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After canopy removing disturbance, recalcitrant understory shrubs can rapidly occupy the forest understory to the detriment of tree regeneration and growth. The expansion of recalcitrant species has been documented following stand replacing disturbances, such as fire and timber harvest. However, there is little information on how these species respond to much smaller canopy gaps created by the senescence and (or) death of single or groups of canopy trees. In this study, we determined the response of Labrador tea (Rhododendron groenlandicum Oeder.), a recalcitrant ericaceous shrub, to canopy gaps in a late-successional boreal forest in northwestern Ontario, Canada. We evaluated functional traits related to the morphology and regeneration strategy of this plant to elucidate the mechanism of gap filling. We found that R. groenlandicum abundance and vigor were greater at the center of treefall gaps than in gap edges or the forest understory due to aggressive sprouting from buried clonal bud banks. Layering was higher in canopy gaps than in the understory. The composition of ground cover and rooting substrate was more influential on the adventitious rooting of the layered stems than increased light availability in gaps. We found a strong response of R. groenlandicum to small canopy openings, suggesting that the species can form recalcitrant understory layers even in the absence of stand replacing disturbance. [ABSTRACT FROM AUTHOR]

The use of prescribed burns to suppress woody invasive species like common buckthorn (Rhamnus cathartica) in temperate deciduous forests is often limited by fine fuel availability. This is particularly problematic in the period following mechanical removal of buckthorn, when fire has the greatest probability of preventing buckthorn from re-establishing dominance through remaining small individuals, resprouts, or seeds. Here, we test whether revegetating by seeding C3 grasses and forbs enhances fine fuel availability and subsequent spread and impact of prescribed burns in two semi-open forests (8–24% tree canopy light transmission) in Minnesota. We found seeding increased cover of grass litter by more than 12-fold and decreased bare ground by 73%. Consequently, seeded areas enhanced fire spread by 85% and resulted in a three-fold increase in the proportion of wood pyrometers fully consumed. One year after burning, seeded plots had 72% less woody cover compared to adjacent unseeded plots, and burned subplots had 33% less woody cover compared to adjacent subplots that were not burned. Our findings support the use of herbaceous seeding (particularly of Elymus grasses) in buckthorn removal projects. The positive effects of seeding on burn performance via increased fine fuel quantity outweighed potential negative effects of understory phenology on fuel moisture content and flammability. Thus, a combined approach of seeding and burning is likely to offer enhanced control of small buckthorn stems compared to either passive restoration or seeding alone. [ABSTRACT FROM AUTHOR]

Non-native, invasive plants are increasingly common in Eastern North American forests, but their impact on soil fungi remains unclear. We used DNA metabarcoding to investigate the effects of nativity, plant mycorrhizal type and soil factors on root-associated fungal communities. We focused on understory woody plants in a deciduous forest tract in central New York state, and included three plant types, invasive arbuscular mycorrhizal (AM), native AM, and native ectomycorrhizal (EM), each represented by 3–5 species. We found lower fungal operational taxonomic unit (OTU) diversity in EM than AM plants, but no OTU diversity difference between native and invasive AM species. Pathogen OTU richness and relative abundance were not distinct between plant types. OTU composition was influenced by host mycorrhizal type and by AM plant nativity, with mycorrhizal fungi being important drivers in both cases. The relationships of soil characteristics (e.g., pH) with OTU composition were independent of plant nativity and mycorrhizal type. Specific root length of native AM species was lower than that of invasive AM plants, while EM plants were intermediate. Irrespective of plant type, OTU composition was distinct among plant species, particularly in fungal communities associated with the invader Rhamnus cathartica. These results suggest that invasive AM plants may shift fungal composition relative to native AM and EM plants, with potential long-term consequences for soil biodiversity. [ABSTRACT FROM AUTHOR]

Logging in mature stands where part of the forest is harvested in one or several cuts and part is retained (clearcutting and alternate strip cutting) results in the formation of an ecotone complex (EC), which includes a forest (F) zone, a forest edge (FE) as a transition from the forest to the clear-cut under the canopy, a clear-cut edge (CE) as a transition from the forest to the clear-cut outside of the canopy, and the clear-cut proper (C). The composition and structure of ground vegetation and natural regeneration of woody species (Pinus sylvestris L., Picea abies (L.) H. Karst., Betula sp., Populus tremula L., Sorbus aucuparia L., and Juniperus communis L.) were studied in a bilberry pine forest–clear-cut ecotone complex 12–15 years after stand removal. Specific structural features of ground vegetation and undergrowth (including tree regeneration) were observed in each of the four zones of the ecotone complex formed after logging of the mature forest. A typical forest habitat (zone F) showed a minimum number of young regeneration of Pinus sylvestris, Picea abies, Betula sp., Populus tremula, and Sorbus aucuparia and the highest abundance of the lingonberry V. vitis-idaea L. and bilberry Vaccinium myrtillus L. with a maximum height and a maximum yield of bilberry plants. The amount of tree regeneration in the FE zone was much the same as in the F zone. The projective cover, maximum shoot height, and yield of bilberry and the maximum shoot height of lingonberry in the FE zone were significantly lower than in the F zone. The transitional zone on the clear-cut side (CE) and the clear-cut proper (C) strikingly differed from the forest (F and FE) zones of the ecotone complex by a greater number of deciduous and pine regeneration and a low abundance of dwarf shrubs. The clear-cut proper (C) differed from the CE zone by a higher abundance of grasses and forbs and an established tree regeneration layer composed of pine, birch, and aspen. [ABSTRACT FROM AUTHOR]

Seasonal forests are characterized by seasonal dynamics that influence the growth and ecophysiology of forest species. Erythroxylum pauferrense is an understory species endemic to the Northeastern region of Brazil, with a distribution limited to Paraíba, Brazil. In this study, how the physiological characteristics of E. pauferrense vary in response to seasonal changes in an open ombrophilous forest of the Brazilian Atlantic Forest was investigated. Precipitation, air and soil temperature, and leaf area index were monitored and correlated with gas exchange, chlorophyll fluorescence, chlorophyll indices, and leaf morphofunctional attributes. The results show that E. pauferrense exhibits ecophysiological plasticity, adjusting its photosynthesis rates, stomatal conductance, and water use efficiency according to seasonal changes. During the rainy season, photosynthesis and stomatal conductance were higher than in the dry season, indicating more excellent photosynthetic activity due to increased water availability. Water use efficiency varied, with more efficient use in the dry season, which is crucial for survival in conditions of low water availability. Thus, this study contributes to understanding the ecology of endemic understory species in seasonal tropical forests, such as Erythroxylum pauferrense. [ABSTRACT FROM AUTHOR]

