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In this study, we investigated the importance of plant cover for secondary succession and soil fungal community development in remediated substrates after EDTA washing of metal-contaminated soils. The abundance of the total fungal community, determined by ITS fungal marker genes (Internal Transcribed Spacer region), and root colonisation by arbuscular mycorrhizal (AM) fungi were monitored in two types of soil material (calcareous and acidic) sown with perennial ryegrass (Lolium perenne L.) and without plant cover (bulk soil). Four months after the start of the experiment, the abundance of ITS genes in the soil clearly showed that the presence of plants was the main factor affecting the total fungal community, which increased in the rhizosphere soil in most treatments, while it remained at a low level in the bulk soil (without plants). Interestingly, the addition of environmental inoculum, i.e., rhizosphere soil from a semi-natural meadow, did not have a positive effect on the abundance of the total fungal community. While fungal ITS genes were detected in soils at the end of the first growing season, arbuscular mycorrhizal (AM) structures were scarce in Lolium roots in all treatments throughout the first season. However, in the second season, more than a year after the start of the experiment, AM fungal colonisation was detected in Lolium roots in virtually all treatments, with the frequency of colonised root length ranging from 30% to >75% in some treatments, the latter also in remediated soil. This study demonstrates the importance of plants and rhizosphere in the development and secondary succession of fungal communities in soil, which has important implications for the revitalisation of remediated soils and regenerative agriculture.

Ecological succession after disturbance plays a vital role in influencing ecosystem structure and functioning. However, how global change factors regulate ecosystem carbon (C) cycling in successional plant communities remains largely elusive. As part of an 8-year (2012-2019) manipulative experiment, this study was designed to examine the responses of soil respiration and its heterotrophic component to simulated increases in precipitation and atmospheric nitrogen (N) deposition in an old-field grassland undergoing secondary succession. Over the 8-year experimental period, increased precipitation stimulated soil respiration by 11.6%, but did not affect soil heterotrophic respiration. Nitrogen addition increased both soil respiration (5.1%) and heterotrophic respiration (6.2%). Soil respiration and heterotrophic respiration linearly increased with time in the control plots, resulting from changes in soil moisture and shifts of plant community composition from grass--forb codominance to grass dominance in this old-field grassland. Compared to the control, increased precipitation significantly strengthened the temporal increase in soil respiration through stimulating belowground net primary productivity. By contrast, N addition accelerated temporal increases in both soil respiration and its heterotrophic component by driving plant community shifts and thus stimulating soil organic C. Our findings indicate that increases in water and N availabilities may accelerate soil C release during old-field grassland succession and reduce their potential positive impacts on soil C accumulation under future climate change scenarios. [ABSTRACT FROM AUTHOR]

In the lowlands and uplands of Central Europe, which were inhabited continuously from the very start of the Holocene to the present times, it is difficult to find territories suitable for investigation of natural baselines. For this reason, we picked the complicated rocky terrain of one upland area in NE Bohemia called Adrspach because, based on the absence of archeological finds, it was supposed to have never been deforested or managed by people. The remote and inhospitable character of this particular area further encouraged this assumption. To our great surprise, however, high-resolution pollen analyses, supplemented by analyses of non-pollen palynomorphs and microscopic charcoals reveals that the local forest ecosystem had a dynamic development over entire Holocene. We were able to correlate this high-resolution understanding of vegetation successions with repeated fire disturbances. Was this fire disturbance dynamic natural? Subsequent archeological exploration and excavation in the area brought unexpected evidence, pointing to rather continuous human presence throughout most of the Holocene. From the Early Mesolithic to the Late Neolithic, available evidence suggests a hunter-gatherer mode of resource management. From the start of the Late-Holocene (ca 4 ka BP), the occurrence of coprophilous fungal spores and secondary anthropogenic pollen indicators suggest this area was impacted by recurrent domestic animal grazing. Testing this approach also in other remote forested areas of Central Europe, we argue, can have far-reaching implications for understanding long term human-environment agency by transforming our understanding of alternative subsistence and land use strategies during prehistory. At the same time, this can significantly alter existing concepts used in Central European nature conservation strategies, which tend to be based on an underlying assumption that our work challenges – the survival of little impacted wilderness at the Holocene scale. [ABSTRACT FROM AUTHOR]

