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Aims: Primary forests provide critical habitat and diverse ecological niches for bird species, which are being seriously threatened by massive anthropogenic activities in the Anthropocene. Conversion from primary forests to secondary forests and plantation forests results in biodiversity loss, reducing ecosystem functioning and services. However, few studies have evaluated bird diversity patterns in different forest types caused by anthropogenic activities at both pantropics and regional scales, especially from taxonomic, phylogenetic and functional perspective simultaneously, as well as from the perspective of both alpha and beta diversity. Location: Pantropics. Methods: We analysed patterns of bird diversity in primary forests, secondary forests and plantation forests at pantropics and regional scales. Number of threatened species, rare species, and generalist species in the three forest types were summarized. Taxonomic, phylogenetic and functional diversity, as well as phylogenetic and functional structure of bird communities among the three forest types, were evaluated through multiple comparisons. Beta diversity of bird communities in the three forest types was also calculated and decomposed into turnover and nestedness‐resultant components, and correlations between environmental factors and beta diversity were examined. Results: The results showed that primary forests harboured more threatened species, more large species and specialist species than secondary forests and plantation forests. In addition, plantation forests had lower phylogenetic alpha diversity but higher functional alpha diversity, and had more clustered phylogenetic structure but more over‐dispersed functional structure. Notably, taxonomic, phylogenetic and functional beta diversity of bird communities was significantly higher in primary forests than in plantation forests, and turnover components showed similar patterns and accounted for major parts of overall beta diversity. Main Conclusions: These findings suggest that primary forests play an important role in protecting bird taxonomic, phylogenetic and functional diversity, and emphasize that future conservation efforts should focus on the strict protection of primary forests. [ABSTRACT FROM AUTHOR]

Protecting forest ecosystems is a critical action for addressing both the climate and biodiversity crises. Effective long-term management of forests requires landscape approaches, but evaluating the management actions is a key challenge. Previous research has suggested evaluation should focus on three interrelated pillars: ecosystem integrity, effective planning, and strong governance. This paper presents a framework for evaluating ecosystem integrity based on the 'Principle, Criteria, Indicator and Verifier' (PCIV) method. The key principle used is ecosystem autopoiesis – the ability of a system for self-generation and maintenance by creating its own parts. Four key criteria are applied, accompanied by a set of nine indicators. Verifiers for each indicator are suggested for which feasible data sources are likely available. The use of the three-pillar framework, including ecosystem integrity, is illustrated using three hypothetical cases representing different forest landscape contexts. Such evaluation can provide practical, consistent, repeatable, and comparable information for stakeholders and decision makers. [ABSTRACT FROM AUTHOR]

Assessing the impacts of natural disturbance on the functioning of complex forest systems are imperative in the context of global change. The unprecedented rate of contemporary species extirpations, coupled with widely held expectations that future disturbance intensity will increase with warming, highlights a need to better understand how natural processes structure habitat availability in forest ecosystems. Standardised typologies of tree-related microhabitats (TreMs) have been developed to facilitate assessments of resource availability for multiple taxa. However, natural disturbance effects on TreM diversity have never been assessed. We amassed a comprehensive dataset of TreM occurrences and a concomitant 300-year disturbance history reconstruction that spanned large environmental gradients in temperate primary forests. We used nonlinear analyses to quantify relations between past disturbance parameters and contemporary patterns of TreM occurrence. Our results reveal that natural forest dynamics, characterised by fluctuating disturbance intervals and variable severity levels, maintained structurally complex landscapes rich in TreMs. Different microhabitat types developed over time in response to divergent disturbance histories. The relative abundance of alternate TreMs was maximised by unique interactions between past disturbance severity and elapsed time. Despite an unequal distribution of individual TreMs, total microhabitat diversity was maintained at constant levels, suggesting that spatially heterogeneous disturbances maintained a shifting mosaic of habitat types over the region as a whole. Our findings underscore the fundamental role of natural processes in promoting conditions that maximise biodiversity potential. Strict conservation and management systems that preserve natural disturbance outcomes, including associated biological legacies, may therefore safeguard biodiversity at large scales. [ABSTRACT FROM AUTHOR]

I investigated the size, composition and persistence of the seed-bank in primary forests, secondary forests and old-fields in southern Mexico. I also assessed the contribution of the seed-bank to regeneration relative to other propagule sources. In all habitats, I removed by hand all plants and litter and excluded the seed-rain. For one year, I counted the number of plant species (5–50 cm tall) emerged and grouped them into different growth-forms: trees, shrubs, palms, herbs, woody lianas, epiphytes and hemi-epiphytes. A total of 95 species emerged. The seed-bank size, composition and persistence showed strong variation among successional stages. Emergence was low for primary and secondary forests, but high for old-fields (19, 26, and 68 plants per m−2, respectively). Herbs were the most abundant in the seed-bank and palms the less. Time had a negative effect on seed-bank size in primary forests and old-fields; whereas for secondary forests size remained constant throughout the year. The number of emerged plants in different growth-forms changed significantly across time for all successional stages. Overall, the seed-bank provided a greater number of plants in old-fields relative to other propagule sources combined. The results showed that forest modification alters the input of propagules throughout the seed-bank for different plant growth-forms. [ABSTRACT FROM AUTHOR]