To investigate the impact of topography on understory biomass, this study employed a nested design and conducted surveys in the Northeast China Tiger and Leopard National Park, involving a total of 138 plots within closed forests, comprising 1 685 plant quadrats. The analysis of topographical effect on understory biomass was carried out using nested analysis of variance and an ordinal logistic regression model. The results were as follows: (1) Among different slope positions, the understory biomass in valleys was higher than on upper slopes, and the footslopes where the understory biomass was the lowest (P<0.01). The understory biomass on shady slopes was lower than on sunny slopes and flats (P<0.01), with no significant difference between the latter two. In terms of different slopes, the understory biomass on steep slopes was higher than on flats, and flats had higher biomass than gentle slopes (P<0.01). (2) There was a significant interaction between slope position and slope aspect. The understory biomass was the highest on flats at the footslopes, flats on upper slopes, upper slopes and sunny slopes, and in valleys among all slope positions. There was no significant difference in understory biomass among shady slopes at the footslopes, sunny slopes at the footslopes, and shady slopes on upper slopes. (3) Ordinal logistic regression analysis of the current state of the study area showed that the probability of high or low understory biomass varied across different combinations of altitude, slope position, and slope aspect. Slope position, slope aspect, and slope had significant effects on the understory biomass. Among the three slope positions, the understory biomass was the highest in valleys and the lowest on footslopes. Among the three slopes, steep slopes had the highest understory biomass, while gentle slopes had the lowest. Shady slopes had the lowest understory biomass compared to other slope aspects. (4) Considering the realistic situation of human disturbance and forest grazing, steep slope areas in valleys had the highest probability of high understory biomass. This study can provide important references for accurately estimating the carrying capacity of understory for preys populations of tiger and leopard in Northeast China Tiger and Leopard National Park, thereby offering a scientific basis for the conservation and management of endangered tigers and leopards. [ABSTRACT FROM AUTHOR]

This study aims to reveal the relationships between understory coverage (principally, weed growth) beneath the canopies of Sumatran eucalyptus plantations and L-band backscatter data gathered by the PALSAR-2 Synthetic Aperture Radar (SAR) onboard the ALOS-2 satellite. Statistical analysis in conjunction with in situ measurements of forest structural parameters reveals that the SAR polarization ratio is significantly negatively correlated with understory coverage in forests taller than or equal to 10 m or above 2 years of age. Our field investigations confirm that a decrease in canopy coverage takes place some 2 years after transplanting, which in turn permits increased penetration (decreased attenuation) of microwave signals thereby enabling the SAR to detect changes in understory coverage. In addition, both growth and unmanaged remnants of the understory vegetation in older forests reduce evaporation from the ground, which in turn stabilizes soil-moisture levels throughout the year and allows co-polarized backscatter data (which might otherwise be dominated by soil-moisture changes) to contain significant information on the underlying vegetation. No correlation between the understory and SAR backscatter was recorded in younger forests undergoing programs of intensive weed management. This is presumably because strong canopy and trunk backscatter obscured the response from understory vegetation and because artificial changes were induced in vegetation water content as a result of the application of herbicides which in turn reduced the accuracy of some of our field measurements of understory coverage. This research nevertheless demonstrates an important potential application of active satellite microwave remote sensing. We show that satellite-based L-band SAR can be used as a tool to investigate coverage percentages of understory layers. This synoptic technique reduces the need for repeated field surveys across large areas of forest. It can enhance ecosystem assessment and improve understory coverage estimates in sparse forests and in various types of plantations.

This study contributes to understanding ecological changes in land use following slash-and-burn land clearing. This study aimed to compare the richness and density of plant species and soil fertility in farmland cultivated for one year (1 Y), three years (3 Y), and five years (5 Y) after slash-and-burn, with the conditions in the secondary forest (SF) in Berau Regency of East Kalimantan. Understory plant taxon types, numbers, and soil organic matter were measured in each region using a series of nested plots. The size of each observation plot was 20 x 100 m. Data on understory vegetation composition was collected using 1 x 1 m mini plots at 20 sampling points and divided into five blocks, with a 10 m spacing between sampling points on each property. Understory vegetation species and cover percentage, litter cover percentage, open soil percentage, and soil fertility were measured for each observation plot. The results showed that the land cover percentage increased each year during the 5 years transition from secondary forest to farmland. Furthermore, within the 5 years, there was a change in understory species, particularly the presence of grasses and sedges at 3 and 5 years after the land use change. However, the transition from secondary forest to farmland within 5 years did not alter soil organic matter and total nitrogen.

The response of plant species to the variation in abiotic factors affects the regeneration capacity and, consequently, the structure of the forest community. This study aims to describe the structure of the regenerating stratum in a Brazilian montane rainforest and investigate its relationship with environmental and spatial variables along an altitudinal gradient. Data on the height and diameter at soil height of regenerating individuals and environmental variables were collected from 28 sample units, distributed in seven altitudinal sites. To understand the spatial influence on species distribution, spatial variables (MEMs - Moran’s Eigenvector Maps) were created based on geographic coordinates. Phytosociological parameters were calculated by species. Floristic similarity between the altitudinal quota was determined by the Bray-Curtis index (UPGMA), and the species that characterize each group were determined by the Indicator Species Analysis. Redundancy Analysis (RDA) was performed, and generalized linear models were adjusted to verify the influence of environmental and spatial factors on regenerating vegetation. The species Palicourea sessilis had the highest Importance Value in the regenerating community. Two floristic groups were formed: the highest sites (1420 to 1550 m a.s.l.) were floristically more similar to each other (Group 1) than to the sites in the 1112 to 1391 m elevation range (Group 2). Overall, 11 species were indicators of Group 1 and only one of Group 2. Finally, a pattern of species substitution was verified as a function of abiotic factors. The first two axes of the RDA explained 51.02% of the variation in the floristic composition of the regenerating community. Natural regeneration demonstrated environmental preferences, being influenced by luminosity, abundance in adult components, calcium and sodium contents, plant litter accumulation, altitude, and the spatial structure of the environment. Altitude did not seem to influence the pattern of abundance or richness of regenerating species.

The study represents the results of the forest inventory observations (the data of forest stand, undergrowth, understory, coarse woody debris) based on the reconnaissance stage (the express assessment) of the research on the intensive level polygon “Kivach” (Republic of Karelia) within the implementation of the monitoring framework of the carbon budget in the forests of Russian Federation. We found that within the polygon the old-growth overmature coniferous forest stands dominate: 71% of the test site area is represented by pine stands, 16% – by spruce ones. The blueberry forest type predominates representing 76 and 38% of pine and spruce stands, respectively. The productivity of the studied forest stands is middle: the average quality class of pine stands is II.7, whereas spruce and birch stands have III.0 only. The composition of the undergrowth is dominated by spruce with the average density in range from 0.14 to 1.70 thousand pcs ha-1. Pine undergrowth is most represented in lingonberry and blueberry pine forests. The understory layer is formed by tree species typical of coniferous boreal forests – common mountain ash, gray alder, goat willow, common juniper, and needle hips. Within the polygon the coarse woody debris amount varies widely and its distribution by stock, type (standing and downed deadwood and stumps) and species identity depends on the dominant tree species of the stand and forest site conditions. Despite the old-growth and low-disturbed status, the forest sites of the polygon “Kivach” largely reflect the tree species and typological diversity of the forests in the middle taiga subzone.

Kalikuning is one of the areas that has a diversity of flora. Kalikuning's fertile land helps a variety of plants flourish there. Since there are no people living here, a wide variety of unidentified and underexplored plants can be known. Therefore, more research on the plant diversity is required. The research aims to invent, document, and find out the diversity of the understory (shrubs and herbs) in Kalikuning. This research used survey and exploration methods. The researchers documented shrub and herb species. Based on the results, 28 families consist of 65 species of shrubs and herbs. Those species are flora that have specific characteristics.