Aims: We explored the trends in soil fungal and bacterial patterns and their responses to plant and soil characteristics with increasing site age in abandoned farmland in karst areas. Methods: Illumina sequencing of 16S rRNA and ITS genes was used to characterize the soil bacterial and fungal diversities in farmland, farmland abandoned for 3, 6, 20, and 40 years, and old-growth forests in Southwest China. Plant diversity, community-weighted mean (CWM) leaf and branch traits, soil physical and chemical properties and metal element concentrations were also investigated. Results: Bacterial diversity decreased slightly with increasing site age, while fungal diversity first increased and then decreased. Ascomycota was the dominant fungal phylum, and its abundance decreased significantly, from 83.21% in farmland to 49.66% in old-growth forests, while that of Basidiomycota increased significantly from 4.52 to 35.43%. The soil bacterial community was dominated by Proteobacteria, Actinobacteria, Acidobacteria, and Chloroflexi. The fungal and bacterial diversities were mainly affected by soil properties. At the older sites, high levels of soil nitrate nitrogen (N), ammonium-N, total N, soil organic carbon, calcium, and magnesium and relatively low levels of soil potassium and available phosphorus (P) resulted in decreased bacterial diversity. Fungal diversity was positively affected by soil total P and pH and negatively affected by soil iron and copper. The bacterial and fungal compositions were jointly affected by soil properties and CWM leaf and branch traits. Conclusions: Our findings indicate that soil bacterial and fungal diversities and compositions changed significantly during secondary succession in karst areas. Microbial diversity was determined by soil properties, and compositions were jointly driven by plant and soil properties. [ABSTRACT FROM AUTHOR]

The characteristics of plant and soil bacterial communities in forest ecosystems have been reported, but our understanding of the relationship between plant communities and soil bacteria in different stages of secondary tropical rainforest succession is still poor. In June 2018, three different natural successional stages of tropical lowland rainforests, early (33 years), early-mid (60 years), and mid successional stage (73 years), in Hainan Island, China, were selected for this study. By conducting field investigation and 16S rRNA gene high-throughput sequencing, the composition and diversity of tree communities, the niche overlap of tree species with legumes among tree species, and the diversity and composition of soil bacterial communities and co-occurrence networks within communities across the successional stages were investigated. The results showed that plant richness and species diversity increased significantly during the secondary succession of tropical lowland rainforests. The order of positive correlations between nitrogen-fixing legumes and other species in plant communities was early-mid > mid > early successional stage. Soil nutrient content and soil bacterial richness were highest in the early-mid stages of succession, followed by mid and early stages of succession. Organic matter (OM), total nitrogen (TN), alkali nitrogen (AN), and available phosphorus (AP) had a stronger positive impact on soil bacterial communities. Co-occurrence network analysis showed that with the advancement of rainforests succession, the negative correlation between soil bacterial species decreased, and the community stability increased. Overall, as a result of tropical lowland rainforest secondary natural succession, the richness and diversity of plant communities increased, which altered the living conditions of nitrogen-fixing legumes and the soil properties, and the network complexity of soil bacterial communities increased with the rising of rainforest soil nutrient content. [ABSTRACT FROM AUTHOR]

