obtusa of Arecaceae is a fascinating palm tree native to southwestern China, India, Myanmar, Thailand, Laos and Vietnam. It is an economically important and threatened species and appears as a canopy dominant in some karst areas in Yunnan. We aim to clarify the forest structure, species diversity, population status and regeneration dynamics of C. obtusa in the karst forest ecosystem of Yunnan, China. We established 56 vegetation plots dominated by C. obtusa in 10 counties of southern Yunnan. Based on the plot data, we analyzed the community stratification, floristic composition and C. obtusa 's population structure. We used questionnaires to interview local people and recorded the human activity history in C. obtusa -dominated forests. Caryota obtusa palm forests were distributed on limestone mountain slopes and gullies. There were seven forest community types. The stratification of each community included arborous layer, shrub layer and understory. The communities had rich species composition. For all the plots as a whole of each community type, Shannon–Wiener diversity index of either woody or herbaceous species ranged from 2.1 to 3.8. The diameter at breast height (DBH)-class frequency distribution of C. obtusa was a multimodal type. The regeneration was sporadic and dependent on intermediate natural disturbances. In the current population structure, a number of C. obtusa trees with small DBHs consisted mainly of the forest communities with no or a slight degree of human disturbances. Intensive human activities terribly hindered recruitment of C. obtuse , followed by the medium intensity of human activities. [ABSTRACT FROM AUTHOR]

The analyzation of the dynamics of biodiversity, carbon storage and environmental factors of coniferous forest in Loudi, Hunan Province is meaningful, and the determination of the aboveground and underground carbon storage, plant diversity and environmental factors of multiple plant communities in Loudi, Hunan Province among different succession stage is of great significance to effectively clarify the distribution of plant diversity and carbon storage in coniferous forests along the succession gradient, to clarify the influence of environmental factors on carbon storage, and to quantify the relationship between carbon storage and plant diversity. This article selected the natural growth of subalpine coniferous forest in Loudi, Hunan Province from 5 to 60 years as the research objective and compared the species richness (S), plant diversity (S) and other information. The results showed that the carbon pools of aboveground and underground ecosystems of several plant communities are significantly different during vegetation restoration, and there is a functional relationship between plant diversity and carbon storage. The aboveground carbon content increased several times, and the soil organic carbon (SOC) content increased from the herbaceous community type to the mixed forest type, constituting the main carbon pool of the system (63–89%) and then decreased. The average carbon storage of the whole ecosystem was between 105 and 730 Mg C ha−1. In addition, it was also found that root biomass and litter C/N ratio had significant effects on SOC. Path analysis also showed that the C/N ratio of litter was mainly regulated by the changes of microbial population and soil invertase activity. The research of this project is of positive significance to deepen the understanding of coniferous forest biodiversity and corresponding conservation measures. [ABSTRACT FROM AUTHOR]

Woody debris left after timber harvest may be used to produce bioenergy. This will help reduce reliance on nonrenewable fossil fuels. There are ecological impacts to the use of this woody material as many species use coarse woody debris for food and shelter. An understanding of how the removal of woody biomass after forest harvest changes the functional diversity of forest communities is needed to make sustainable management decisions. Many longhorned beetles (Coleoptera: Cerambycidae) provide ecosystem services by reducing woody debris in forests and pollinating flowering plants including trees. I used a taxonomically and functionally diverse community of longhorned beetles to examine changes to functional diversity following different levels of biomass removal in a secondary forest in south-central Indiana, USA.The functional diversity was measured prior to forest harvest and biomass removal and for 2 yr after treatment. I predicted that the abundance and functional group richness of the longhorned beetles would correlate positively with the volume of woody biomass left on the site, and that the community would show resilience by returning to the functional portfolio that was in place in the pre-harvest communities and occurred in the control. The abundance and functional group richness increased with more woody debris left on site.There was much variance in the trajectory of the community following harvest, with no clear trend toward pre-harvest functional portfolio that would indicate resilience. A 3-yr study is likely not long enough to capture this resilience, especially on sensitive sites. [ABSTRACT FROM AUTHOR]

A 6-year time-series study in the Western Everglades region of Florida, United States examined the influence of woody debris from two tree species on invertebrate richness, abundance, and diversity, as well as tree debris mass loss, fragmentation, and residence time. Samples of decomposing fine woody debris and coarse woody debris (CWD) from non-native Melaleuca quinquenervia (Cav.) Blake and native Pinus elliottii Englem trees were removed from a field site every six months and processed to capture data on biotic and abiotic variables. Invertebrates found within debris were identified to family. A total of 61,985 individual invertebrates from three classes, 17 orders, and 95 families were identified from all debris. Although both tree species supported similar richness and diversity of invertebrates, abundance was greater in P. elliottii CWD compared with M. quinquenervia. Mass loss and fragmentation of debris were more rapid in M. quinquenervia fine woody debris with no differences between species for CWD. Although M. quinquenervia CWD supported fewer invertebrates than P. elliottii, overall the exotic tree provided a similar resource during the decomposition phase as the native P. elliottii suggesting that, unlike when it is alive, its decomposing presence had a minimal impact on invertebrate food webs. Land managers should consider specific intervals between herbicide applications and controlled burns to decrease the magnitude of fires in areas where a significant portion of the fuel load consists of dead M. quinquenervia, knowing that the decomposing trees are providing significant resources for invertebrate communities in the meantime. [ABSTRACT FROM AUTHOR]

Differences in plant shade tolerance constitute a major mechanism driving the succession of forest communities in subtropical forests. However, the indirect effects of differences in light requirements on the growth of mid- and late-successional tree species are unclear, and this potential growth effect has not been explained at the transcriptome level. Here, a typical mid-successional dominant tree species, Schima superba Gardn. et Champ , and a typical late-successional dominant tree species, Cryptocarya concinna Hance were used as materials and planted under 100% full light (FL) and 30% FL (low light, LL) to explore the responses of tree species in different successional stages of subtropical forests to different light environments. Transcriptome sequencing was used to analyze the expression changes in genes related to growth and photoprotection under different light environments. The young leaves of S. superba accumulated more malondialdehyde (MDA) and superoxide radicals (⁠|${\mathrm{O}}_2^{{{}^{\bullet}}^{-}}$|⁠) under LL. A lower hormone content (auxin, cytokinin, gibberellin) in the young leaves, a weaker photosynthetic capacity in the mature leaves and significant downregulation of related gene expression were also found under LL, which resulted in the total biomass of S. superba under LL being lower than that under FL. The young leaves of C. concinna had less MDA and |${\mathrm{O}}_2^{{{}^{\bullet}}^{-}}$|⁠ , and a higher hormone contents under LL than those under FL. There was no significant difference in photosynthetic capacity between mature leaves in contrasting light environments. Although the biomass of C. concinna under LL was less than that under FL, the height of C. concinna under LL was higher than that under FL, indicating that C. concinna could grow well under the two light environments. Our results describing the acclimatization of light at the physiological, molecular and transcriptome levels are important for a complete understanding of successional mechanisms. [ABSTRACT FROM AUTHOR]