Protecting structural features, such as tree‐related microhabitats (TreMs), is a cost‐effective tool crucial for biodiversity conservation applicable to large forested landscapes. Although the development of TreMs is influenced by tree diameter, species, and vitality, the relationships between tree age and TreM profile remain poorly understood. Using a tree‐ring‐based approach and a large data set of 8038 trees, we modeled the effects of tree age, diameter, and site characteristics on TreM richness and occurrence across some of the most intact primary temperate forests in Europe, including mixed beech and spruce forests. We observed an overall increase in TreM richness on old and large trees in both forest types. The occurrence of specific TreM groups was variably related to tree age and diameter, but some TreM groups (e.g., epiphytes) had a stronger positive relationship with tree species and elevation. Although many TreM groups were positively associated with tree age and diameter, only two TreM groups in spruce stands reacted exclusively to tree age (insect galleries and exposed sapwood) without responding to diameter. Thus, the retention of trees for conservation purposes based on tree diameter appears to be a generally feasible approach with a rather low risk of underrepresentation of TreMs. Because greater tree age and diameter positively affected TreM development, placing a greater emphasis on conserving large trees and allowing them to reach older ages, for example, through the establishment of conservation reserves, would better maintain the continuity of TreM resource and associated biodiversity. However, this approach may be difficult due to the widespread intensification of forest management and global climate change. [ABSTRACT FROM AUTHOR]

Along with the accumulation of atmospheric greenhouse gases, particularly carbon dioxide, the loss of primary forests and other natural ecosystems is a major disruption of the Earth's system and is causing global concern. Quantifying planetary warming from carbon emissions, global climate models highlight natural forests' high carbon storage potential supporting conservation policies. However, some model outcomes effectively deprioritize conservation of boreal and temperate forests by suggesting that increased albedo upon deforestation could cool the planet. A potential conflict of global cooling vs. regional forest conservation could harm environmental policies. Here we present theoretical and observational evidence to demonstrate that, compared to the carbon-related warming, modeling skills for assessing climatic impacts of deforestation is low. We argue that estimates for deforestation-induced global cooling result from the models' limited capacity to account for the global effect of cooling from evapotranspiration of intact forests. Specifically, transpiration of trees can change the greenhouse effect via small modifications of the vertical temperature profile. However, due to their convective parameterization (which postulates a certain critical temperature profile), global climate models do not properly capture this effect. This may lead to an underestimation of warming from the loss of forest evapotranspiration in both high and low latitudes. As a result, conclusions about deforestation-induced global cooling are not robust and could result in action that immediately worsened global warming. To avoid deepening the environmental crisis, these conclusions should not inform policies of vegetation cover management, especially as studies from multiple fields are accumulating that better quantify the stabilizing impact of natural ecosystems evolved to maintain environmental homeostasis. Given the critical state and our limited understanding of both climate and ecosystems, an optimal policy with immediate benefits would be a global moratorium on the exploitation of all natural forests.

The impact of land-use change (LUC) on soil organic carbon (SOC) has been a wide concern of land management policymakers because CO _2 emissions induced by LUC have been the second largest carbon source worldwide. However, due to insufficient data quality and limited biome coverage, a global big picture of the impact of LUC on SOC is still not clear. This study conducted a meta-analysis on 288 independent observations sourced from 62 peer-reviewed papers to provide a global summary of the change in SOC after the conversion of primary forests into other land-use types. The conversion of primary forest to cropland resulted in the most severe SOC loss (−33.2%), followed by conversion into plantation forests (−22.3%) and secondary forests (−19.1%). Nonetheless, SOC increased by 9.1% after a conversion from primary forests into pasture. More SOC loss was found at sites with lower precipitation for primary forests converted to cropland and plantation forests. The SOC loss decreased consistently with increasing mean annual temperature (MAT) for all four types of LUC. Moreover, the loss of SOC tended to worsen over time when primary forests are converted to cropland or plantation forests. In contrast, SOC loss recovered over time following conversion to secondary forests. The gain of SOC gradually increased over time after conversion to pastures. To conclude, the changes in SOC are related not only to the land-use type but also to precipitation, temperature and turn years after LUC. Due to limited data, this study focuses on soil profiles within 30 cm depth, and future research should explore SOC dynamics induced by LUC at greater depths. Overall, cases of SOC loss of approximately 30% following deforestation were very common (except for conversion to pasture), and the results of this study show that the loss of SOC following LUC should be carefully considered and monitored in land management.

Across the boreal biome, clear‐cutting of old, previously non clear‐cut forests with high naturalness followed by tree planting or seeding is a major land use change. However, how much previously uncut forest has been converted to plantations remains unquantified. We combine Swedish national databases on clear‐cuts and forest inventories to show that at least 19% of all clear‐cuts since 2003 have occurred in old forests that were most likely not previously cut and planted or seeded. Old forests have been cut and lost at a steady rate of ∼1.4% per year for the same period, and at this rate they will disappear by the 2070s. There is further evidence that this type of unreported forest conversion is occurring across much of the world's boreal forest. Plain Language Summary: Natural ecosystems that have seen limited direct human impact are threatened by land use change. Land use in boreal regions is dominated by forestry but the rate at which older boreal forests with high naturalness are converted to planted and seeded forest for wood harvesting remains unquantified. We used a set of uniquely detailed databases and maps to estimate the share of old and previously uncut forests in annual harvests and at which rate these forests are being lost in Sweden. The results indicate that about a fifth of cut forest area since 2003 was cuts of previously uncut old forest. If the present trajectory continues, the remaining unprotected old and previously uncut forests will be converted to planted and seeded managed forests within a couple of decades. Given the slow development and distinct structural and ecological characteristics of these old forests, this loss may define the landscape for centuries. Key Points: Old previously uncut boreal forests are cut at a fast rateThe conversions of natural boreal forests to planted and seeded managed forests are not monitoredThe slow growth of boreal forests implies that the present natural to managed forest conversions may define the landscapes for centuries [ABSTRACT FROM AUTHOR]

Abstract Across the boreal biome, clear‐cutting of old, previously non clear‐cut forests with high naturalness followed by tree planting or seeding is a major land use change. However, how much previously uncut forest has been converted to plantations remains unquantified. We combine Swedish national databases on clear‐cuts and forest inventories to show that at least 19% of all clear‐cuts since 2003 have occurred in old forests that were most likely not previously cut and planted or seeded. Old forests have been cut and lost at a steady rate of ∼1.4% per year for the same period, and at this rate they will disappear by the 2070s. There is further evidence that this type of unreported forest conversion is occurring across much of the world's boreal forest.