Aims: Light availability varies drastically in forests, both vertically and horizontally. Vertical light heterogeneity (i.e., patterns of light attenuation from the forest canopy to the floor) may be related to light competition among trees, while horizontal light heterogeneity (i.e., variations in light intensity at a given height within forests) may be associated with light‐niche partitioning among tree species. However, light heterogeneity in vertical and horizontal directions and their associations with forest structure are rarely studied to date. Here we report the first comprehensive study to compare the vertical and horizontal light heterogeneity in differently aged forests in two forest types. Location: Twelve forest stands of different ages in cool‐temperate forests (consisting of deciduous broad‐leaved trees) and five of different ages in warm‐temperate forests (evergreen conifer and deciduous broad‐leaved trees) in Japan. Methods: We measured vertical light profiles at 1‐m intervals from the understorey (1 m above the ground) to the top canopy (12–22 m depending on stands) at 16 locations for each stand (20 m × 20 m). We also measured structural parameters (diameter at breast height, height, and crown dimensions) for all major trees in these stands. Results: Along the secondary successional gradients, the vertical and horizontal light heterogeneity changed in a systematic manner in both forests. The vertical light attenuation rate was steeper in early succession and more gradual in late succession, and the horizontal light heterogeneity was relatively small in early succession and more pronounced in late succession. The vertical light attenuation rate was different between the two forest types; the light intensity dropped more sharply from the canopy surface in the cool‐temperate forests due to the crown being vertically shorter and denser (i.e., higher leaf density per unit volume). Conclusion: In early succession, a steeper light attenuation rate is likely related to the strong light competition among co‐occurring trees and thus a self‐thinning process. In late succession, the high spatial light heterogeneity in forests (i.e., larger horizontal light heterogeneity and gradual light attenuation rate) may allow more species to partition light, and thus may enhance species coexistence and diversity. [ABSTRACT FROM AUTHOR]

Feedbacks within ecosystems can lead to internal reinforcement of the current state providing ecosystem resilience. Often, multiple biotic interactions across trophic levels play a role in such feedbacks, yet these are generally studied independently, obscuring the relative importance of interactions among different factors. We look at various potential feedbacks in intact and degraded mesic forests on Hawaiʻi Island where managers have planted native Acacia koa (koa) trees in an attempt to jumpstart succession in former cattle pastures. These restoration forests, however, have not undergone secondary succession, instead maintaining a koa overstory with an exotic pasture grass understory. We contrasted different trophic level processes that influence the capacity for natural understory regeneration: feedbacks between bird‐mediated seed rain and fruiting understory ("top‐down"), as well as links between understory composition and microhabitats for native seed germination ("bottom‐up"). We quantified bird‐mediated seed rain under canopy trees along transects spanning intact, fragmented, and restoration forests. Along these transects, we established plots around focal overstory trees to measure abundance of fruiting understory species, ground cover (e.g., exotic grass, bryophyte), and obtained estimates of bird density to evaluate the contribution of each of these factors to seedling abundance. We also used a factorial seed addition/grass removal experiment to directly compare the influence of seed rain and germination substrate. We found evidence of both top‐down and bottom‐up feedbacks that reinforced the current state of each forest type. In the intact and fragmented forests, the combination of comparatively high seed rain and ample germination substrate is likely critical for maintaining a diverse forest system. In contrast, exotic grasses exhibit priority effects in restoration forests, inhibiting seed germination and effectively negating any benefits that could be derived from bird‐mediated seed rain. Such internal reinforcement suggests that active, rather than passive, restoration would be beneficial to increase forest diversity in restoration areas. [ABSTRACT FROM AUTHOR]

We evaluated the effects of riparian forests restoration on anuran communities in the Brazilian Cerrado. We analyzed five riparian reforested fragments around a reservoir of an hydroelectric plant using microhabitat variables (humidity, canopy opening, amount of leaf litter and vegetation density), the dominant landscape (matrix type, fragment width) and reforestation age. We tested whether anuran abundance, richness and diversity were influenced by these variables using generalized linear models. Matrix type and fragment width were limiting factors for anurans to reach and establish themselves in riparian forest fragments, whereas microhabitat and reforestation age did not influence anuran succession. We conclude that reforestation in the midst of impermeable matrices creates anuran communities dominated by widely-distributed species that live in open areas, reflecting the highly modified surrounding habitat. [ABSTRACT FROM AUTHOR]

Clearcutting exotic plantations favours natural regeneration processes in which seed banks may play an important role. In Andean high montane areas, after Pinus patula clearcutting, changes in soil pH and litter lead to increased fauna and flora biodiversity. However, the impact of these changes on seed banks remains unknown. The aims of the present study were to understand how seed bank richness, abundance, and composition changes after P. patula clearcutting, and to identify the role of aboveground cover, pH and litter cover on these seed bank variations. The study was conducted in three areas with different post-clearcutting ages (0, 2.5, 4.5 years), a P. patula plantation and in a high Andean forest patch. All these sites were located between 3 033 and 3 100 m.a.s.l. Seed bank abundance, richness and the number of seeds of the ten most abundant species increased in areas with 2.5 and 4.5 years after clearcutting. Moreover, seed bank composition was different among study areas. These changes were related to increasing aboveground vegetation cover and soil pH, and to decreasing litter cover. Seed banks contributed almost exclusively to the recovery of some herbaceous species; we recorded only one tree species recruit from the seed banks (Baccharis latifolia) in the forest soils; therefore, the natural regeneration processes may be constrained. Our results highlight the need to implement active restoration to accelerate high montane forest recovery in areas previously covered with pine tree plantations.