Drought may be more frequent in foreseen decades that will threat non-wood forest products (NWFP) in temperate forests. Plants cope with drought by increasing root foraging ability, which may be also impacted by exposure to light spectra (components of wavelengths in three colours of monochronic lights). In this study, three hybrid light spectra were provided by light-emitting diode (LED) in red (wavelength: 13.6% blue, 60.0% green, 26.4% red), green (2.9% blue, 84.6% green, 2.5% red), and blue (5.4% blue, 77.8% green, 16.9% red) lights for culturing potted Aralia elata seedlings in homogeneous (67.5 mg nitrogen [N] to both halves of pot) and heterogeneous (135 mg N to left half of pot) under drought and well-watered conditions. The red light spectrum was the unique illumination environment where height growth was promoted under well-watered condition and root biomass in fertilized patch was enhanced under drought. Compared to blue light spectrum, red light spectrum increased root foraging scale and precision and placement ratio. Red light spectrum also promoted aboveground biomass, but reduced root collar diameter. No interaction was detected between any pairs of factors among drought, light, and soil nutrient pattern. The heterogeneous pattern increased root to shoot biomass ratio with decreased shoot biomass and increased root foraging sensitivity and precision and fine root placement ratio. Drought enlarged the overall foraging scale with no effects on foraging sensitivity or precision. Overall, exposure to red light spectrum had the potential to promote fine root foraging behaviour under drought, but more trails deserve being tested in the future on a wider range of wavelengths. [ABSTRACT FROM AUTHOR]

Forestation is a common measure to control erosion-induced soil and carbon (C) loss, but the effect can vary substantially between different types of forest. Here, we measured event-based runoff, soil, dissolved organic carbon (DOC), particulate organic carbon (POC) and total C loss with runoff plots (20 m × 5 m) in a broad-leaved and a coniferous forest in subtropical China and explored their relationships with rainfall amount, average intensity, maximum 5-min intensity and rainfall erosivity. The broad-leaved forest had a denser canopy but sparse understory vegetation while the coniferous forest had a relatively open canopy but dense understory vegetation. The results showed that runoff, soil, DOC, POC and total C losses were all significantly higher in the broad-leaved forest than the coniferous forest despite the potentially higher canopy interception associated with the greater leaf area index of the broad-leaved forest. The mean runoff in the broad-leaved forest was 3.03 ± 0.20 m3 ha−1 event−1 (mean ± standard error) and 12.49 ± 0.18 m3 ha−1 event−1 in the coniferous forest. The mean soil, DOC, POC and total C loss (kg ha−1 event−1) was 1.12 ± 0.16, 0.045 ± 0.003, 0.118 ± 0.016 and 0.163 ± 0.017, respectively, in the broad-leaved forest and 0.66 ± 0.09, 0.020 ± 0.002, 0.060 ± 0.009 and 0.081 ± 0.010, respectively, in the coniferous forest. Runoff and DOC losses were driven by rainfall in two forests, but the key rainfall characteristic driving soil, POC and total C losses was different in the broad-leaved forest from that in the coniferous forest due to their different understory patterns. Soil, POC and total C losses were mostly driven by rainfall amount in the broad-leaved forest but by EI30 in the conifer forest. Our findings highlight that the response of erosion-induced carbon loss to rainfall characteristics differs between different forest types of the same age but contrasting overstory and understory vegetation covers. Moreover, our study underscores the overlooked significance of understory vegetation in regulating these effects. Thus, we call for the inclusion of understory vegetation in the modeling of soil and carbon erosion in forest ecosystems. [ABSTRACT FROM AUTHOR]

This study contributes to understanding ecological changes in land use following slash-and-burn land clearing. This study aimed to compare the richness and density of plant species and soil fertility in farmland cultivated for one year (1 Y), three years (3 Y), and five years (5 Y) after slash-andburn, with the conditions in the secondary forest (SF) in Berau Regency of East Kalimantan. Understory plant taxon types, numbers, and soil organic matter were measured in each region using a series of nested plots. The size of each observation plot was 20 x 100 m. Data on understory vegetation composition was collected using 1 x 1 m mini plots at 20 sampling points and divided into five blocks, with a 10 m spacing between sampling points on each property. Understory vegetation species and cover percentage, litter cover percentage, open soil percentage, and soil fertility were measured for each observation plot. The results showed that the land cover percentage increased each year during the 5 years transition from secondary forest to farmland. Furthermore, within the 5 years, there was a change in understory species, particularly the presence of grasses and sedges at 3 and 5 years after the land use change. However, the transition from secondary forest to farmland within 5 years did not alter soil organic matter and total nitrogen. [ABSTRACT FROM AUTHOR]

Subtropical forests, recognized for their intricate vertical canopy stratification, exhibit high resistance to extreme drought. However, the response of leaf phenology to drought in the species‐rich understory remains poorly understood. In this study, we constructed a digital camera system, amassing over 360,000 images through a 70% throughfall exclusion experiment, to explore the drought response of understory leaf phenology. The results revealed a significant advancement in understory leaf senescence phenology under drought, with 11.75 and 15.76 days for the start and end of the leaf‐falling event, respectively. Pre‐season temperature primarily regulated leaf development phenology, whereas soil water dominated the variability in leaf senescence phenology. Under drought conditions, temperature sensitivities for the end of leaf emergence decreased from −13.72 to −11.06 days °C−1, with insignificance observed for the start of leaf emergence. Consequently, drought treatment shortened both the length of the growing season (15.69 days) and the peak growth season (9.80 days) for understory plants. Moreover, this study identified diverse responses among intraspecies and interspecies to drought, particularly during the leaf development phase. These findings underscore the pivotal role of water availability in shaping understory phenology patterns, especially in subtropical forests. [ABSTRACT FROM AUTHOR]

Native forests can support wild and domestic herbivores, but their nutritional potential of understory vascular plants is rarely explored. We analysed the composition of understory plant species and their biochemical components to reveal the nutritional potential of forest types (deciduous, evergreen, mixed) and their associated open-lands (e.g. grasslands in forestlands) in Northern Patagonia. We proposed an approach combining our data (e.g. plant composition, occurrence frequency) with bibliographic research (e.g. Scopus database) to develop our findings. Data were evaluated using descriptive statistical analyses and multivariate analyses. This study presents the nutritional values for the 20 pivotal species under examination. The results highlight the significant impact of taxonomic families on nutritional profiles, where the species that presented the most relevant occurrence frequency: the herbs T. officinale (60.4 % of total occurrence frequency-TOF) and T. repens (47.9 % TOF), the graminoid H. lanatus (58 % TOF), and the fern B. penna marina (44.4 % TOF). Multivariate analyses showed that the first two PCA axes explained 76.1 % (p = 0.001) and 10.5 % (p = 1.000) of forest type variation, with ñire forests and open-lands having the highest palatable plant coverage. Biochemical PCA axes explained 52.1 % (p = 0.024) and 22.5 % (p = 0.874) of the variation, distinguishing species by protein content and structural components. The deciduous forests exhibited the highest coverage of palatable plants, while target plants with low palatability and high coverage were predominantly found in evergreen forest types. The confirmed presence of pivotal species across forest types and open-lands underscores its nutritional potential, characterised by highly digestible dry matter, crude protein, highly digestible non-nitrogenous nutrients, and relative feed value. Considering their widespread distribution and nutritional factors, the native and non-native plants merit attention due to their pivotal nutritional potential.

Remnant urban forests, or scattered patches of forest within urban areas, serve as crucial biodiversity reservoirs. Investigating how urban environments influence biodiversity within these forests is essential for enhancing conservation strategies. This study examined data from 15 remnant forest patches in Guiyang, China, to assess the impacts of spatiotemporal urban expansion on species richness and functional traits across different life forms and ontogenetic stages in both interior and edge habitats of these patches. Employing generalized linear regression models, we examined variables including the intensity of urban expansion, road density, type of expansion, compound terrain complexity, and the interplay between urbanization levels and the timeframe of urban development. Our results indicated that increased urban expansion intensity positively affected the species richness of shrubs, yet negatively influenced tree richness. Furthermore, high urbanization levels were associated with lower species richness in adult trees and the species in the sapling and shrub layers with high seed mass traits when the duration of urbanization was prolonged. Additionally, we observed that edge-expansion type urban growth notably increased the risk of losing species with resource-conservation traits compared to leapfrog growth patterns. These outcomes highlight the detrimental effects of intensive urban expansion and edge-expansion growth on the conservation of woody plants, especially those characterized by resource conservation traits. They also draw attention to the delayed impacts of urbanization on plant diversity. In response, we advocate for the reduction of urban expansion intensity and control over edge-expansion growth patterns to protect plant diversity in remnant forests. It is also critical to prioritize the conservation of remnant forest patches located in areas that have undergone extensive urbanization for prolonged periods, as these are particularly vulnerable to biodiversity loss.