Deciduous Beech (Fagus spp.) forests have a highly disjunct distribution in the Northern Hemisphere, with greatest diversity in eastern Asia. Although Fagus supports a rich phytophagous insect fauna, the diversity, composition, and host specialization of insects associated with these trees in Asia are less well known compared with Europe and North America. For instance, two species of Catocala moths, both considered endemic to Japan, were previously known as the only beech-feeding specialists of this genus. However, two Catocala species were recently discovered from Taiwan during a survey of phytophagous insects on Taiwan Beech Fagus hayatae , a threatened plant. Identification of these two species of moths was determined by mtDNA (COI barcodes), adult morphology, including wing pattern and genitalia, and biology. Based on these multiple sources of evidence, we conclude that one species represents an undescribed species and the other a new subspecies of a species previously known only from mainland China. The taxonomic treatments in the present work include Catocala seiohbo sanctocula Hsu & Huang, subsp. nov. , C. nimbosa Hsu & Wang, sp. nov. and C. nubila ohshimai , stat. nov. In Taiwan, Catocala spp. occur mainly in large, undisturbed patches of Taiwan Beech forest and are codependent on F. hayatae. Thus, they are not only considered to be at risk of co-extinction, but may serve as potential indicator species to monitor the extent and health of this threatened ecological community. [ABSTRACT FROM AUTHOR]

National forest inventories, in which trees are often mapped within the plots, provide a tool for the quantification of large-scale forest structure since they cover all forest areas. Many National Forest Inventories follow a nested design in order to reduce the sampling effort for smaller trees. We propose and test a methodology that allows the spatial pattern of trees, species mingling and size differentiation to be characterized using the nearest neighbour indices and second-order moment functions from nested plot data. The nearest neighbour indices and second-order moment functions for the actual distribution are compared with simulations of the appropriate null model: spatial randomness for spatial pattern characterization or spatial independence for species mingling and size differentiation. The proposed method consists of constraining the null model to fit the nested plot design. For the purposes of the study, we simulated 120 plots and used 26 real plots located in pure and mixed stands in Central Spain, for which a complete census with detailed information about trees was available. The nested design used in the Spanish National Forest Inventory (SNFI) plots was simulated to test the performance, taking the complete census as reference. Despite of the limited accuracy for some structural measures, the proposed method based on nested design data performed better for most of the nearest neighbour indices and second-order moment functions than the strategy currently used in the SNFI for structure assessment in a subsample of SNFI plots, consisting of mapping the 20 trees closest to the plot centre. Nearest neighbour indices provided greater accuracy for species mingling assessment than second-order moment functions, whereas the opposite occurred when describing spatial pattern and size differentiation. The methodology proposed provides the first insight into the characterization of forest structure in nested designs although more evaluations are required for different forest types. [ABSTRACT FROM AUTHOR]

Over the last four decades, forest management goals have transitioned to multiuse objectives, begging the question of their impact on wildlife habitat. Using USDA Forest Service Forest Inventory and Analysis data and the WHINGS (Wildlife Habitat Indicator for Native Genera and Species) model, the trends in wildlife habitat were quantified from 1977 to 2018 across Minnesota. Statewide, 35.5% of species experienced significant improvement in habitat, 29% significant reductions, and 35.5% nonsignificant change. The extent of habitat (acreage) increased for 100% of species, but the quality declined for 63% of species. Results were explained by the reduction in acreage of larger size classes of the aspen, balsam, and birch forest type and increases in smaller, younger forest area. Specifically, forest management that converted aspen stands to other forest types benefited certain wildlife species over others. Future forest management should consider the balance between the habitat requirements of the diverse native species in Minnesota. Study Implications Trends in forest wildlife habitat over the last four decades across Minnesota highlight that forest management often favors one species at the expense of another. Statewide, wildlife species with preferences for larger, older aspen experienced diminished habitat, whereas habitat for species preferring younger forest types or older nonaspen types increased. Regionally, the forested ecoregions in Minnesota (northeast) generally saw reduced habitat, whereas the prairie/agricultural regions (south and northwest) saw the largest increases. Through this and further applications, forest and wildlife managers can rapidly assess the habitat implications of proposed management, whether for environmental review, forest planning, or harvest scheduling. [ABSTRACT FROM AUTHOR]

Aims Phylogenetic diversity metrics can discern the relative contributions of ecological and evolutionary processes associated with the assembly of plant communities. However, the magnitude of the potential variation associated with phylogenetic methodologies, and its effect on estimates of phylogenetic diversity, remains poorly understood. Here, we assess how sources of variation associated with estimates of phylogenetic diversity can potentially affect our understanding of plant community structure for a series of temperate forest plots in China. Methods In total, 20 forest plots, comprising of 274 woody species and 581 herbaceous species, were surveyed and sampled along an elevational gradient of 2800 m on Taibai Mountain, China. We used multi-model inference to search for the most parsimonious relationship between estimates of phylogenetic diversity and each of four predictors (i.e. type of phylogenetic reconstruction method, phylogenetic diversity metric, woody or herbaceous growth form and elevation), and their pairwise interactions. Important Findings There was no significant difference in patterns of phylogenetic diversity when using synthesis-based vs. molecular-based phylogenetic methods. Results showed that elevation, the type of phylogenetic diversity metric, growth form and their interactions, accounted for >44% of the variance in our estimates of phylogenetic diversity. In general, phylogenetic diversity decreased with increasing elevation; however, the trend was weaker for herbaceous plants than for woody plants. Moreover, the three phylogenetic diversity metrics showed consistent patterns (i.e. clustered) across the elevational gradient for woody plants. For herbaceous plants, the mean pairwise distance showed a random distribution over the gradient. These results suggest that a better understanding of temperate forest community structure can be obtained when estimates of phylogenetic diversity include methodological and environmental sources of variation. [ABSTRACT FROM AUTHOR]