I investigated the size, composition and persistence of the seed-bank in primary forests, secondary forests and old-fields in southern Mexico. I also assessed the contribution of the seed-bank to regeneration relative to other propagule sources. In all habitats, I removed by hand all plants and litter and excluded the seed-rain. For one year, I counted the number of plant species (5–50 cm tall) emerged and grouped them into different growth-forms: trees, shrubs, palms, herbs, woody lianas, epiphytes and hemi-epiphytes. A total of 95 species emerged. The seed-bank size, composition and persistence showed strong variation among successional stages. Emergence was low for primary and secondary forests, but high for old-fields (19, 26, and 68 plants per m−2, respectively). Herbs were the most abundant in the seed-bank and palms the less. Time had a negative effect on seed-bank size in primary forests and old-fields; whereas for secondary forests size remained constant throughout the year. The number of emerged plants in different growth-forms changed significantly across time for all successional stages. Overall, the seed-bank provided a greater number of plants in old-fields relative to other propagule sources combined. The results showed that forest modification alters the input of propagules throughout the seed-bank for different plant growth-forms.

Deforestation and forest degradation from human land use, including primary forest loss, are of growing concern. The conservation of old-growth and other forests with important environmental values is central to many international initiatives aimed at protecting biodiversity, mitigating climate change impacts, and supporting sustainable livelihoods. Current remote-sensing products largely focus on deforestation rather than forest degradation and are dependent on machine learning, calibrated with extensive field measurements. To help address this, we developed a novel approach for mapping forest ecosystem stability, defined in terms of constancy, which is a key characteristic of long-undisturbed (including primary) forests. Our approach categorizes forests into stability classes based on satellite-data time series related to plant water–carbon relationships. Specifically, we used long-term dynamics of the fraction of photosynthetically active radiation intercepted by the canopy (fPAR) and shortwave infrared water stress index (SIWSI) derived from the Moderate Resolution Imaging Spectroradiometer (MODIS) for the period 2003–2018. We calculated a set of variables from annual time series of fPAR and SIWSI for representative forest regions at opposite ends of Earth's climatic and latitudinal gradients: boreal forests of Siberia (southern taiga, Russia) and tropical rainforests of the Amazon basin (Kayapó territory, Brazil). Independent validation drew upon high-resolution Landsat imagery and forest cover change data. The results indicate that the proposed approach is accurate and applicable across forest biomes and, thereby, provides a timely and transferrable method to aid in the identification and conservation of stable forests. Information on the location of less stable forests is equally relevant for ecological restoration, reforestation, and proforestation activities. [ABSTRACT FROM AUTHOR]

Forests are critical for biodiversity conservation and climate change mitigation: reducing emissions, increasing removals, and providing resilient ecosystems with stable long‐term carbon storage. However, evaluating the mitigation effectiveness of forests managed for conservation versus commodity production has been long debated. We assessed factors influencing evaluation of mitigation effectiveness––land area, time horizon, reference level, carbon stock longevity––and tested the outcomes using analyses of carbon dynamics from an Australian ecosystem. Results showed that landscape scale accounting using carbon carrying capacity as the reference level and assessed over a series of time horizons best enables explicit evaluation of mitigation benefits. Time horizons need to differentiate between near‐term emissions reduction targets (2030 and 2050), relative longevity of carbon stocks in different reservoirs, and long‐term impacts on atmospheric CO2 concentration. Greatest mitigation benefits derive from conservation through continued forest growth (52% gain in carbon stock by 2050) and accumulating carbon to attain carbon retention potential (70% gain). Cumulative emissions from harvesting result in permanent elevation of atmospheric CO2 concentration (32 times the annual emission by rotation end). We recommend these time horizons and landscape scales for evaluating forest management to better guide policies and investments for achieving climate mitigation and biodiversity conservation. [ABSTRACT FROM AUTHOR]

Despite Connecticut's 350+ years of logging history, there remains an appreciable acreage of small, isolated stands of 200+-year-old forests, most of which are in their original state or nearly so. The three primary forest communities discussed here are classified by their dominant tree species: ridges with eastern red cedar, ravines with eastern hemlock, and acidic, boreal swamps with black gum. The old-growth eastern red cedars occur throughout the Metacomet traprock ridges, which run north to south along central Connecticut. The old-growth eastern hemlocks are found in remote, steep ravines mostly within the Litchfield Hills and Connecticut's northwest corner. Isolated acidic boreal black gum/red spruce swamps are concentrated in high-altitude, shallow basins in the Litchfield Hills and the Quiet Corner (Northeastern Connecticut). [ABSTRACT FROM AUTHOR]

Boreal forest ecosystems are predicted to experience more frequent summer droughts due to climate change, posing a threat to future forest health and carbon sequestration. Forestry is a regionally dominant land use where the managed secondary forests are typically even-aged forests with low structural and tree species diversity. It is not well known if managed secondary forests and unmanaged primary forests respond to drought differently in part because the location of primary, unmanaged, forests has remained largely unknown. Here we employed a unique map detailing over 300 primary forests in Sweden. We studied impacts of the 2018 nationwide drought by extracting and analyzing a high-resolution remote sensing vegetation index over the primary forests and over buffer zones around the primary forests representing secondary forests. We controlled for topographical variations linked to soil moisture, which was a strong determinant of drought responses, and analyzed Landsat-derived EVI2 anomalies during the drought year from a multiyear non-drought baseline. We found that primary forests were less affected by the drought compared to secondary forests. Our results indicate that forestry may exacerbate the impact of drought in a future climate with more frequent and extreme hydroclimatic events.