The character of restorative forest successions after catastrophic disturbances is largely determined by their initial stage. The natural regeneration of tree and shrub species has been investigated, taking into account the influence of herbaceous vegetation on this process in two clear cut area at the site of the 2017 windfall in near Moscow Region. The type of clear cut area is mixed herbs with predominance of reed grass. The soil-forming rocks are sandy loam and light loam. Accounting for the natural renewal of tree and shrub species and soil vegetation cover was carried out on circular test plots with an area of 10 m2 , located at different distances from the edges. 102 species of herbs were found. Clearings differ in the species composition of herbaceous vegetation. The Jaccard similarity index was 37.3 %. This difference is due to the presence of rare species, the most represented species are found in both clear cut area. In clear cut area No. 1, 17 species of trees and shrubs were noted, and in clear cut area No. 2, 13 species. Scots pine (Pinus sylvestris L.), silver (Betula pendula Roth) and moor (Betula pubescens Ehrh.) birch, and aspen (Populus tremula L.) dominated in both clearings. Successful regeneration of pine trees was noted at a distance of no more than 50 m from the forest wall. Small-leaved species are found throughout in the clear cut area. The amount of natural reforestation of pine significantly exceeds the amount of birch and aspen, at the same time, pine is much inferior to these species in height. Among herbaceous plants, the renewal of pine is most hindered by the reed grass (Calamagrostis arundinacea (L) Roth.), and among deciduous species – aspen. For the successful formation of pine stands, it is recommended to carry out thinning.

Tree monocultures constitute an increasing fraction of the global tree cover and are the dominant tree‐growing strategy of forest landscape restoration commitments. Their advantages to produce timber are well known, but their value for biodiversity is highly controversial and context dependent. Therefore, understanding whether, and in which conditions, they can harbor native species regeneration is crucial. Here, we conducted meta‐analyses based on a global survey of the literature and on a database created with local, unpublished studies throughout Brazil to evaluate the regeneration potential of native species under tree monocultures and the way management influences this regeneration. Native woody species regeneration under tree monocultures harbors a substantial fraction of the diversity (on average 40% and 68% in the global and Brazilian surveys, respectively) and abundance (on average 25% and 60% in the global and Brazilian surveys, respectively) of regeneration observed in natural forests. Plantations with longer rotation lengths, composed of native tree species, and located adjacent to forest remnants harbor more species. Pine plantations harbor more native individuals than eucalypt plantations, and the abundance of regenerating trees is higher in sites with higher mean temperatures. Species–area curves revealed that the number of woody species under pine and eucalypt plantations in Brazil is 606 and 598 species, respectively, over an aggregated sampled area of ca. 12 ha. We highlight that the understory of tree monocultures can harbor a considerable diversity of regenerating native species at the landscape and regional scales, but this diversity strongly depends on management. Long‐rotation length and favorable location are key factors for woody regeneration success under tropical tree monocultures. Therefore, tree monocultures can play a role in forest landscape restoration and conservation, but only if they are planned and managed for achieving this purpose. [ABSTRACT FROM AUTHOR]

The paper investigates the natural regeneration of downed deadwood in the Janj primeval forest. The old-growth forest is located in the southwestern part of the Republic of Srpska, which is dominated by dolomite geological base on which cambial soils were formed. The climate is perhumid and mountainous and the plantation belongs to the Piceo-Abieti-Fagetum community. The hectare contains 517 live trees with a total basal area of 53.0 m2/ha and a volume of 876 m3/ha. Twenty six downed deadwoods classified into three different degrees of decay were included in the study, where fir and spruce seedlings were found to be predominant and beech seedlings were rarely represented. The first degree of decay includes 7 (26.9 %), the second 8 (30.7 %), and the third 11 (42.3 %). The total volume of deadwood is 110.82 m3/ha with an average volume per tree of 4.2 m3/ha. The total number of seedlings on fallen dead trees is 836 seedlings (Abies alba – 89.59 %, Picea abies – 10.17 %, Fagus silvatica – 0.24 %). Fir seedlings are found on 25 fallen trees, spruce on 18 fallen trees, and beech on 2 fallen trees. Regarding quality, on average fir seedlings are better than spruce seedlings, but both species show a lot of senescence and very small size of current height increment. Most seedlings belong to the third quality class (fir – 46.2 %, spruce – 61.1 %), followed by second class (fir – 34.6 %, spruce – 22.2 %) and third class (fir – 19.2 %, spruce – 16.7 %). The total number of seedlings was found to have a statistically significant difference in the amount of downed deadwood depending on the degree of decay, and the number of seedlings depended on the degree of tree decay. The number of seedlings increased with increasing volume and length of rotten trees. Acknowledgеments: This article is the result of the project “Аdaptive management of Natural Resource of the Republic of Srpska”. We would like to thank the Ministry of Scientific and Technological Development, Higher Education and Information Society of the Republic of Srpska for their support in the realization of the project. For citation: Govedar Z., Prokhorova N., Babić V., Dukić V., Kanjevac B., Bilić S. Natural Regeneration on Deadwood in the Primeval Forest Janj. Lesnoy Zhurnal = Russian Forestry Journal, 2023, no. 5, pp. 90–102. (In Russ.). https://doi.org/10.37482/0536-1036-2023-5-90-102

A combination of forest thinning followed by prescribed burning is widely applied in the western United States to increase ecosystem resistance and resilience to disturbances. Understory plant community responses may be driven by both management treatments and climatic factors. Thus, responses to treatments during a 20‐year megadrought have implications for the role of management in fostering adaptive capacity to climate change.We used a network of five sites (600 plots) spanning an environmental gradient in ponderosa pine (Pinus ponderosa) forests of the American Southwest, an ecosystem that is broadly distributed and actively managed throughout the western United States. We used repeated long‐term monitoring data to quantify plant community responses to treatment 1–5‐, 6–10‐ and >10‐year post‐implementation. Specifically, we focussed on the effects of treatment and abiotic conditions on native and non‐native plant cover and species richness and the proportion of native species with northern (cool‐mesic) biogeographic affinities.Overall, thinning and prescribed burning nearly doubled native cover and increased native species richness by about 50% relative to untreated controls. These effects persisted for over a decade after treatment, even under the influence of significant and persistent drought. Cover and richness were also greater on intermediate to wet sites. Finally, native species with northern biogeographic affinities were reduced for up to 5 years after treatment relative to those with southern (warm‐xeric) affinities, and in dry years, indicating that both management and interannual climate variability may foster shifts to plant communities that are more resilient to a warming climate.Synthesis and applications. In ponderosa pine forests of the American Southwest, tree thinning followed by prescribed burning will generally promote restoration goals of increasing resilience to climate change by enhancing the diversity and abundance of native understory plant species, even during a persistent 20‐year megadrought. [ABSTRACT FROM AUTHOR]