Thinning is a necessary silvicultural activity for restoring the long-term sustainability of pine forests in much of the southwestern United States. In northern Arizona, a landscape-scale restoration effort, called the Four Forest Restoration Initiative, has been implemented to recover the long-term sustainability of 2.4 million acres on four national forests. Cost-effective and efficient thinning methods are needed due to the scale of the project to help improve habitat, conserve biodiversity, protect old growth, reduce risk of severe wildfire, and restore natural forest structure and function. Mechanical cutting using a feller-buncher is the primary method of thinning in these forests due to the extreme high number of small-diameter ponderosa pine trees. A feller-buncher places harvested trees into small piles known as "bunches." In this review, we highlight advantages and disadvantages of bunching tree materials in restoration programs and review published studies on transpirational drying of bunches of various tree species in different forest habitats across the United States, including ponderosa pine in Arizona. Studies show that transpirational drying of trees in bunches can be an effective method to allow for wood drying, but this process can be affected by abiotic factors associated with seasonal climate and stand characteristics. Study Implications The Four Forest Restoration Initiative makes up the largest landscape-level collaborative project in the history of the USDA Forest Service with more than 2.4 million acres of forest habitat. Thinning is a necessary silvicultural activity for restoring the long-term sustainability of these forests in northern Arizona. Because of the extremely high number (i.e. average of 720 trees per acre) of small-diameter ponderosa pine (Pinus ponderosa) trees, mechanical cutting is more cost effective than individual saw cutting, which is why a feller-buncher machine is the primary thinning tool. During feller-buncher thinning, small piles of trees known as "bunches" are created. Bunching trees can allow for wood drying in the field that translates into lower operational costs because drier trees are lighter in weight, which reduces transportation costs. In northern Arizona, a 60-day time frame is allotted for transpirational drying before tree materials must be removed from the forest. However, because the drying process through bunching is affected by abiotic conditions, there may be a need to adjust this time frame to account for seasonal weather patterns. For example, during spring, when weather in northern Arizona is hot and dry, less time might be necessary for tree bunches to lose enough moisture while still rendering the thinning operation profitable and simultaneously avoiding bark beetle proliferation given that their life cycle consists of about 40 days. Furthermore, bunching studies should be developed to look at individual tree species in their respective locations and to investigate the effects of the presence, partial presence, or absence of branches and bark on trees within bunches. Studies should also be conducted to look at the effects of bunches on insect communities, particularly those that can cause extensive tree mortality. [ABSTRACT FROM AUTHOR]

Aims Assessing the role of a dominant native bamboo species on tree species diversity and structure in the medium term. Methods Over a 7-year period, we studied the natural regeneration of two dominant forest types in Southern Brazil (Araucaria Forest or AF; Bamboo Forest or BF) after a bamboo (Merostachys skvortzovii Send.) die-off between 2004 and 2006. The study was carried out in the Embrapa Research Station in Caçador, Santa Catarina State, Brazil. Important Findings The die-off provided ideal conditions for the establishment of several species and it kickstarted forest succession dynamics, which in turn affected regeneration diversity. Tree species richness was relatively stable with a transitory increase between 2007 and 2014 in both AF and BF. However, species richness rose in BF because of a relative increase in abundance of some species (especially late and secondary species) while a plunge in some pioneer species drove an increase in diversity. Overall, we found that BF has a lower diversity of recruits and that density declined over time, while AF is more diverse, with a more stable density. In BF, the bamboo die-off created optimal conditions for initial regeneration development (mainly fast-growing pioneer trees), which quickly transited to higher size classes. Yet, after this initial stage of pioneer recruitment, the number of recruits dropped followed by a virtual absence of growth regardless of the species group as a result of a quick bamboo reestablishment. As bamboo recreated a dense understory it reduced species diversity to original levels, suggesting a self-maintaining cycle that halts forest succession. On the other hand, the bamboo die-off had little impact on AF where a slow recruitment process typical of old-growth forests was observed. The results indicate that the die-off event had a temporary effect on species diversity i.e. restricted to forests where bamboos are dominant in a similar process described in other southern South American forests. As the first study to observe the medium-term forest dynamics related to bamboo die-off, we can conclude that when being dominant, native bamboos can hinder forest regeneration, maintaining lower levels of diversity and arresting forest succession that lasts well beyond the short-term, post-die-off effects. Many forest fragments in the region are dominated by bamboos, thus their potential for conservation is at risk and requires appropriate management. [ABSTRACT FROM AUTHOR]

Highlights from the article: Spatial variables in pRDA before performing MSO analysis. For MSO(Y~E|S) (denoting MSO analysis for pRDA of MSO(Y~E|S) and MSO(Y~S|E) (Fig. 1a and b), the residual Found in both MSO(Y~E|S) and MSO(Y~S|E) analyses, indi-.

Background: Advancements in portable scientific instruments provide promising avenues to expedite field work in order to understand the diverse array of organisms that inhabit our planet. Here, we tested the feasibility for in situ molecular analyses of endemic fauna using a portable laboratory fitting within a single backpack in one of the world's most imperiled biodiversity hotspots, the Ecuadorian Choc'o rainforest. We used portable equipment, including the MinION nanopore sequencer (Oxford Nanopore Technologies) and the miniPCR (miniPCR), to perform DNA extraction, polymerase chain reaction amplification, and real-time DNA barcoding of reptile specimens in the field. Findings: We demonstrate that nanopore sequencing can be implemented in a remote tropical forest to quickly and accurately identify species using DNA barcoding, as we generated consensus sequences for species resolution with an accuracy of >99% in less than 24 hours after collecting specimens. The flexibility of our mobile laboratory further allowed us to generate sequence information at the Universidad Tecnol 'ogica Indoam' erica in Quito for rare, endangered, and undescribed species. This includes the recently rediscovered Jambato toad, which was thought to be extinct for 28 years. Sequences generated on the MinION required as few as 30 reads to achieve high accuracy relative to Sanger sequencing, and with further multiplexing of samples, nanopore sequencing can become a cost-effective approach for rapid and portable DNA barcoding. Conclusions: Overall, we establish how mobile laboratories and nanopore sequencing can help to accelerate species identification in remote areas to aid in conservation efforts and be applied to research facilities in developing countries. This opens up possibilities for biodiversity studies by promoting local research capacity building, teaching nonspecialists and students about the environment, tackling wildlife crime, and promoting conservation via research-focused ecotourism. [ABSTRACT FROM AUTHOR]

Aims It is known that taxonomic diversity can be predicted by the spatial configuration of the habitat, in particular by its area and degree of isolation. However, taxonomic diversity is a poor predictor of ecosystem functioning. While functional diversity is strongly linked to the functionality and stability of ecosystems, little is known about how changes in the spatial configuration of the habitat affect functional diversity. In this study, we evaluated whether the spatial configuration of forest patches predicts the functional diversity of plants in a fragmented forest. Methods Five functional leaf traits (leaf dry matter content, leaf punch force, specific leaf area, leaf size and leaf thickness) were measured for 23 dominant plant species in 20 forest patches in a naturally fragmented forest on the yucatan Peninsula. Abundance-weighted multivariate and individual trait metrics of functional diversity were calculated and correlated with size, degree of isolation and the shape of forest patches. Important Findings Patch shape was negatively correlated with multivariate and individual trait (leaf dry matter content and leaf size) metrics of functional diversity. Patch isolation measures were also negatively correlated with individual trait (leaf dry matter content, leaf punch force and leaf size) metrics of functional diversity. In other words, greater patch shape irregularity and isolation degree impoverish plant functional variability. This is the first report of the negative effects of patch shape irregularity and isolation on the functional diversity of plant communities in a forest that has been fragmented for a long time. [ABSTRACT FROM AUTHOR]