The assessment of the succession status and the forecast of the development of pine forests depend on their origin and need a detailed study of historical and modern fire regimes. This article summarises the information on the dynamics of fires in the forests of the plain area in the Pechora-Ilych Biosphere Reserve (Russia) before 1942. Current forest fires in the pine forests in the Pechora-Ilych Biosphere Reserve are a legacy of previous traditional land use on this territory. Thanks to the material analysis of the first forest inventory, the condition of the forests of the plain area was assessed for the first time 10 years after the foundation of the Pechora-Ilych Biosphere Reserve. It was shown that about 50% of the forests of the modern plain area (most of the lichen, green moss-lichen and green moss-shrub communities) at that time were already touched by ground and crown fires. The population got accustomed to the smoke along the tributaries of the Pechora and the Ilych rivers, so that they reflected it in the names. Perhaps, for several centuries, fires were initiated by the Mansi, who used this territory as winter pastures until the middle of the 19th century. Eventually, a small human population actively visited the forests having the purpose of logging, hunting, gathering of wild-growing plants and fishing. The interfluve of the Pechora and Ilych rivers was a mosaic of land, divided between the inhabitants of various villages. Careless handling of fire led to numerous uncontrolled fires that no one put out and as a result, vast territories of forests were burnt. After the formation of the Pechora-Ilych Biosphere Reserve, these pine forests continued to burn, but much less. Since the plain area adjoins the navigable River Pechora, the anthropogenic causes of these fires cannot be completely ruled out. At the same time, we do not exclude the possibility of fires from dry thunderstorms. However, when assessing the modern fire regime, it is important to remember that the high fire danger in these forests is a legacy of previous impacts, which requires further study.

Ants are omnipresent in tropical forests, especially territorially dominant arboreal ants whose territories are spatially segregated forming 'ant mosaics'. These ecologically important species are rarely used in conservation monitoring because of the difficulty in collecting them. We developed a standardised baitline protocol to study the distribution of dominant ants on canopy trees and also a procedure to objectively define species dominance, even in unknown ant assemblages.Besides eliminating the need to climb trees, this protocol allows live arboreal ant specimens to be sampled at different heights. Behavioural aggressiveness assays between the collected workers provide data on the three‐dimensional distribution of colonies and on interactions between species. We compared the results of the behavioural tests to those from null models.In the New Guinean lowland forest studied, we show that the canopy was either shared by multiple territorial species or inhabited by a single species with a large territory. The baitline protocol collected up to half of the arboreal ant species found in a felling census. However, the proportion of species collected at baits decreased with the increasing spatial dominance of single territorial species.Behavioural observations used in the protocol allowed a more efficient detection of ant mosaics than null models. Territorially dominant ants were active on both understorey and canopy trees.The protocol is fast and easy to replicate. It is a potential tool for understanding and monitoring the spatiotemporal dynamics of arboreal ant assemblages and can detect populous colonies, including those of invasive species. [ABSTRACT FROM AUTHOR]

The natural and old-growth forests and their associated biodiversity continues to fade worldwide due to anthropogenic impact in various forms. The boreal forests in Fennoscandia have been subject to intensive clearfelling forestry since the middle of twentieth century. As a result, only a fraction of forests with long temporal continuity remains at the landscape level. In Sweden, some of these primary forests have been formally protected, whereas other forests with known high conservation values are not. Collectively, both protected and not protected known valuable primary forests are included in a nationally delineated network of high conservation value forests (HCVF). In addition to HCVF, older forests that have not been clearfelled since the mid-1900s, i.e., “proxy continuity forests,” have recently been mapped across the entire boreal biome in Sweden. In this paper, we analyze how these proxy continuity forests may strengthen the HCVF network from a green infrastructure perspective. First, we evaluate the spatial overlap between proxy continuity forests and HCVF. Second, we perform a large-scale connectivity analysis, in which we show that adding proxy continuity forests located outside HCVF strongly increases the structural connectivity of the network of protected forests. Finally, by assessing habitat suitability for virtual species specialized in pine, spruce, and broadleaf forests, we find large regional differences in the ability to secure habitat and thereby functional green infrastructure by considering currently unprotected primary forest. We show that, by adding those forests to the network, the area of habitat for low-demanding species dependent on spruce or pine forests can be largely increased. For high-demanding species, additional habitat restoration in the landscape matrix is needed. By contrast, even counting all valuable broadleaf forests available is not enough to provide a suitable habitat for their associated species, which indicates a large need for landscape-scale habitat restoration initiatives, in particular, for broadleaf forests.

Investigating temporal variation in soil bacterial communities advances our fundamental understanding of the causal processes driving biological variation, and how the composition of these important ecosystem members may change into the future. Despite this, temporal variation in soil bacteria remains understudied, and the effects of spatial heterogeneity in bacterial communities on the detection of temporal changes is largely unknown. Using 16S rRNA gene amplicon sequencing, we evaluated temporal patterns in soil bacterial communities from indigenous forest and human-impacted sites sampled repeatedly over a 5-year period. Temporal variation appeared to be greater when fewer spatial samples per site were analysed, as well as in human-impacted compared to indigenous sites (P < 0.01 for both). The biggest portion of variation in bacterial community richness and composition was explained by soil physicochemical variables (13–24%) rather than spatial distance or sampling time (<1%). These results highlight the importance of adequate spatiotemporal replication when sampling soil communities for environmental monitoring, and the importance of conducting temporal research across a wide variety of land uses. This will ensure we have a true understanding of how bacterial communities change over space and time; the work presented here provides important considerations for how such research should be designed. [ABSTRACT FROM AUTHOR]