Studying functional trait diversity can provide crucial clues about the adaptive survival strategies of regional plant species pool. Despite large-scale trait datasets available worldwide, the plant trait data from many biodiversity hotpot regions, like the Himalaya is still scarce. In this study, we aimed to investigate the plant functional traits and aboveground biomass of understory herbaceous vegetation in temperate forests of Overa-Aru wildlife sanctuary of Kashmir Himalaya. We also investigate how these functional traits correlate and what is the magnitude of trait-biomass relationship across the herbaceous species pool. For this, we conducted field sampling and measured leaf functional traits and aboveground biomass of 38 plant species in the study region during peak growing season (July–August) in the year 2021. The results revealed a significant interspecific trait variability among the species studied. We observed a high variability in leaf size and type spectra of the species, with nanophyll and simple leaf lamina, respectively, the most common types among the species studied. The correlation analysis revealed that plant height was positively correlated with aboveground biomass. The variation partitioning analysis revealed that the plant height explained the maximum fraction of variation in aboveground biomass, while least by specific leaf area. Overall, the findings from the present study provide useful insights in understanding trait-trait relationship and trait-environment interaction at the regional scale and can also help in recognizing adaptive functional traits of plant species that determine plant survival under the changing climate in this Himalayan region. [ABSTRACT FROM AUTHOR]

Geonoma maxima (Poit.) Kunth is an example of a species complex, among many others restricted to Neotropical rain forests, which contribute to their high species diversity. Using environmental, morphological, karyological, and molecular data, we aim to test the taxonomic circumscription of 3 of the 11 G. maxima subspecies defined in the latest taxonomic treatment. We evaluated 217 samples of G. maxima complex from Ducke Reserve in the state of Amazonas, Brazil. Environmental preferences were significant at the 0.1% level. Subspecies maxima occurred in the slope, subsp. chelidonura in the floodplain, and subsp. spixiana in the plateau. Leaf morphology and height were different for each subspecies, but not leaf anatomy. The karyotypes of subspp. chelidonura and maxima were symmetrical with 2n = 28 chromosomes, 16 metacentric and 12 submetacentric. Molecular analysis revealed two groups, one comprised subspp. maxima and chelidonura, and the other formed exclusively by subsp. spixiana. At Ducke Reserve, it is clear that the three subspecies are easily recognizable morphologically and ecologically, and it is likely that they do not interbreed locally. However, if these subspecies are analyzed on a larger geographic scale, it may not be possible to separate them. [ABSTRACT FROM AUTHOR]

Leaf functional traits strongly influence plant growth, reproduction, and survival, which are also associated with ecosystem functions. Understory plants are important components of plantation biodiversity. How plantation type affects the performance of different understory shrubs is still poorly understood. In the present study, to address suitable shrub species for the understory management of mature plantations, three common understory species, including Psychotria rubra, Ilex asprella, and Evodia lepta, were selected to investigate the responses of leaf traits to four plantation types (Acacia auriculiformis, Eucalyptus urophylla, Schima superba, and Pinus massoniana). The results showed that the leaf functional traits of understory shrubs were species‐specific among different plantations. The plantation types significantly influenced the specific leaf area (SLA), leaf N:P ratios, chlorophyll, and starch concentrations of these studied shrubs, which may have contributed to the microclimate rather than the soil nitrogen availability originating from different plantations in P‐limited ecosystems. For individual shrubs, I. asprella had higher SLA and chlorophyll contents, indicating that it adapted to shade environment to increase light capture and maintain high light use efficiency. This can help to increase carbon assimilation to cope with the shaded environment. However, the higher starch and nonstructural carbohydrates (NSCs) in the leaves of I. asprella also suggested that it had greater carbon assimilation and storage. Additionally, the similar performance of the three shrubs was also found in four mature plantations, suggesting that the nature of the understory plants also, to some extent, determined their growth and survival rate in the shade environment. Therefore, I. asprella can adapt well to the shaded environment of restored mature plantations. Thus, we recommend that I. asprella is a suitable and alternative species for understory regeneration in the reforested mature plantations of southern China. [ABSTRACT FROM AUTHOR]

Artificial light at night (ALAN) demonstrated a new ecological factor that influences organisms through a multi-approach. Yet, the impacts of ALAN on understory plants remain largely unknown. We evaluated whether ALAN would affect the leaf mass per area (LMA) of understory plants through a two-year field light experiment in a tropical rubber plantation in south China. We hypothesized that ALAN could impact the understory in two ways: by directly supplementing light to aboveground plant parts (which increases LMA) and indirectly affecting soil nutrient composition by attracting insects (which decreases LMA). We selected two species: Colocasia gigantea, representing shade-tolerant species, and Melastoma candidum, representing light-demanding species. We measured canopy openness, LMA, soil nutrients, and individual distance away from light resources. Our Bayesian linear mixed model showed a negative relationship between LMA and the strength of ALAN, indicating that ALAN may influence LMA more indirectly by enhancing soil nutrient availability rather than directly acting as a light resource. This relationship was significant for Colocasia gigantea but not for Melastoma candidum. These results suggest that ALAN might have complex and species-specific impacts on the understory ecosystem. Our study underscores the need for continued research and informed management of anthropogenic ecosystems. [ABSTRACT FROM AUTHOR]

Vascular plant species (VP) and bryophytes (B) constitute a significant portion of forest biodiversity and respond to both management intensity and natural disturbances within forests. In this study, we investigated the cross-taxa congruence between understorey VP and B at both diversity and composition levels across a wide range of sustainably managed forests in Slovenia. The taxonomic and functional characteristics of the selected plant groups were studied, with a particular emphasis on ground-dwelling species. We employed a trait-based approach to examine the functional characteristics. On average, the species richness of B in sustainably managed temperate forests increased with the corresponding number of VP. Furthermore, a moderate positive correlation in species composition between the studied groups of ground-dwelling organisms was also observed. The ground-dwelling VP and B were congruent in terms of trait-based composition, which was influenced by soil reaction and nutrients and light availability, while trait-based diversity was only slightly similar in response to moisture. A negative correlation between the composition of stress-tolerant VP and B hemeroby was found, indicating forest environments with a low level of disturbance. This is likely due to the sustainable management of Slovenian forests, where climate change and natural disturbances have intensified in recent years. A cross-taxon comparison of the two groups at four different levels, namely taxonomic-based diversity and composition and trait-based diversity and composition, revealed varying degrees of congruence. It is therefore important to monitor the status and temporal trends of both groups from different aspects to draw reliable conclusions. [ABSTRACT FROM AUTHOR]

IntroductionThe collapse of macroalgal habitats is altering the structure of benthic communities on rocky shores globally. Nonetheless, how the loss of canopy-forming macroalgae influences the structure of epilithic microbial communities is yet to be explored. MethodsHere, we used experimental field manipulations and 16S-rRNA-gene amplicon sequencing to determine the effects of macroalgal loss on the understory bacterial communities and their relationship with epiphytic bacteria on macroalgae. Beds of the fucoid Hormosira banksii were exposed to different levels of disturbance resulting in five treatments: (i) 100% removal of Hormosira individuals, (ii) 50% removal, (iii) no removal, (iv) a procedural control that mimicked the removal process, but no Hormosira was removed and (v) adjacent bare rock. Canopy cover, bacterial communities (epilithic and epiphytic) and benthic macroorganisms were monitored for 16 months.ResultsResults showed that reductions in canopy cover rapidly altered understory bacterial diversity and composition. Hormosira canopies in 50% and 100% removal plots showed signs of recovery over time, but understory epilithic bacterial communities remained distinct throughout the experiment in plots that experienced full Hormosira removal. Changes in bacterial communities were not related to changes in other benthic macroorganisms.DiscussionThese results demonstrate that understory epilithic bacterial communities respond rapidly to environmental disturbances at small scales and these changes can be long-lasting. A deeper knowledge of the ecological role of understory epilithic microbial communities is needed to better understand potential cascading effects of disturbances on the functioning of macroalgal-dominated systems.