Successions in old fields were studied on the example of the Starobilski steppes within Luhansk Oblast (Ukraine), region located in the basin of the left tributaries of the Siversky Donets, in the southern spurs of the Central Russian Upland. Stationary surveys were conducted in the Striltsivsky Steppe affiliate of the Luhansk Nature Reserve, with 269 ha of old fields (26% of the area) in its territory. Geobotanical releves were performed in 26 plots of abandoned fields, constant monitoring surveys were carried out in 15–27 year-old abandoned fields in the territory of the Reserve and 5–15 year-old abandoned fields in the territory of its buffer zone. In total, the itinerary and detailed surveys were conducted for about 50 plots of abandoned fields. The restoration of the steppe communities was seen only in the plots where grazing and/or mowing took place, which prevented the formation of dense litter and distribution of woody species. The long domination of rhizome grasses (Elytrigia repens) were characteristic in conditions of moderate-level disturbance (in the reserve), transition to the domination of bunchgrasses (Festuca valesiaca) was seen at the age of around 25 years, during the transitional period (20–25 years) communities with unstable structure formed, comprising E. repens, F. valesiaca and forbs (Achillea pannonica and Fragaria viridis). Duration of the stage of segetal and ruderal species in the sites under low effect was 10 years, the communities of unstable structure formed at the age of 5–10 years. In the conditions of stable moderate and high effect of grazing (high disturbance), we observed formation of bunchgrass communities at the age of 15 years. In the unused plots, we saw formation of phytocoenoses of shrubs at different stages of succession, starting from 10 years. The most abundant group of such kind comprised thickets of Ulmus pumila (with E. repens and Poa angustifolia in the herbaceous layer) and Prunus stepposa. The peculiarity of contemporary processes in the abandoned fields related to exacerbation of the vegetation’s anthropogenic transformation is distribution of alien tree species from plantations, the most aggressive of which are Ulmus pumila, Fraxinus lanceolata, Acer negundo, Elaeagnus angustifolia. The peculiarity of the succession processes in the region of studies was the domination of species of broad ecological spectrum, characteristic for abandoned fields of northern forest-steppe regions (Bromopsis inermis, Calamagrostis epigeios, Poa angustifolia, Fragaria viridis) and southern steppe regions (Bromus sguarrosus, Anisantha tectorum, Achillea pannonica, Artemisia austriaca), certain communities form dependent on the climatic conditions and type of land use in the period of succession in particular plots.

ABSTRACT The ruderal babassu palm (Attalea speciosa) is expanding on large areas of degraded Amazon landscapes. Decomposition of leaves and roots is in the center of plant:soil interactions. We evaluated decomposition and nutrient concentrations of leaves and fine roots of babassu in comparison with two exotic reference species, Acacia mangium (slow degradability) and Leucaena leucocephala (fast degradability), in a 138-day litterbag assay carried out in secondary forest stands of different age and babassu abundance. We chose 4-mm over 2-mm mesh litterbags based on a pilot study. Babassu leaves degraded slower than leaves of A. mangium and L. leucocephala, and also had lower nitrogen, phosphorus and calcium concentrations in all stages of decomposition. By contrast, potassium concentrations in babassu leaves were higher than in both reference species at 0 and 50 days. Roots of all three species decomposed slower than leaves. Compared to the leaves, both biomass loss and nutrient concentrations differed less between babassu and reference-species roots, except for lower nitrogen concentration in babassu roots. Leaf-litter decomposition of all three species was significantly faster in old than in young secondary forest, suggesting an acceleration of decomposition along succession. Babassu leaves decomposed faster in old babassu-dominated than non-dominated secondary forest, pointing to the existence of specialized decomposer communities in babassu-dominated stands.