Estimates of historical disturbance patterns are essential to guide forest management aimed at ensuring the sustainability of ecosystem functions and biodiversity. However, quantitative estimates of various disturbance characteristics required in management applications are rare in longer‐term historical studies. Thus, our objectives were to (1) quantify past disturbance severity, patch size, and stand proportion disturbed and (2) test for temporal and subregional differences in these characteristics. We developed a comprehensive dendrochronological method to evaluate an approximately two‐century‐long disturbance record in the remaining Central and Eastern European primary mountain spruce forests, where wind and bark beetles are the predominant disturbance agents. We used an unprecedented large‐scale nested design data set of 541 plots located within 44 stands and 6 subregions. To quantify individual disturbance events, we used tree‐ring proxies, which were aggregated at plot and stand levels by smoothing and detecting peaks in their distributions. The spatial aggregation of disturbance events was used to estimate patch sizes. Data exhibited continuous gradients from low‐ to high‐severity and small‐ to large‐size disturbance events. In addition to the importance of small disturbance events, moderate‐scale (25–75% of the stand disturbed, >10 ha patch size) and moderate‐severity (25–75% of canopy disturbed) events were also common. Moderate disturbances represented more than 50% of the total disturbed area and their rotation periods ranged from one to several hundred years, which is within the lifespan of local tree species. Disturbance severities differed among subregions, whereas the stand proportion disturbed varied significantly over time. This indicates partially independent variations among disturbance characteristics. Our quantitative estimates of disturbance severity, patch size, stand proportion disturbed, and associated rotation periods provide rigorous baseline data for future ecological research, decisions within biodiversity conservation, and silviculture intended to maintain native biodiversity and ecosystem functions. These results highlight a need for sufficiently large and adequately connected networks of strict reserves, more complex silvicultural treatments that emulate the natural disturbance spectrum in harvest rotation times, sizes, and intensities, and higher levels of tree and structural legacy retention. [ABSTRACT FROM AUTHOR]

Backgrounds: There are growing concerns regarding the restoration of karst rocky desertification (KRD) areas. However, the soil conditions and its residing microorganisms, which are essential for the plants, remain largely unclear. Methods: We studied soil characteristics and microbial communities in natural forests (non-KRD) and shrubs with eroded soil and surface soil run-off, using Illumina Miseq sequencing. Results: Our results showed that despite KRD reduced soil fertility and altered microbial community structures, microbial diversity did not diminish. Interestingly, bacterial OTU richness and diversity were greater in the KRD areas than in the non-KRD areas, which had relatively greater plant density and diversity. Fungal OTU richness and diversity remained unchanged by KRD. Although the KRD areas had been clear-cut and trees were mostly absent, ectomycorrhizal fungi did not differ in diversity and relative abundance between the two land types, indicating that the KRD shrubs hosted surprisingly diverse and abundant ectomycorrhizal fungi. Conclusions: Our results highlight the highly diverse microbes under environmental and anthropogenic stresses in KRD areas. Despite the fact that degraded soil properties and an altered microbial community structure remain, KRD did not erode ectomycorrhizal fungal species richness, which is crucial in the revegetation of trees in KRD areas. [ABSTRACT FROM AUTHOR]

The biosemiotic complexity of acoustic communities in the primary forests of Ulu Temburong (Brunei, Borneo) and Yasunì (Ecuador, Amazon) was investigated with continuous 24-h recordings, using the acoustic signature and multiscale approach of ecoacoustic events and their emergent fractal dimensions. The 3D recordings used for the analysis were collected in undisturbed primary equatorial forests under the scope of the project, Fragments of Extinction, which produces 3D sound portraits with the highest definition possible using current technologies – a perfect dataset on which to perform a multiscale qualitative analysis. The ecoacoustic events (EEs) detected by a combination of the Acoustic Complexity Indices, ACIft, ACIft evenness, and ACItf evenness, and its fractal dimension were developed according to a biosemiotics approach in which the ecofield theory states that EE functions like a species-specific carrier of meaning. EEs, extracted according to 10 levels of temporal resolution, from 1 to 360 s, confirm the hypothesis that these acoustic communities have an internal complexity that responds to a fractal structure (fractal dimension D of Ulu Temburong D = 1.33 versus Yasunì D = 1.31). Yasunì was richer in EEs, with a higher coefficient of variation of hourly fractal dimension (Yasunì: D = 6.16 versus Ulu Temburong: D = 2.66). This methodology opens up promising new perspectives in the acoustic assessment of habitat quality and monitoring landscape modification. It also confirms the great potential of the biosemiotics approach in converting acoustic frequencies into ecoacoustic events through encoding procedures that mimic potential species-specific interpretations of the sonic environment. [ABSTRACT FROM AUTHOR]

Accurate cost information is needed to assess the trade-offs in land management choices for policy and markets to effectively scale forest conservation impact. Choice of valuation method can affect value estimates of the costs associated with forest conservation for heterogenous rural households in poorly functioning markets. We present empirical evidence on the divergence in measures between a market price and contingent valuation estimate for costs of local forest access restrictions from household surveys deploying quantitative valuation methods, conducted in two forest communities in the Democratic Republic of Congo. Household demographic characteristics and attitudes of the household on forest use significantly influence required levels of compensation to participate in forest protection. Quantitative knowledge of such costs can help in the design of efficient and effective policies to protect primary forests aimed at reducing the drivers of deforestation. • Accurate valuation of opportunity costs is critical to designing effective policy to incentivize forest conservation. • Where markets do not function well, financial prices vastly underestimate the total economic value of forest protection. • \The financial value of local forest resources was greater for high-income households than low-income households. • Forest goods contributed a greater proportion of total income for low-income households than for high income households. • Incentives for forest conservation must offset the welfare (economic) loss to incentivize household participation. [ABSTRACT FROM AUTHOR]

The functional connectivity of the landscape of the biological corridor Manu-Tambopata (MAT) for the years 2004 to 2013 was analyzed, using indicator species for three types of landscape ecosystems: primary forests, aguajales and pacales. Evidence of changes on the level of connectivity was shown, with a reducing trend in the case of primary forests and aguajales and an increasing one in the case of pacales. The methodology and development of this study aims to provide analysis criteria for future similar studies that will help us determine the conditions of connectivity in a landscape of large dimensions and great territorial dynamics such as MAT more precisely. [ABSTRACT FROM AUTHOR]