Tropical drylands are among the most threatened ecosystems worldwide, and fewer than 10% of tropical dry forests in Hawai'i remain intact. Terrestrial arthropods comprise most of the endemic fauna on many islands, including Hawai'i, where they provide ecosystem services such as pollination, decomposition, and a reliable prey base for predators. The objective of our study was to measure understory arthropod diversity and relative abundances in two common habitat types within dryland Hawai'i—a non-native grassland, dominated by Cenchrus setaceus (fountain grass) with few native shrubs, and a native woodland, dominated by Metrosideros polymorpha ('ōhi'a). We used generalized additive models to examine patterns of understory arthropod dynamics measured monthly or bimonthly in relation to the two habitat types and local climatic variables. We found that temperature and habitat type were significant predictors of the abundance of certain arthropod families and orders. A greater abundance of spiders was in the woodland than grassland habitat, and more beetles and ants (particularly the Argentine ant, Linepithema humile) were in the grassland than woodland habitat. Temperature significantly predicted overall family-level richness and diversity of arthropods as well as Araneae, Heteroptera, Hymenoptera, and Lepidoptera abundance. Precipitation significantly predicted Heteroptera abundance. Significant positive associations were found among some arthropod groups, including several arachnid groups and families of Hemiptera. Documentation of insect and other arthropod community dynamics improves our understanding of ecological community function, supporting management of island communities comprised of both native and non-native species. [ABSTRACT FROM AUTHOR]

Selective browsing by deer on young trees may impede the management goal of increasing forest resilience against climate change and other disturbances. Deer population density is often considered the main driver of browsing impacts on young trees, however, a range of other variables such as food availability also affect this relationship. In this study, we use browsing survey data from 135 research plots to explore patterns of roe deer (Capreolus capreolus) browsing pressure on woody plants in mountainous forests in central Europe. We fitted species‐specific generalised linear mixed models for eight woody taxa, assessing the potential effects of understory characteristics, roe deer abundance and lying deadwood on browsing intensity. Our study reveals conspecific and associational effects for woody taxa that are intermediately browsed by roe deer. Selective browsing pressure was mediated by preferences of plants, in that, browsing of strongly preferred woody taxa as for example mountain ash (Sorbus aucuparia) and of least preferred woody taxa, for example Norway spruce (Picea abies) was not affected by the surrounding understory vegetation, while browsing pressure on intermediately browsed species like for example silver fir (Abies alba) was affected by understory characteristics. Contrary to our expectations, roe deer abundance was only positively associated with browsing pressure on silver fir and bilberry (Vaccinium myrtillus), while all other plants were unaffected by deer abundance. Finally, we did not find an influence of lying deadwood volume on the browsing pressure on any woody‐plant species. Overall, our results indicate that patterns in browsing preference and intensity are species‐specific processes and are partly affected by the surrounding understory vegetation. Current management strategies that aim to reduce browsing pressure through culling may be inefficient as they do not address other drivers of browsing pressure. However, managers also need to consider the characteristics of the local understory vegetation in addition to deer abundance and design species‐specific plans to reduce browsing on woody plant taxa. [ABSTRACT FROM AUTHOR]

We assessed the understory herb-layer species composition in response to tree vegetation and its associated environmental factors in the reforested area of the Kulon Progo Community Forestry, Yogyakarta, Indonesia. The understory herb-layer composition among different stand types, including Pinus (PN), Aleurites-Swietenia (AS), Swietenia-Acacia (SA), Melaleuca-Acacia (MA) and Tectona-Dalbergia (TD), was compared using some comparison analyses. The influence of tree vegetation characteristics and associated environmental factors on the understory herb-layer species was analyzed by employing canonical correspondence analysis (CCA). Our result showed variation in understory herb-layer species composition despite equality in richness and diversity indices. Among all stand types, the MA stand showed fewer shade-tolerant species, and the TD stand exhibited the smallest number of shade-intolerant species. Seedling availability also varied between AS and MA, which contained fewer seedling species. One of the main species in the two stands did not even regenerate. Moreover, all indicator species in MA were shade-intolerant species with invasive characteristics, while those in TD were shade-tolerant and semi-shade-tolerant species. CCA showed that stand types held an important role in the herb-layer species composition, where the number of shade-tolerant and seedling species commonly native to forest were directly proportional to tree canopy coverage, silt proportion in soil texture and concentration of soil organic carbon yet inversely proportional to below-stand utilization. In contrast, the number of shade-intolerant species had positive correlation to below-stand utilization and inversely to other correlated factors. Our study also indicated the possibility of tree vegetation controlling several environmental factors, where the increase in canopy coverage was followed by an increasing proportion of silt in soil texture and concentration of soil organic carbon, as well as a decreasing percentage of below-stand utilization. Accordingly, we recommend tree species enrichment with dense-canopy trees and adaptive management of below-stand utilization for better forest development and tree regeneration. This finding provides important knowledge for evaluation and improvement in the ecological restoration of degraded forests. [ABSTRACT FROM AUTHOR]

The effect of stand density on the soil bacterial community and diversity remains unclear. Spectrophotometry and full-length 16S rRNA sequences were used to determine the effects of planting density on soil physicochemical attributes and the diversity of soil bacterial and understory vegetation in a young Phoebe zhennan plantation at five densities. The findings showed that stand density had significant effects on the total nitrogen, ammonium nitrogen ( NH 4 + - N ), nitrate-nitrogen ( NO 3 − - N ), organic carbon, and the dominance and evenness of shrubs. Candidatus Udaeobacter and Candidatus Soilbacter were the two most common genera across the five stand densities. The density D5 (850 stems/hm2) demarcated from the others with a lower diversity of soil bacteria. Overall, the relatively low- and middle-density plantations were more conducive to complex and stable understory vegetation, bacterial communities, and soil nutrient cycles. The functional categories of the bacterial communities revealed a high proportion associated with chemoheterotrophy, aerobic chemoheterotrophy, and nitrogen fixation. Bacterial diversity and function were significantly influenced by soil pH, NH 4 + - N , NO 3 − - N , total phosphorus, and available phosphorus. However, there were no significant correlations between soil physicochemical attributes, understory vegetation, and bacterial diversity. Therefore, we speculated that the key drivers of the soil bacterial community were the soil physicochemical attributes and that stand density affected the soil bacterial community diversity by changing the soil physicochemical attributes. Overall, P. zhennan plantations with densities below 600 stems/hm2 were conducive to complex and stable soil bacterial communities and nutrient cycles. [ABSTRACT FROM AUTHOR]

The soil in the upstream Bengawan Solo watershed is at high risk of degradation related to a high erosion rate. Finding the proper crop type with land suitability is critical to protect against further soil degradation. This study aimed to determine the land suitability of white turmeric (Curcuma zedoaria) and the limiting factors in the upstream Bengawan Solo watershed community forest. This research was descriptive-explorative based on a survey of four land map units (LMUs) of Sumberejo village (LMU1, LMU2, LMU3, and LMU4), Batuwarno, Wonogiri. The number of sample points at each LMU depended on the total area of the LMU and was repeated four times. LMU results from overlay soil type maps, administrative maps, rainfall maps, and slope maps. Land suitability assessment was analyzed using the matching method. The land suitability classes of the upstream Bengawan Solo for white turmeric were S3 eh, and N eh. The limiting factors on land suitability for white turmeric are erosion hazards and slopes. The efforts to improve the limiting factor can be made by contour cultivation and repairing the terrace.