Background: Handroanthus impetiginosus (Mart. ex DC.) Mattos is a keystone Neotropical hardwood tree widely distributed in seasonally dry tropical forests of South and Mesoamerica. Regarded as the "new mahogany," it is the second most expensive timber, the most logged species in Brazil, and currently under significant illegal trading pressure. The plant produces large amounts of quinoids, specialized metabolites with documented antitumorous and antibiotic effects. The development of genomic resources is needed to better understand and conserve the diversity of the species, to empower forensic identification of the origin of timber, and to identify genes for important metabolic compounds. Findings: The genome assembly covers 503.7 Mb (N50 = 81 316 bp), 90.4% of the 557-Mbp genome, with 13 206 scaffolds. A repeat database with 1508 sequences was developed, allowing masking of ~31% of the assembly. Depth of coverage indicated that consensus determination adequately removed haplotypes assembled separately due to the extensive heterozygosity of the species. Automatic gene prediction provided 31 688 structures and 35 479 messenger RNA transcripts, while external evidence supported a well-curated set of 28 603 high-confidence models (90% of total). Finally, we used the genomic sequence and the comprehensive gene content annotation to identify genes related to the production of specialized metabolites. Conclusions: This genome assembly is the first well-curated resource for a Neotropical forest tree and the first one for a member of the Bignoniaceae family, opening exceptional opportunities to empower molecular, phytochemical, and breeding studies. This work should inspire the development of similar genomic resources for the largely neglected forest trees of the mega-diverse tropical biomes. [ABSTRACT FROM AUTHOR]

Aims: Litterfall, as an important link between aboveground and belowground processes, plays a key role in forest ecosystems. Here, we test for effects of tree species richness on litter production and litter quality in subtropical forest. The study further encompasses a factorial gradient of secondary succession that resulted from human exploitation. Given that a large percentage of subtropical forests are in secondary successional stages, understanding the role of biodiversity on forest re-growth after disturbance appears critical. Methods: From January 2009 to December 2014, we monitored forest litterfall in 27 Comparative Study Plots that spanned a gradient of tree species richness (3-20 species) and secondary successional ages (∼20 to 120 years) in Gutianshan Natural Nature Reserve, Zhejiang Province, China. The experiment is part of the biodiversity-ecosystem functioning research platform 'BEF-China'. Tree litterfall was collected in monthly intervals using litter traps. Samples were separated into leaf and non-leaf components. Leaf litter was further sorted into dominant and other species. Community level monthly leaf litter C and N contents were analysed through a full year. General linear mixed-effects models were applied to test for effects of tree species richness and successional age on litter quantity and leaf litter C/N. Important Findings: Litterfall increased with species richness among and within successional age and this effect was consistent across years. Successionally older stands had higher litterfall and this effect was related to increased tree species richness. However, species richness did not change the intra- and inter-annual temporal stability of litterfall. Increasing tree species richness increased leaf litter quality (decreased C/N), while successional age had no effect. Our study indicates that more diverse forest stands produce more leaf litter and that this litter has higher N concentrations, which could promote forest growth through accelerated nutrient re-cycling. [ABSTRACT FROM AUTHOR]

Aims: Litter decomposition is a fundamental process within ecosystem functioning and it is largely dependent on the biodiversity of ecosystems. We explored the effects of species diversity and genetic diversity of litter on the litter decomposition rate. Methods: We used laboratory microcosms to determine whether species diversity and genetic diversity and their interaction affect leaf litter decomposition. We set up 8 treatments containing 1, 2, 4 diversity levels of four broad-leaf species (Alniphyllum fortunei, Idesia polycarpa, Cinnamomum camphora and Daphniphyllum oldhamii) both in species and genetic sense. Totally 246 microcosms containing same amount of soil and litter of prescribed diversity treatment were stored in the dark at 25°C for 12 weeks. Important Findings The effect of litter species diversity on litter decomposition was largely dependent on species composition of the litter mixture in terms of species identity. Overall, the decomposition rate increased linearly with the richness of seed family when the species identity was disregarded. However, no interactive effect of species diversity and genetic diversity on mass loss was detected. The litter decomposition rate was found to be unrelated to the initial carbon (C), whereas it was negatively correlated with the initial total nitrogen (N) and N:P ratio. However, the regression curves of the litter decomposition rate against the total P and C:N ratio displayed quadratic parabolas opening upward and downward, respectively. This study demonstrated how species and/or genetic diversity and the stoichiometry of litter per se affect litter decomposition. Further studies should be performed in the long term to ascertain how such effects operate and how they change during the decomposition process, particularly in response to varying composition and diversity of standing plants in the environments. [ABSTRACT FROM AUTHOR]

Aims The aim of our research was to understand small-scale effects of topography and soil fertility on tree growth in a forest biodiversity and ecosystem functioning (BEF) experiment in subtropical SE China. Methods: Geomorphometric terrain analyses were carried out at a spatial resolution of 5 x 5 m. Soil samples of different depth increments and data on tree height were collected from a total of 566 plots (667 m2 each). The soils were analyzed for carbon (soil organic carbon [SOC]), nitrogen, acidity, cation exchange capacity (CEC), exchangeable cations and base saturation as soil fertility attributes. All plots were classified into geomorphological units. Analyses of variance and linear regressions were applied to all terrain, soil fertility and tree growth attributes. Important Findings: In general, young and shallow soils and relatively small differences in stable soil properties suggest that soil erosion has truncated the soils to a large extent over the whole area of the experiment. This explains the concurrently increasing CEC and SOC stocks downslope, in hollows and in valleys. However, colluvial, carbonrich sediments are missing widely due to the convexity of the footslopes caused by uplift and removal of eroded sediments by adjacent waterways. The results showed that soil fertility is mainly influenced by topography. Monte-Carlo flow accumulation (MCCA), curvature, slope and aspect significantly affected soil fertility. Furthermore, soil fertility was affected by the different geomorphological positions on the experimental sites with ridge and spur positions showing lower exchangeable base cation contents, especially potassium (K), due to leaching. This geomorphological effect of soil fertility is most pronounced in the topsoil and decreases when considering the subsoil down to 50 cm depth. Few soil fertility attributes affect tree height after 1-2 years of growth, among which C stocks proved to be most important while pHKCl and CEC only played minor roles. Nevertheless, soil acidity and a high proportion of Al on the exchange complex affected tree height even after only 1-2 years growth. Hence, our study showed that forest nutrition is coupled to a recycling of litter nutrients and does not only depend on subsequent supply of nutrients from the mineral soil. Besides soil fertility, topography affected tree height. We found that especially MCCA as indicator of water availability affected tree growth at small-scale, as well as aspect. Overall, our synthesis on the interrelation between fertility, topography and tree growth in a subtropical forest ecosystem in SE China showed that topographic heterogeneity lead to ecological gradients across geomorphological positions. In this respect, small-scale soil-plant interactions in a young forest can serve as a driver for the future development of vegetation and biodiversity control on soil fertility. In addition, it shows that terrain attributes should be accounted for in ecological research. [ABSTRACT FROM AUTHOR]