Highlights • Downed wood volume is not consistently higher in old-growth vs. secondary longleaf pine forests. • Old-growth longleaf pine forests have among the lowest wood volumes of any old-growth forest. • Fire- and decay-resistant heartwood appears to be an indicator of old-growth conditions. Abstract Few efforts have been made to quantify the amount and variety of deadwood in frequently burned ecosystems, particularly the longleaf pine (Pinus palustris Mill.) ecosystem of the southeastern United States. Moreover, comparisons of coarse woody debris between old-growth and secondary longleaf pine forests are lacking despite the widely recognized value of deadwood to biodiversity in many forest types. We measured standing and fallen deadwood in three old-growth and four mature (100–125 years-old) secondary forests in two landscapes characterized by either sandy or clayey soils within the historic range of P. palustris. Downed coarse woody debris volume was variable at the old-growth locations, ranging from 2.51 ± 0.79 to 29.10 ± 14.55 m3 per ha, which includes perhaps the lowest values ever reported from any old-growth forest. Factors likely contributing to these low volumes include frequent fire, the low basal area characteristic of this forest type, subtropical climatic conditions of the southeastern Coastal Plain, and large termite populations. The high variability observed among the three old-growth locations probably reflect interactions between fire and other disturbances (e.g., wind damage). The old-growth location on sandy soils had significantly higher coarse woody debris volume and deadwood variety (e.g., diameter increments, posture, tree genera and decay classes) than secondary forests sampled nearby. Highly resinous heartwood is a significant indicator of old-growth conditions relative to secondary locations, appearing to accumulate as a persistent fraction of the deadwood pool over time. [ABSTRACT FROM AUTHOR]

In the northeastern region of the Brazilian state of Pará, approximately 90% of the forested areas are secondary forests. Secondary forests are interesting areas for floristic studies aimed at determining the effects that clear-cutting has on bryophyte communities. The aim of this study was to compare upland forests at different successional stages and the various strata of host trees, in terms of the bryophyte species composition. Bryophyte specimens were collected between August 2005 and September 2006 from host trees in primary and secondary forests of different ages and of different heights, within the municipality of Capitão Poço, in the state of Pará. The vertical distribution of bryophytes was evaluated in 15 host trees within the primary forest. We identified a total of 99 bryophyte species: 33 mosses and 66 liverworts. The dominant family was Lejeuneaceae, with 56 species. Most of the species (n = 60) had a neotropical distribution, and 3 species were endemic to Brazil. Cololejeunea minutissima var. myriocarpa (Nees & Mont.) R.M.Schust., Pycnolejeunea papillosa X.-L. He, Radula mammosa Spruce and Verdoornianthus marsupiifolius (Spruce) Gradst. represent new records for the state of Pará. In the successional forests evaluated, we identified 78 species, most of which (n = 38) occurred in primary forest. On the host tree trunks evaluated in the primary forest, we observed 31 species occurring at heights ranging from 2 m to 20 m. Despite the fact that secondary forests account for such a large proportion of the forested areas in Capitão Poço, we found that the bryoflora was relatively rich, comprising 31% of the species recorded for the state. The fact that 40% of the species recorded occurred exclusively in the secondary forests and the fact that 45.5% of the species recorded in primary forest occurred within the 2-20 m height range show the importance of studies focusing on bryophytes in secondary forests and in the upper strata of host trees in primary forests.

Understory vegetation influences several ecosystem services and functions of European beech (Fagus sylvatica L.) forests. Despite this knowledge on the importance of understory vegetation, it is still difficult to measure its three-dimensional characteristics in a quantitative manner. With the recent advancements in terrestrial laser scanning (TLS), we now have the means to analyze detailed spatial patterns of forests. Here, we present a new measure to quantify understory complexity. We tested the approach for different management types, ranging from traditionally and alternatively managed forests and national parks in Germany to primary forests of Eastern Europe and the Ukraine, as well as on an inventory site with more detailed understory reference data. The understory complexity index (UCI) was derived from point clouds from single scans and tested for its relationship with forest management and conventional inventory data. Our results show that advanced tree regeneration is a strong driver of the UCI. Furthermore, the newly developed index successfully measured understory complexity of differently managed beech stands and was able to distinguish scanning positions located on and away from skid-trails in managed stands. The approach enables a deeper understanding of the complexity of understory structures of forests and their drivers and dependents.