Introduction: The spread of antimicrobial resistance in natural environments continues to be reported throughout the world; nevertheless, there is no study about phytotelms (water in the natural cavities of plants) in the deep understory of tropical cloud forests from Costa Rica. Objective: To detect phytotelm antibiotic-resistant bacterial strains in a Costa Rican forest and nearby town. Methods: We used the disk diffusion method to analyze the antimicrobial resistance of 10 gram-negative bacterial strains from phytotelm water collected from 10 bromeliads and 10 heliconias in both sites. Results: Three strains were multidrug resistant to more than three antibiotics in each site, and only one strain was susceptible to all antibiotics. Antibiotic resistance was similar in both environments. Conclusions: Phytotelm can be a rapid, cost-effective, and simple source for detecting antimicrobial resistance in unexplored environments.

Solar-induced chlorophyll fluorescence (SIF) has been widely used as a prospective proxy of plant photosynthesis to accurately detect the response of vegetation to climate change and study terrestrial ecosystem carbon cycle. However, the challenge of estimating vegetation gross primary product (GPP) based on SIF observations remains unresolved due to the confounding effects of leaf physiology and canopy structure, especially the vertical heterogeneity of plant attributes. Radiative transfer models are ideally suited to investigate the variability in radiance signals including fluorescence, but previous studies lack vertically layered spectra to validate the model. In this study, we developed a vertically layered hyperspectral system and proposed an innovative framework for assessing vertical characteristics of SIF and improving the estimation of GPP based on SIF in a subtropical evergreen forest. The global sensitivity analysis on Soil-Canopy-Observation of Photosynthesis and Energy fluxes (SCOPE) model with vertical profiles showed that chlorophyll content (Cab), leaf inclination distribution (LIDFa), leaf area index (LAI), and senescent material (Cs) dominate the vertical variations in reflectance (Ref) and SIF. We found that the vertical characteristics of SIF were mainly impacted by these parameters of the adjacent vertical layer, except for the effects of LAI across the vertical layers on the observed understory SIF U , which were approximately equivalent. 7.8 ± 1.7% of the SIF U was transferred to the top of canopy, contributing up to 17% of the SIF observed on the top of canopy (SIF TOC) during the year. Furthermore, our findings suggest that substituting the observed SIF TOC with the total emitted SIF, particularly from the simulated overstory and understory SIF, could enhance the correlation between GPP and SIF with an increased R2 (ΔR2 = 0.09). This study highlights the importance of accounting for the contribution of the layered SIF in the quantification of the total SIF emission and can benefit the GPP estimation based on SIF signals in subtropical evergreen forests with high canopy density. [ABSTRACT FROM AUTHOR]

Seed bank compositions provide a record of past disturbances, the legacies of which may last thousands of years. Our goal was to determine if sites defined historically by fire-related (pyrophilic) tree species have seed bank compositions different from sites defined historically by pyrophobic tree species. We selected three 80+ year-old forested sites within the Monongahela National Forest, West Virginia, to represent three pyrophilic zones based on percent-pyrophilic-witness tree cover: Low (0–10%), Medium (40–50%), and High (80–90%). Soil plugs were collected to evaluate the seed bank and determine soil nutrients and charcoal abundance; cover of all understory plants was also estimated. The results, supported by the charcoal analyses, show significant differences between extant and seed bank vegetation, pyrophilic zones, and pyrophilic zones within each vegetation lifeform (extant vs. seed bank). The High zone seed bank had the greatest species richness, the most pyrophilic species, and differed the most from its extant vegetation, but was the least dense of all zones and a pyrophobic species ranked among its top five indicator species. These findings indicate mesophication and a depletion of pyrophilic species in the seed bank. The High site appears to be reaching a potential threshold where passive recovery to fire-adapted conditions may be unlikely. [ABSTRACT FROM AUTHOR]

Remote sensing technology is a timely and cost-efficient method for leaf area index (LAI) estimation, especially for less accessible areas such as mangrove forests. Confounded by the poor penetrability of optical images, most previous studies focused on estimating the LAI of the main canopy, ignoring the understory. This study investigated the capability of multispectral Sentinel-2 (S2) imagery, airborne hyperspectral imagery (HSI), and airborne LiDAR data for overstory (OLe) and understory (ULe) LAI estimation of a multi-layered mangrove stand in Mai Po, Hong Kong, China. LiDAR data were employed to stratify the overstory and understory. Vegetation indices (VIs) and LiDAR metrics were generated as predictors to build regression models against the OLe and ULe with multiple parametric and non-parametric methods. The OLe model fitting results were typically better than ULe because of the dominant contribution of the overstory to the remotely sensed signal. A single red-edge VI derived from HSI data delivered the lowest RMSE of 0.12 and the highest R2adj of 0.79 for OLe model fitting. The synergetic use of LiDAR metrics and S2 VIs performed best for ULe model fitting with RMSE = 0.33, R2adj = 0.84. OLe estimation benefited from the high spatial and spectral resolution HSI that was found less confounded by the understory. In addition to their penetration attributes, LiDAR data could separately describe the upper and lower canopy, which reduced the noise from other components, thereby improving the ULe estimation. [ABSTRACT FROM AUTHOR]

Abstract Introduction Cameroon’s tropical rainforests are nowadays strewn with rural forests maintained by local populations; however, these forests are not officially recognized in the non-permanent forest domain. Rural forests are non-delimited riparian areas within the dense moist forest, reserved for rural housing, agricultural activities and agroforestry practices, freely exploited by the local communities for their livelihood without them having any rights to artisanal and commercial logging. This study aimed at contributing to the flora knowledge and the conservation state of woody plant species in rainforests. The study was carried out in two rural forests located in the Eastern and Southern agroforestry zones of Cameroon. Methods The method adopted for floristic inventories combined a fixed area sampling unit and a variable area sampling unit. Woody individuals with diameter at breast height (dbh)

With progressing climate change, increasing weather extremes will endanger tree regeneration. Canopy openings provide light for tree establishment, but also reduce the microclimatic buffering effect of forests. Thus, disturbances can have both positive and negative impacts on tree regeneration. In 2015, three years before an extreme drought episode hit Central Europe, we established a manipulation experiment with a factorial block design in European beech (Fagus sylvatica L.)-dominated forests. At five sites located in southeastern Germany, we conducted three censuses of tree regeneration after implementing two different canopy disturbances (aggregated and distributed canopy openings), and four deadwood treatments (retaining downed, standing, downed + standing deadwood and removing all deadwood), as well as in one untreated control plot. In addition, we measured understory light levels and recorded local air temperature and humidity over five years. We (i) tested the effects of experimental disturbance and deadwood treatments on regeneration and (ii) identified the drivers of regeneration density as well as seedling species and structural diversity. Regeneration density increased over time. Aggregated canopy openings supported species and structural diversity, but reduced regeneration density. Tree regeneration was positively associated with understory light levels, while maximum vapor pressure deficit influenced tree regeneration negatively. Deadwood and browsing impacts on regeneration varied and were inconclusive. Our study indicates that despite the drought episode regeneration in beech-dominated forests persisted under moderately disturbed canopies. However, the positive effect of increased light availability on tree regeneration might have been offset by harsher microclimate after canopies have been disturbed. [ABSTRACT FROM AUTHOR]