Aims: Although the net biodiversity effect (NE) can be statistically partitioned into complementarity and selection effects (CE and SE), there are different underlying mechanisms that can cause a certain partitioning. Our objective was to assess the role of resource partitioning and species interactions as two important mechanisms that can bring about CEs by interspecific and intraspecific trait variation. Methods: We measured tree height of 2493 living individuals in 57 plots and specific root length (SRL) on first-order roots of 368 of these individuals across different species richness levels (1, 2, 4, 8 species) in a large-scale forest biodiversity and ecosystem functioning experiment in subtropical China (BEF-China) established in 2009. We describe the effects of resource partitioning between species by a fixed component of interspecific functional diversity (RaoQ) and further effects of species interactions by variable components of interspecific and intraspecific functional diversity (community weighted trait similarity and trait dissimilarity, CWS and CWD). Finally, we examined the relationships between biodiversity effects on stand-level tree height and functional diversity (RaoQ, CWS and CWD) in SRL using linear regression and assessed the relative importance of these three components of functional diversity in explaining the diversity effects. Important Findings: Our results show that species richness significantly affected SRL in five and tree height in ten out of 16 species. A positive NE was generally brought about by a positive CE on stand-level tree height and related to high values of RaoQ and CWS in SRL. A positive CE was related to high values of all three components of root functional diversity (RaoQ, CWS and CWD). Our study suggests that both resource partitioning and species interactions are the underlying mechanisms of biodiversity effects on stand-level tree growth in subtropical forest. [ABSTRACT FROM AUTHOR]

Aims: Growth rates of plants are driven by factors that influence the amount of resources captured and the efficiency of resource use. In trees, the amount of light captured and the efficiency of light use strongly depends on crown characteristics and leaf traits. Although theory predicts that both crown and leaf traits affect tree growth, few studies have yet to integrate these two types of traits to explain species-specific growth rates. Using 37 broad-leaved tree species of subtropical forests in SE China, we investigated how interspecific differences in wood volume growth rates were affected by crown and leaf traits. We tested the hypotheses that (i) larger crown dimensions promote growth rates, (ii) species-specific growth rates are positively related to leaf stomatal conductance, leaf water potential and leaf chemical components and negatively related to leaf C/N and leaf toughness and (iii) the two sets of traits better explain growth rates in combination than either alone. Methods: Our study was conducted in a large-scale forest Biodiversity and Ecosystem Functioning experiment in China (BEF-China), located in a mountainous region in Jiangxi Province. We related 17 functional traits (two crown dimension and three crown structure traits; six physiological and six morphological leaf traits) to the mean annual growth rate of wood volume of young trees of the studied species. Interrelationships between crown and leaf traits were analyzed using principal component analysis. Simple linear regression analysis was used to test the effect of each trait separately. We used multiple regression analysis to establish the relationship of growth rate to each set of traits (crown traits, physiological and morphological leaf traits) and to the combination of all types of traits. The coefficients of determination (R2 adj) of the best multiple regression models were compared to determine the relative explanatory power of crown and leaf traits and a combination of both. Important Findings: The species-specific growth rates were not related to any of the single crown traits, but were related positively to leaf stomatal conductance and leaf water potential individually and negatively to leaf toughness, with approximately 13% variance explained by each of the traits. Combinations of different crown traits did not significantly explain the species-specific growth rates, whereas combinations of either physiological or morphological leaf traits explained 24% and 31%, respectively. A combination of both crown and leaf traits explained 42% of variance in species-specific growth rates. We concluded that sets of traits related to carbon assimilation at the leaf-level and to overall amount of leaves exposed at the crownlevel jointly explained species-specific growth rates better than either set of traits alone. [ABSTRACT FROM AUTHOR]

Aims: Plants with extrafloral nectaries (EFNs) are common in tropical and subtropical habitats and despite many other arthropods also forage for EFN, most studies solely focused on the defense mutualisms between EFN plants and ants. This study aims at a quantitative assessment of the entire arthropod community that visits EFN trees to compare visitor communities between different tree species to disentangle the mechanisms that may drive EFN visitor community composition. We also test for tree diversity effects on EFN visitors, as it is unknown if local tree species richness relates to the abundance and species richness of arthropods foraging for EFN. Methods: We sampled EFN-visiting arthropods in the experimental tree species richness gradient of the BEF-China Experiment, the currently largest forest diversity experiment in the world and tested if tree species richness affects EFN visitors and if visitor community composition differs between EFN tree species. In a second step, we analyzed the EFN of Ailanthus altissima and Triadica cochinchinensis, the two EFN tree species with highest visitor abundance, for sugars and amino acids (AA) to test if tree species-specific differences in nectar chemistry translate to differing visitor communities. Lastly, we conducted a choice experiment using different artificial nectar solutions to test if nectar quality affects foraging decisions of ants, the most frequent EFN visitors in our study sites. Important Findings: EFN trees in young successional forests in subtropical South-East China are visited by a diverse assemblage of arthropods including ants, beetles, flies and spiders. Albeit ants accounted for about 75% of all individuals, non-ant visitors were by far more species rich. Visitor abundance and species richness declined with increasing tree species richness, suggesting a resource dilution effect, because plots with more tree species had proportionally less EFN tree individuals and thus lower nectar availability. Ailanthus altissima and T. cochinchinensis were visited by different arthropods and their nectar had species-specific AA composition and sugar concentration, indicating that differences in visitors may, at least partly, be explained by differences in nectar chemistry. These findings are supported by the choice experiment, in which artificial nectars containing sugar solutions supplemented with essential AAs attracted more ants than pure sugar solutions or sugar solutions supplemented with non-essential AAs. Our results improve the understanding of the complex ecology of EFN trees, a plan life form that might be crucial for understanding how tree diversity influences patterns of tree growth in young successional tropical and subtropical forests. [ABSTRACT FROM AUTHOR]

The global extraction of forest and water resources has led to habitat degradation, biodiversity loss, and declines in ecosystem services. As a consequence, ecological restoration has become a global priority. Restoration efforts to offset this trend, however, are not always effective. One reason is that many restoration projects target single ecosystems and fail to acknowledge functional links between ecosystems. We synthesized current knowledge on links between forest and stream ecosystems, the effect of anthropogenic stressors on these links, and their implications for restoration planning. Many examples show that lateral subsidies, such as invertebrate prey and nutrients, are important in both terrestrial and aquatic environments. Stressors such as commercial forestry, flow regulation, stream channelization, and climate change affect these links and should be considered in restoration planning. Restoration practitioners are encouraged to view adjacent forest and stream ecosystems as one entity. [ABSTRACT FROM AUTHOR]