Lugares susceptibles a perturbaciones naturales o antrópicas pueden recuperar la cobertura boscosa. La sucesión tropical puede ser afectada por factores tales como perturbaciones, distancia al bosque original, topografía y clima local. Estos factores determinan la composición de especies y la tasa de recuperación de los sitios. Se estudió la sucesión en suelos que habían sido usados para el establecimiento de pasturas ganaderas por varias décadas en la Región Porce de Colombia (bosques Colombianos de los Andes). Se midieron un total de veinticinco parcelas, incluyendo nueve parcelas (20x50m) en bosques primarios y dieciséis (20x25m) en bosques secundarios. Se midieron todos los árboles con un diámetro ≥1.0cm. Se analizó la densidad, área basal, biomasa aérea y riqueza de especies, en un bosque con un proceso sucesional de ca. 43 años y en un bosque primario. Las edades de los bosques secundarios fueron obtenidas en estudios previos usando la datación con carbono catorce (C14), fotografías aéreas y el análisis de imágenes de satélite de alta resolución (entre 7 y >43 años). En total, 1 143 y 1 766 individuos se midieron en bosque primario y secundario, respectivamente. El área basal (5.7 a 85.4m²ha-1), la biomasa aérea (19.1 a 1 011.5 t ha-1) y la riqueza de especies (4 a 69) aumentaron directamente con la edad de los sitios, mientras que la densidad de árboles disminuyó (3 180 a 590). Las distribuciones diamétricas fueron en J-invertida para los bosques primarios y unimodal para los secundarios. Tres especies de palmas fueron abundantes y exclusivas de bosques secundarios viejos y bosques primarios: Oenocarpus mapora, Euterpe precatoria y Oenocarpus bataua. Cohortes de estas palmas aparecieron después de perturbaciones del bosque. La recuperación de la estructura de los bosques secundarios en más de 43 años de sucesión fue 40% e indica que varios factores están interactuando y afectando la sucesión de los bosques en el área (e.g. agricultura, ganadería extensiva, minería, etc.).Structural recovering in Andean successional forests from Porce (Antioquia, Colombia). Places subjected to natural or human disturbance can recover forest through an ecological process called secondary succession. Tropical succession is affected by factors such as disturbances, distance from original forest, surface configuration and local climate. These factors determine the composition of species and the time trend of the succession itself. We studied succession in soils used for cattle ranching over various decades in the Porce Region of Colombia (Andean Colombian forests). A set of twenty five permanent plots was measured, including nine plots (20x50m) in primary forests and sixteen (20x25m) in secondary forests. All trees with diameter ≥1.0cm were measured. We analyzed stem density, basal area, above-ground biomass and species richness, in a successional process of ca. 43 years, and in primary forests. The secondary forests’ age was estimated in previous studies, using radiocarbon dating, aerial photographs and a high-resolution satellite image analysis (7 to >43 years). In total, 1 143 and 1 766 stems were measured in primary and secondary forests, respectively. Basal area (5.7 to 85.4m²ha-1), above-ground biomass (19.1 to 1 011.5 t ha-1) and species richness (4 to 69) directly increased with site age, while steam density decreased (3 180 to 590). Diametric distributions were "J-inverted" for primary forests and even-aged size-class structures for secondary forests. Three species of palms were abundant and exclusive in old secondary forests and primary forests: Oenocarpus mapora, Euterpe precatoria and Oenocarpus bataua. These palms happened in cohorts after forest disturbances. Secondary forest structure was 40% in more than 43 years of forest succession and indicate that many factors are interacting and affecting the forests succession in the area (e.g. agriculture, cattle ranching, mining, etc.). Rev. Biol. Trop. 58 (1): 427-445. Epub 2010 March 01.

• An ecological comparison of near-natural forests and various tree plantations. • Near-natural forests had high taxonomic, functional, and phylogenetic diversity. • Plantations of non-native tree species performed poorly in most respects. • Among the plantations, Populus alba plantations proved to be the most valuable. • The current large extent of Pinus and Robinia plantations is ecologically undesirable. While near-natural forest stands are dramatically diminishing, monoculture tree plantations are rapidly spreading globally, including the eastern part of Central Europe. Tree plantations are regarded as simplified and species-poor ecosystems, but their functional and phylogenetic diversity and ecological value are still mostly unknown. In the present study, we investigated near-natural poplar forests and the three most common tree plantation types (native deciduous Populus alba , non-native evergreen Pinus nigra , and non-native deciduous Robinia pseudoacacia plantations) in the Kiskunság Sand Ridge, central Hungary. Our aim was to find out how different the species composition of the studied habitats is, how taxonomic, functional, and phylogenetic diversity vary among the four habitat types (i.e., near-natural forests and three types of plantations), and what the ecological value of the studied habitats is. We found that the four habitat types had significantly different species compositions. Although each habitat contained some diagnostic species, near-natural forests had the highest number of diagnostic species. While many of the diagnostic species of near-natural forests were native shrubs, tree plantations had many weeds and non-native herbs as diagnostic species. Near-natural forests had the highest per plot richness of native species and the lowest richness of non-natives. Shannon diversity, functional diversity and phylogenetic diversity were higher in the near-natural forests and two types of plantations (Populus and Pinus) compared to Robinia plantations. Based on naturalness indicator values, near-natural forests were the least degraded and Robinia plantations were the most degraded. Near-natural forests contained the most species of high conservation importance. Overall, near-natural forests proved to be much more valuable from an ecological and conservation perspective than any of the studied plantations; conservation and restoration programs should therefore focus on this type of habitat. Among the plantations, Populus alba plantations are the best substitute option in most respects, although they harbored a relatively high number of non-native species. We suggest that the native Populus alba should be preferred to non-native tree species when plantations are established. In addition, decreasing the extent of Pinus and Robinia plantations is essential on the long run if we aim to maintain the ecological integrity of the region. [ABSTRACT FROM AUTHOR]