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The soil in the upstream Bengawan Solo watershed is at high risk of degradation related to a high erosion rate. Finding the proper crop type with land suitability is critical to protect against further soil degradation. This study aimed to determine the land suitability of white turmeric (Curcuma zedoaria) and the limiting factors in the upstream Bengawan Solo watershed community forest. This research was descriptiveexplorative based on a survey of four land map units (LMUs) of Sumberejo village (LMU1, LMU2, LMU3, and LMU4), Batuwarno, Wonogiri. The number of sample points at each LMU depended on the total area of the LMU and was repeated four times. LMU results from overlay soil type maps, administrative maps, rainfall maps, and slope maps. Land suitability assessment was analyzed using the matching method. The land suitability classes of the upstream Bengawan Solo for white turmeric were S3 eh, and N eh. The limiting factors on land suitability for white turmeric are erosion hazards and slopes. The efforts to improve the limiting factor can be made by contour cultivation and repairing the terrace. [ABSTRACT FROM AUTHOR]

Functional traits impact species interactions, community composition, and ecosystem functioning. However, few studies have focused on the diversification and phylogenetic correlation of multiple functional traits over geological time. We conducted phylogenetic comparative analysis for boreal forest understory species in northeast China to examine the diversification and phylogenetic correlation in several functional traits: leaf area (LA), leaf carbon content (LCC), leaf dry matter content (LDMC), leaf nitrogen content (LNC), plant height (PH), and specific leaf area (SLA). Phylogenetic signals showed that there were very low levels of phylogenetic niche conservatism (PNC) in understory leaf‐related traits and plant height, suggesting divergence of functional traits for the co‐occurring understory species. The disparity through time analyses (DTT) indicated that trait disparities mainly originated during recent divergence events and there were no differences in the observed trait disparities compared with that expected under Brownian motion. Furthermore, we found both positive and negative phylogenetic correlations among the measured functional traits. The very low levels of PNC suggest that these functional traits diverged among co‐occurring understory species, and that those species are distantly phylogenetically related. The phylogenetic correlations among traits may be caused by both positively and negatively correlated adaptions that correspond to resource acquisition strategies. This study provides evidence that divergence in functional traits may reflect understory adaptions to boreal conditions. [ABSTRACT FROM AUTHOR]

The lower Mississippi River Valley and connecting tributaries have lost an estimated 80% of original bottomland hardwood forested wetlands to agricultural conversion. For the past three decades, the Wetlands Reserve Program has restored thousands of wetlands with the objective of recovering wetland functions and supporting wildlife diversity. To inform future restoration decisions, we assessed the recovery of the naturally colonizing understory plant community in wetlands restored from row‐crop agriculture in western Kentucky, U.S.A. We measured six floristic variables in 16 wetlands along a gradient of disturbance (degraded, restored, and reference) and a chronosequence ranging from 0 to 13 years since restoration. We found that reference wetlands had significantly higher floristic quality and a higher proportion of woody and perennial species than restored wetlands. Over time, the proportion of non‐native species decreased in restored wetlands and floristic quality increased. The successional trajectory of naturally colonizing plant communities in restored wetlands was likely inhibited by dispersal limitations, thus future projects should focus on optimizing project locations to increase recruitment, continue afforestation efforts for heavy seeded trees, and consider planting native understory species. Long‐term project monitoring, approximately three decades, will likely provide deeper insight into recovery trajectory. With ongoing biodiversity loss and the effects of climate change, the success of wetland restorations has important local and global implications. [ABSTRACT FROM AUTHOR]

Objective: To characterize the understory species associated with a pine-oak forest in the Sierra Mariscal region, Chiapas. Design/methodology/approach: Six 40 m² subplots were established to evaluate the cover, abundance and identity of shrub, herbaceous and sapling components of the understory. Floristic diversity was determined. The level of disturbance was evaluated using the observation method. An analysis of variance and comparison of means by Tukey (p<0.05) between structural variables was applied. The relationship between disturbance levels and study sites was performed by correspondence analysis. Results: The understory is composed of five tree species, three herbaceous and two shrub species. The largest diameter (p≤0.0001 and F=27.6) corresponds to herbaceous Cortaderia selloana (5.38±0.94 cm) and Pteridium aquilinum (4.5±0.96 cm). The greatest height corresponds to Quercus sp. saplings (126.3±75.9 cm) and the herbaceous Cenchrus sp. (110.2±54.1 cm) and Pteridium aquilinum (91.7±40.9 cm), the latter having the highest density (4050 ind. ha-1 ) and cover (16.2%). Floristic diversity was low in all six sites. Site six was the most diverse and site three the most disturbed. Study limitations/implications: The study comprised a limited and insufficient area to generalize the conditions of pine-oak forests in the Chiapas highlands. It is suggested to expand the study universe and increase the number of replications. Findings/conclusions: Variability in understory structure and composition was found that corroborates the relationship between forest diversity and disturbance. [ABSTRACT FROM AUTHOR]

• Process-based models to simulate understorey community dynamics are still lacking. • This paper proposes a new model specifically designed for understorey communities. • Validation using experimental data shows that our model concept is promising. • To further advance the model, new data on functional traits and processes are needed. Understorey communities in temperate forests have often been ignored in the study of the dynamics of forest structure and function, while evidence for the importance of this biotic layer is accumulating. Scarcity in understorey data with a high temporal resolution, and understorey data types that do not match popular vegetation modelling concepts, have limited previous modelling attempts to empirical models that are hard to extrapolate to new environmental conditions. Here we introduce a new process-based modelling approach designed specifically for understorey communities, whose dynamics are generally characterised by changes in (species-specific) cover data, while species characterisation is largely based on plant functional trait measurements. By confronting the model to data gathered in a large understorey mesocosm experiment, we show that our model concept is promising, and is able to predict performance differences within a species. Predictions across species were found to be more challenging, and will likely require new data on understorey traits and processes. In particular, new data on understorey carbon assimilation rates, vegetative phenology, plant architecture and belowground processes, are needed to advance the field of process-based understorey modelling. [ABSTRACT FROM AUTHOR]

Insect communities in tropical forests tend to be structured vertically and with respect to tree fall gaps and edges. Furthermore, insect communities vary over time. Insight into such habitat specificity and temporal variation is needed to design and interpret biodiversity surveys and to compare conservation value among habitats. Some aspects of tropical insect community structure, such as the proportion of canopy specialists and temporal variation, vary among biogeographical regions and climatic zones. To date, few regions have been sampled systematically, so generalization remains difficult. We compared fruit-feeding butterfly communities among understory, canopy, natural treefalls, and forest edge, in a tropical forest of the Western Ghats, a strip of rainforest that is isolated from Sundaland, the large rainforest block of South-East Asia. During a yearlong study, we captured 3018 individuals belonging to 32 species and representing 14 genera. While some butterflies were captured in the canopy, no species was significantly more abundant in the canopy than in the understory. This observation was contrary to studies elsewhere in the tropics where 14–55% of the species could be classified as canopy specialists. Even though the largest number of species was captured at forest edges, species diversity was highest in the gaps. The communities at the forest edge differed importantly from those in treefall gaps: at the forest edge, we caught grassland species in addition to the forest species. Larger treefall gaps had higher butterfly abundance than smaller gaps. Both abundance and diversity peaked during the late monsoon season, and all common species in our sample also peaked during this period. The spatiotemporal community structure appears to depend on biogeography (less vertical stratification further from large forest blocks) and climate (more synchrony among species in seasonal abundance when there is a more severe dry season). [ABSTRACT FROM AUTHOR]