Misperceptions about the world's grassy biomes contribute to their alarming rates of loss due to conversion for agriculture and tree plantations, as well as to forest encroachment. To illustrate the causes and consequences of these misperceptions, we show that the World Resources Institute and the International Union for Conservation of Nature misidentified 9 million square kilometers of ancient grassy biomes as providing "opportunities" for forest restoration. Establishment of forests in these grasslands, savannas, and open-canopy woodlands would devastate biodiversity and ecosystem services. Such undesired outcomes are avoidable if the distinct ecologies and conservation needs of forest and grassy biomes become better integrated into science and policy. To start with, scientists should create maps that accurately depict grassy biomes at global and landscape scales. It is also crucial that international environmental agreements (e.g., the United Nations Framework Convention on Climate Change) formally recognize grassy biomes and their environmental values. [ABSTRACT FROM AUTHOR]

Intense hurricanes disturb many tropical forests, but the key mechanisms driving post-hurricane forest changes are not fully understood. In Puerto Rico, we used a replicated factorial experiment to determine the mechanisms of forest change associated with canopy openness and organic matter (debris) addition. Cascading effects from canopy openness accounted for most of the shifts in the forest biota and biotic processes, which included increased plant recruitment and richness, as well as the decreased abundance and diversity of several animal groups. Canopy opening decreased litterfall and litter moisture, thereby inhibiting lignin-degrading fungi, which slowed decomposition. Debris addition temporarily increased tree basal area. Elevated soil solution nitrate was a dominant response after past hurricanes; this effect only occurred in our experiment with simultaneous canopy-opening and debris treatments. Although debris is an important carbon and nutrient source, shortterm responses to cyclonic storms appear to be largely driven by canopy opening. [ABSTRACT FROM AUTHOR]

A price on carbon is driving land-use changes globally, including the establishment of biodiverse carbon plantings to sequester carbon. The biodiversity benefits of these plantings depend on many factors, including their spatial locations. We provide an approach for assessing the opportunities and spatial priorities for carbon sequestration and biodiversity restoration through biodiverse carbon plantings. Using Australia as a case study, we show how carbon market conditions affect the potential for achieving biodiversity benefits through restoring heavily cleared vegetation types to 30% of their original extent. Using a midrange carbon price, AU$20 per ton, we discovered that the top 25% of priority areas for biodiverse carbon plantings could sequester 132 megatons of carbon dioxide equivalents annually--more than 5% of Australia's emissions. Lower carbon prices limit biodiversity outcomes. Spatial priorities for sequestering carbon are different from those for restoring biodiversity; therefore, accounting for both factors maximizes efficiency and opportunities. [ABSTRACT FROM AUTHOR]

Numerous statistical models are employed when processing forest inventory data. These models primarily provide predicted values for attributes that are difficult and/or time-consuming to measure. In some applications, models are applied across a large geographic area, which assumes the relationship between the response variable and predictors is constant within the area. The extent to which this assumption holds for a tree height prediction model was evaluated at regional, eco province and eco section scales in the northeastern US. Two nonlinear regression models were tested, a spatially ambiguous model that utilized tree and stand-level predictors, and a spatially explicit model that incorporated latitude, longitude and elevation as predictors. When the regional-scale models were evaluated at the state level, both showed considerable bias for some states, which suggests that the statistical significance of spatial predictor variables does not translate into effective accounting for spatial variability. Similar results were obtained when fitting the model to an eco province and evaluating bias within eco sections. Finally, fitting the model to eco sections within the eco province provided a moderate level of local robustness as assessed by Moran's I statistic; however, there are cases where local biases may still exist. This outcome suggests that models should be developed and applied at small spatial scales to reduce local biases when model predictions are aggregated to larger geographic domains. Alternatively, more advanced modeling techniques may be more effective at addressing local variability using a single model having large-area application. However, the practicality of implementing these more complex techniques in the context of continuous large-area forest inventories is not well understood and should be fully explored prior to operational employment. [ABSTRACT FROM AUTHOR]

Forest products industry's competitiveness is influenced by the agility of wood procurement systems in delivering raw material to support downstream manufacturing activities. However, in a hierarchical forest management planning context, silvicultural treatments are prescribed and set as constraints for supply chain managers, restricting supply flexibility and consequently value-adding potential. This study was conducted with an objective of quantifying the benefits of improving wood procurement systems agility through flexibility in the choice of silvicultural treatments at the operational level. The aim was also to determine the range of conditions under which benefits from flexibility can be realized while accounting for the impact on long-term supply. We present a novel approach that integrates silvicultural options into operational-level decision-making to solve the multi-product, multi industry problem with divergent flow. The approach entails solving a mixed integer programming model in a rolling planning horizon framework. Subsequently, we demonstrate benefits associated with integrating supply chain and silvicultural decisions through a case study. Future impact of exercising flexibility on long-term supply was accounted through incorporating costs associated with applying different silvicultural regimes. The presented approach will prove to be useful in implementing an adaptive forest management system that integrates the complexity of social, economic and ecological dimensions. [ABSTRACT FROM AUTHOR]

The contribution of understorey vegetation (UVEG) to forest ecosystem biomass and carbon (C) across diverse forest types has, to date, eluded quantification at regional and national scales. Efforts to quantify UVEG C have been limited to field-intensive studies or broad-scale modelling approaches lacking field measurements. Although large-scale inventories of UVEG C are not common, species- and community-level inventories of vegetation structure are available and may prove useful in quantifying UVEG C stocks. This analysis developed a general framework for estimating UVEG C stocks by employing per cent cover estimates of UVEG from a region-wide forest inventory coupled with an estimate of maximum UVEG C across the US Lake States (i.e. Michigan, Minnesota and Wisconsin). Estimates of UVEG C stocks from this approach reasonably align with expected C stocks in the study region, ranging from 0.86 ± 0.06 Mg ha−1 in red pine-dominated to 1.59 ± 0.06 Mg ha−1 for aspen/birch-dominated forest types. Although the data employed here were originally collected to assess broad-scale forest structure and diversity, this study proposes a framework for using UVEG inventories as a foundation for estimating C stocks in an often overlooked, yet important ecosystem C pool. [ABSTRACT FROM AUTHOR]

Numerous hypotheses have been proposed for the historical processes governing the rich endemism of Madagascar's biodiversity. The 'watershed model' suggests that drier climates in the recent geological past have resulted in the contraction of forests around major watersheds, thereby defining areas of endemism. We test whether this hypothesis explains phylogeographical patterns in a dry forest-dependent rodent, E liurus myoxinus, an endemic species widely distributed through western Madagascar. We sequenced the mitochondrial cytochrome b locus and nuclear introns of the β-fibrinogen and the growth hormone receptor genes for E. myoxinus. Using a parametric bootstrapping approach, we tested whether the mitochondrial gene tree data fit expectations of local differentiation given the watershed model. We additionally estimated population differentiation and historical demographic parameters, and reconstructed the spatial history of E. myoxinus to highlight spatial and temporal patterns of differentiation. The data do not support the watershed model as a clear explanation for the genetic patterns of diversity within extant E. myoxinus populations. We find striking patterns of latitudinal genetic structure within western Madagascar, and indicate possible roles for environmental and ecological gradients along this axis in generating phylogeographical diversity. © 2013 The Linnean Society of London, Biological Journal of the Linnean Society, 2013, 110, 500-517. [ABSTRACT FROM AUTHOR]