La sucesión secundaria en las regiones tropicales tiende a variar de una localidad a otra debido, entre muchos factores, al tipo e intensidad de la perturbación, la distancia al bosque original, la fauna existente, la topografía y el clima local, los cuales determinan la composición florística y la velocidad con la que la sucesión avanza. En esta investigación se estudió la dinámica del proceso sucesional en suelos dedicados previamente a la ganadería en el cañón del río Porce (Antioquia), Colombia. Se muestrearon en total 25 parcelas, incluyendo 9 (20 x 50 m) en bosques primarios y 16 (20 x 25 m) en bosques secundarios; para éstos últimos la edad fue estimada en estudios previos usando datación por radiocarbono (C14), fotografías aéreas y una imagen de satélite de alta resolución. Se calculó la diversidad y la composición florística en los bosques secundarios, y los resultados se compararon con los obtenidos en bosques primarios cercanos. Se registraron 220 y 197 especies en los bosques primarios y secundarios, respectivamente. Las dos coberturas presentaron composición florística diferente sugiriendo alta diversidad beta. Análisis multivariados mostraron un gradiente sucesional definido y una alta correlación entre la composición florística y las variables ambientales. No obstante, en el área de estudio se presenta un proceso sucesional degradado como consecuencia del uso previo de la tierra. El índice de valor de importancia indica que en los bosques primarios la especie más importante fue Anacardium excelsum (Anacardiaceae) y en los secundarios Vismia baccifera (Hyperiaceae). Además, este índice y la presencia y ausencia de las especies en cada fase de desarrollo, sugieren la existencia de un gradiente sucesional que se ajusta tanto a la teoría clásica clementsiana de relevo florístico, como a la de composición florística original. El ajuste de ciertas especies a dos de las teorías sucesionales existentes, sugieren que el proceso sucesional es diferente y de complejidad variable según las características ecofisiológicas de las especies involucradas y las del ecosistema que se está regenerando.Some studies indicate that tropical secondary succession is to be affected by factors such as disturbances, distance from original forests, surface configuration, and local climate, determining not only the composition of species but also the time trend of the succession itself. This study seeks to understand the dynamics of successional processes in soils devoted to cattle ranching over various decades in the Porce region of Colombia. A set of 25 permanent plots was measured, including 9 plots (20 x 50 m) in primary forests and 16 (20 x 25m) in secondary forests. The age of secondary forests was estimated in previous studies, using radiocarbondating, aerial photographs and a high-resolution satellite image. Both diversity and composition of species in secondary forests were calculated, and the results were compared against those obtained from natural forests located in the same study area. In total, 220 and 197 species were identified in primary and secondary forests, respectively. The floristic composition for both vegetation types was significantly different, indicating a high Beta diversity. Multivariate analyses suggest the existence of a well-defined successional gradient, and a high correlation between composition of species and some environmental variables as well. However, the study area is characterized by a successional process highly degraded, which seems to be the obvious consequence of the previous land use. The importance value index indicates that Anacardium excelsum (Anacardiaceae) and Vismia baccifera (Hypericaceae) tend to be the dominant species in primary and secondary forests, respectively. The importance value index and the presence or absence of species show that the ecological behavior of various species of the successional gradient may be explained by both the relay and original floristic composition. This finding might be the result of ecophysiological strategies of the species and environmental attributes of the ecosystems, which are experiencing slow but natural recovery.

Soil organic carbon (SOC) represents the major soil reservoir in the terrestrial ecosystems. The deforestation and the intensive agriculture use increases the CO2 emissions to the atmosphere, promoting the processes related with global climatic change. The objective of this work was to measure the content of SOC under different vegetation covers at the Mololoa basin in Nayarit State, Mexico. Using geomorphological regionalization and land use maps by geographic information system, 27 sampling sites were established. For each soil sampling of 30 cm depth, with three replicates in each site. The samples obtained were analyzed for bulk density, the organic carbon concentration and the carbon content within the top 30 cm depth. The was calculated oak forest had the highest SOC content (140 Mg ha-1). The SOC contents under grassland, secondary vegetation, pine forest, crop land and tropical forest were similar among them (99, 83, 73, 53 and 53 Mg ha-1, respectively). The land cover with higher SOC content were oak forest for its higher SOC concentration and the crop land for its higher area occupied within the studied basin. [ABSTRACT FROM AUTHOR]

Compared Pedological Characteristics of Termite Mounds under Primary Forests of Yangambi Platform in Congolese Central Basin. Some pedological characteristics of five identified termite mounds under primary forests of Yangambi platform in congolese central basin are compared with those of host soil series. Five termite mounds are conical shaped (tcn) of Noditermes cristifrons Sjöst., hat-shaped (tch) of Cubitermes speciosus Sjöst., semi-arboricolous (tsa) of Apilitermes longiceps Sjöst., dome-shaped (tdo) of Thoracotermes macrothorax Sjöst. and hill-shaped (tco) of Macrotermes muellai Sjöst. Four host soil series are Yambaw (Y0), Yangambi (Y1), Yakonde (Y2) and Yambeli (YL); they are more colonized by termite mounds and more farmed by peasants of Yangambi region. The achieved results show that termite mounds are more fertile than host soil series. Among five identified termite mounds, three are interesting as sources of fertilizers: tsa, tch and tdo. Particularly for the tco, analytical values are comparable to those of the host soil series. For practical applications, tsa is identified as better source of soil fertility for rice sown to vegetables and tdo for amaranth. Combined with dried peanut straw, tcn obtained best results on amaranth. Termite mounds are abundant in rainforest of Yangambi platform and their fertility is high compared to that of host soil series. They may be of interest as sources of soil fertility at small scale vegetables growing.

• Below a maximum thermal threshold, juvenile tree growth increased with temperature • Spruce was markedly more sensitive to water stress relative to beech • Spruce growth was elevated in species diverse stands • Growth rates in juvenile trees have increased over time since 1750 • Sustained warming that exceeds physiological optima may constrain future growth Global change outcomes for forests will be strongly influenced by the demography of juvenile trees. We used data from an extensive network of forest inventory plots in Europe to quantify relationships between climate factors and growth rates in sapling trees for two ecologically dominant species, Norway spruce and European beech. We fitted nonlinear regression models with annual radial growth measurements from ∼17,500 trees in primary forests to investigate the sensitivity of individuals to temperature and measures of water supply. We controlled for multiple, potentially confounding factors, including ontogeny, resource competition and the deposition of anthropogenic nitrogen and sulphur. The growth potential of spruce was markedly elevated relative to beech, reflecting species-specific relationships with environmental drivers. Declining water availability more strongly limited productivity in spruce, while beech was notably tolerant of observed levels of moisture limitation. Warming promoted growth in both species, but growing season temperatures that exceeded thermally optimum conditions constrained wood production. We identified long-term positive trends in reconstructed annual rates of juvenile tree growth since the early 19th century, likely driven by industrial-era warming. However, our findings suggest that sustained warming and more prevalent future drought may ultimately inhibit growth due to thermal thresholds and a differential tolerance of water stress. Consequently, global change factors may be expected to affect future species abundance patterns, biomass production, and the carbon sink capacity of forests in Europe. [ABSTRACT FROM AUTHOR]