Aim Due to the important role of lianas in the functioning of forest ecosystem, knowledge of the factors that affect them are important in the management of forests. Currently, there are conflicting reports on the response of liana communities to disturbance, calling for more research in the area. The present study was carried out to investigate the response of liana diversity and structure to human disturbance within two major forests in the Penang National Park, Malaysia. The study also looked at the implication of the findings for conservation. Methods A total of 15 40 × 40-m2 (or 40-m × 40-m) plots each were randomly located across a range of habitats in a primary forest and disturbed secondary forest. Trees with diameter at breast height ≥10 cm were examined for lianas with diameter ≥2 cm. Both lianas and trees were enumerated and compared between the two forests. Diversity and structural variables of lianas were compared between the two forests using the t-test analysis. Tree abundance was also compared between the two forests with t-test, while linear regression analysis was run to determine the effects of tree abundance on liana abundance. Important Findings A total of 46 liana species belonging to 27 genera and 15 families were identified in the study. Human disturbance significantly reduced liana species richness and species diversity in the secondary forest. Liana abundance remained the same in both forests whereas liana basal area was significantly higher in the primary forest. Twiners and hook climbers were significantly more abundant in the primary and secondary forest, respectively. Large diameter lianas were more abundant in the primary forest compared with the secondary forest. The diameter distribution of most families in the primary forest followed the inverted J-shaped curve whereas only a few of the families in the secondary forest did so. Tree abundance was significantly higher in the primary forest. The abundance of lianas significantly depended on tree abundance in all the forests. The study has provided evidence of negative effects of human disturbance on liana diversity and structure that does not auger well for biodiversity in the forest. In view of the critical role of lianas in maintaining biodiversity in the forest ecosystem, lianas in the national park should be protected from further exploitation. [ABSTRACT FROM PUBLISHER]

A pan-European effort to harmonize national forest inventories (NFl) was initiated under COST Action E43, "Harmonisation of National Forest Inventories in Europe: Techniques for Common Reporting." More than 30 countries and institutions, mainly from Europe, and multiple international institutions joined the Action, which was initiated in 2004. The main objective was to improve existing European NFIs by harmonizing information through development of and agreement on common inventory definitions. Other objectives were to support countries in the development of new sample-based forest inventories that satisfy national, European, and global requirements for timely, harmonized, and transparent forest resource information and to promote the use of scientifically sound and validated methods in forest inventory designs, data collection, and data analysis. The Action developed and agreed on "reference definitions" as the formal basis for harmonized reporting of general forest status and forest biodiversity to the United Nations Framework Convention on Climate Change and its Kyoto Protocol. Complete or partial agreement was reached on 78 of 99 inventory-related definitions. Methods called bridges were developed to adjust an estimate based on a local or national definition to correspond to a reference definition. Forest inventory variables applicable as common biodiversity indicators were also identified. The objectives of this article were to describe the background of COST Action E43, to motivate the importance of the work, and to present the main approaches and achievements, as well as to discuss possibilities for harmonized estimation when inventory definitions vary. The article also serves as an introduction to the other COST Action E43 articles in this special issue of Forest Science. [ABSTRACT FROM AUTHOR]

In the Central Asian deserts, the floodplains along the large river systems like the Amu Darya, Syr Darya and Tarim harbour the highest biodiversity and provide a wide range of ecosystem services for men in those regions. Against the background of the potential use of wood biomass and carbon sequestration, we investigate the biomass of floodplain forest (Tugai) ecosystems along the Tarim River, north-west China, and the Amu Darya, Turkmenistan. These forests are dominated by Populus euphratica Oliv. Under very good water supply conditions, the stand biomass, comprising above- and below-ground components of P. euphratica, was 58.4 t ha−1, corresponding with the highest tree densities. The stand biomass of P. euphratica under non-optimal conditions, i.e. prolonged flooding or periods of drought with sinking groundwater levels, ranged from 16 to 28 t ha−1. The observed stand biomass values for P. euphratica are in the range of values found by others in Xinjiang and Inner Mongolia, China, but lower than the biomass of temperate forests. However, among the desert, semi-desert and steppe ecosystems, the riparian P. euphratica forest is the ecosystem with the highest above-ground biomass. Thus, the riparian forests in Central Asia contain a regionally remarkable amount of biomass. [ABSTRACT FROM AUTHOR]

Aims Mechanisms contributing to species coexistence have at least one of two modes of action: (i) stabilization of populations through restoring forces and (ii) equalization of fitness across individuals of different species. Recently, ecologists have begun gleaning the relative roles of these by testing the predictions of neutral theory, which predicts the properties of communities under pure fitness equalization. This null hypothesis was rejected for forests of southern Ontario based on large-scale (∼100 km) spatial synchrony evident in the fossil pollen record over the entire Holocene, and the argument that a species' relative abundance would instead vary independently at such distances in the absence of stabilizing mechanisms. This test of neutral theory was criticized based on the idea that the synchrony might be produced by dispersal alone. Here, I revisit this test of neutral theory by explicitly calculating the synchrony expected in these forests using a novel simulation method enabling examination of the distribution of a species over large spatial and temporal scales. Methods A novel neutral simulation algorithm tracking only the focal species was used to calculate the neutral expectation for spatial synchrony properties examined empirically by Clark and MacLachlan [(2003) Stability of forest biodiversity. Nature 423:635–8] using fossil pollen data from eight lake sites. The coefficient of variation (CV) in a species' relative abundance across the eight sites (initiated at about 10% with a small CV) was calculated for 10 runs over a 10 000 year time interval. The CV reflects the level of spatial synchrony in that less synchronous dynamics should lead to more variation across space (a higher equilibrium CV), and in particular, a greater increase in the CV over time from a small initial value. A ‘two dimensional t’ fat-tailed dispersal kernel was assumed with parameters set to the median derived from seed trap data for deciduous wind-dispersed trees. Robustness of results to assumed dispersal distance, density of trees on the landscape, site sizes, age at maturity and starting spatial distribution were checked. Important Findings In contrast to the prediction of Clark and MacLachlan that, in the absence of stabilization, the CV across the sites should increase over time from levels observed at the beginning of the Holocene, under fat-tailed dispersal my neutral model robustly predicted only a brief (50 years) and small increase in the CV. I conclude that purely fitness-equalized species coexistence cannot be rejected based on the observed lack of increase in the CV across the eight sites in southern Ontario over the Holocene. Synchronous variation in environmental factors could alternatively explain the observed synchrony without the need for stabilization. However, neither dispersal nor environmental synchrony seems likely explanations for the quick widespread recovery of Tsuga in the Holocene after its seeming decimation, likely due to a pest outbreak. [ABSTRACT FROM PUBLISHER]

Biodiversity is integral to almost all ecosystem processes, with some species playing key functional roles that are essential for maintaining the value of ecosystems to humans. However, many ecosystem services remain nonvalued, and decisionmakers rarely consider biodiversity in policy development, in part because the relationships between biodiversity and the provision of ecosystem services are not generally appreciated. To date, the majority of work in which the functional importance of biodiversity has been examined has been conducted in relatively species-poor systems. Focusing on forest and agroforest systems, we synthesize recent research on the role of biodiversity in the provision of ecosystem services and provide examples of biodiversity science that informs ecosystem management and policy. Finally, we highlight barriers to the transfer of knowledge from scientists to decisionmakers and suggest that scientists can be much more effective at informing policy and improving resource management by asking policy-relevant questions and providing timely and consistent information to decisionmakers and the public on the linkages among biodiversity, ecosystem services, and their value to people. [ABSTRACT FROM AUTHOR]

Based on a literature review and on a new bioeconomic modelling approach, we investigated whether or not clear-cutting and mono-species forests are the optimal silvicultural strategies under the presence of risk. The model reflects a risk-avoiding attitude and builds upon portfolio theory. The selected tree species and the timing of regeneration harvests constitute a total of 22 management alternatives. Optimal area fractions of the alternatives were combined at the stand level to find the maximum value at risk (VaR, annualized net present value exceeded with probability of 0.99). Relevant uncertainties were integrated via Monte Carlo Simulation and bootstrapping. The results showed a maximum VaR for a highly diversified treatment combining 42 per cent Norway spruce and 58 per cent European beech and included area fractions with regeneration harvests from age 50 to 120 years. This treatment avoids clear-cutting and a mono-species forest composition. It uses tree species diversification and extends the regeneration period over 70 years to diversify hazard and price risks. The resulting scenario may be called ‘near-natural’ and emerges as the optimal choice, particularly for cautious, and thus risk-avoiding forest owners who do not have the opportunity to diversify risks by means of large-scale forest properties. [ABSTRACT FROM AUTHOR]

Almost all commercial forests of Finland are simultaneously used for timber production, outdoor recreation and biodiversity maintenance. For the past 60 years, the official line of silviculture has been even-aged management. However, uneven-aged management and other forms of continuous cover forestry are gradually gaining popularity and also official acceptance. This study analyzed variable density thinning (VDT) in the context of uneven-aged management of Norway spruce (Picea abies L.Karsten) stands. The aim was to find economically profitable management systems, which would result in forests that are good for recreation and biodiversity maintenance. The stand compartment was divided into cutting segments and only one segment was harvested at a time. When economic profitability was maximized as the sole management objective, 15-year cutting cycle with uniform thinning (UT) was the optimal management system. All trees larger than 19 cm in diameter at breast height (all saw log-sized trees) were removed in the cutting. When a continuous presence of large trees was required, VDT was clearly more profitable than UT. In VDT, all large trees were removed from the thinned places but there were large trees in the segments that will be cut in the next logging operation. The optimal cutting cycle (interval between successive cuttings in the same place) of VDT was 20–30 years when large trees were required in the post-cutting forest. Several combinations of the length of cutting cycle and number of cutting segments were nearly equally profitable. Profitable options were, for instance, to divide the stand into four cutting segments each cut at 20-year interval or three segments each cut at 30-year interval. [ABSTRACT FROM AUTHOR]

Gravitropism is necessary for plants to control the orientation of their axes while they grow in height. In woody plants, stem re-orientations are costly because they are achieved through diameter growth. The functional diversity of gravitropism was studied to check if the mechanisms involved and their efficiency may contribute to the differentiation of height growth strategies between forest tree species at the seedling stage. Seedlings of eight tropical species were grown tilted in a greenhouse, and their up-righting movement and diameter growth were measured over three months. Morphological, anatomical, and biomechanical traits were measured at the end of the survey. Curvature analysis was used to analyse the up-righting response along the stems. Variations in stem curvature depend on diameter growth, size effects, the increase in self-weight, and the efficiency of the gravitropic reaction. A biomechanical model was used to separate these contributions. Results showed that (i) gravitropic movements were based on a common mechanism associated to similar dynamic patterns, (ii) clear differences in efficiency (defined as the change in curvature achieved during an elementary diameter increment for a given stem diameter) existed between species, (iii) the equilibrium angle of the stem and the anatomical characters associated with the efficiency of the reaction also differed between species, and (iv) the differences in gravitropic reaction were related to the light requirements: heliophilic species, compared to more shade-tolerant species, had a larger efficiency and an equilibrium angle closer to vertical. This suggests that traits determining the gravitropic reaction are related to the strategy of light interception and may contribute to the differentiation of ecological strategies promoting the maintenance of biodiversity in tropical rainforests. [ABSTRACT FROM PUBLISHER]

Common walnut (Juglans regia L.) is usually grown in pure stands or as individual trees, rather than within mixed woodlands. Previous studies indicate that walnut can benefit from being planted in mixed stands, particularly with nitrogen-fixing (N-fixing) species. The effects of establishing walnut with various combinations of tree and shrub nurse species were investigated, including those capable of fixing nitrogen. After 6 years, walnut survival exceeded 99 per cent. Tree nurses did not significantly effect walnut growth; however, walnut height growth with autumn olive (Elaeagnus umbellata Thunb.) was significantly greater (P < 0.05), with an average increment of 17 cm year-1 across all sites at year six and 32 cm year-1 at one site at year seven. The architecture (height, width and estimated volume) of Corylus avellana L. and E. umbellata had a significant positive (P < 0.05) effect on walnut height. Foliar nitrogen levels for walnuts with at least one N-fixing nurse were within the reported optimal range, whereas those walnuts in control plots were deficient in nitrogen. Walnut trees grown with E. umbellata also had fewer multiple stems and finer branches. The results indicate that there are significant early benefits from establishing walnut with E. umbellata. [ABSTRACT FROM AUTHOR]

Natural regeneration of stone pine (Pinus pinea L.) in the Northern Plateau of Spain is fraught with problems and, consequently, difficult to attain. In this study, we start by describing the spatial structure of one even-aged and one uneven multi-aged stand as a first step towards understanding the processes that produce the spatial patterns and, in turn, provide managers with information that could help to enhance regeneration. All trees were mapped and located through their xy coordinates and two perpendicular crown diameter measurements were recorded for each tree in addition to other structural variables. A grid-based approach, in which crowns were projected on a grid, was then used to characterize the spatial pattern and this was compared with the conventional point pattern analysis. This allowed us to take into account variations in crown size and shape. Regeneration was found to be clumped in both stands and the spatial association with stems varied among the age classes considered. Results from the crown pattern analysis differed from those obtained using the traditional point pattern analysis, especially in the older age classes, where crowns were larger and had a greater influence on regeneration. Our results suggest that where large variations in crown dimensions exist, the use of this method can help us to avoid misinterpretations of the results and provide further insight into the processes that drive natural regeneration. [ABSTRACT FROM AUTHOR]