In order to review and complete our knowledge of the typology and synecology of the aspen communities from the central-southern Apennines, ten original relevés were performed on the Gargano plateau and a set of 35 relevés assigned to four community types (HP: Holco mollis-Populetum tremulae; MP: Melico uniflorae-Populetum tremulae; FP: Fraxino orni-Populetum tremulae; GP: Geranio versicoloris-Populetum tremulae) were assembled from literature. These relevés along with several environmental variables either measured or estimated were involved in cluster and ordination analyses. The relevés from Gargano formed a distinctive cluster and were assigned to a new community type (SP: Stellario holosteae-Populetum tremulae ass. nova), which can be considered an Adriatic synvicariant of HP that is distributed in similar habitats (doline bottoms) but on the Tyrrhenian escarpment. At low levels of floristic similarity, the grouping of relevés in two clusters induces a sharp separation between the aspen communities distributed in the central Apennines (MP and FP) and those from the southern Apennines (SP, HP and GP), which is mainly due to compositional differences in the regional species pool. The ordination scores of relevés were best related to terrain slope, soil nitrogen, elevation, air temperature, light availability and, to a lesser extent, to soil moisture and reaction. Unlike MP and GP that appear the most mesophilous, the FP stands display a slightly more xerophilous and acidophilous character induced by the steeper slopes on which they occur. The HP habitat is the driest and lightest very likely because of the open overlying canopy, in contrast to MP stands featuring a high shrub cover. The highest occurrence of nitrophilous species was observed in SP and MP. The management of these pioneer woods should be aimed at conservation, as they play an important role in the recovery of forest herb diversity along the ecological succession towards hardwood forests.

Fire affects vegetation and changes plant succession. In this paper, the vegetation of Sirachal Research Station, which burned in the summer of 2014, was studied and compared with the unburnt areas, based on biodiversity indices. The research was implemented as a factorial experiment in a completely randomized design. First, on the basis of physiognomy, the area was divided into three parts: shrubland, shrubland-rangeland, and rangeland. Each part was, then, divided into two sections, including a burnt area and an adjacent unburnt area (control area). In each area (burnt and unburnt), three sampling units were randomly assigned using PNP method, and vegetation measurements were subsequently performed. Based on data analysis, a total of 141 taxa were identified, belonging to 28 families and 95 genera, including one species of Gymnosperm, 19 monocotyledons and 121 dicotyledons in two burnt and unburnt areas of Sirachal Station. Based on the statistical analysis, using Past3 and SPSS softwares, there was no significant difference in the number of taxa between the vegetation of the burnt and unburnt areas. Of the indicators analyzed in Past3, the number of individual, the index of Menhinick's richness and the Shannon diversity index were significantly different in the treatments sampled from the burnt and unburnt areas. According to the Duncan test average, the number of individuals in the unburnt area, with a canopy cover below 25%, was greater than that in the burnt area, with the same canopy cover, however, no significant difference was observed between the individuals in the burnt area and unburnt area, with the same canopy cover of more than 25%. Also, the richness of the burnt area with a canopy of less than 5% is significantly higher than that in the unburnt area with the same canopy cover.

Three upheavals shaped southern Mexico to Panama (SMP) biodiversity: 1. The Great American Interchange that allowed migrations between the Neotropical and the Nearctic biogeographic realms; 2. human colonization with the generation of Mesoamerican cultures; and 3. the Spaniards’ arrival and globalization.Tectonic events generated a narrow piece of land with steep topography and high environmental heterogeneity, demanding high levels of local adaptation. Habitat size is usually restricted and reduced by frequent disturbances. Topography imposes few options for individuals forced to displace. Thus, extinction risks should be unusually high. Humans initiated an ongoing defaunation process and introduced the maize and the milpa, an itinerant maize-based slash-and-burn polyculture, which depends on revegetation to re-establish soil fertility. Also, the milpa is a most important pre-Hispanic legacy, a biocultural and landrace reservoir actively affecting landscape configuration, succession, soil development, and the genetic architecture of the species. Unprecedented human epidemics and soil, biodiversity, and culture erosion followed behind the Spanish aftermath and the subsequent globalization. > 63 million people and ≈100 ethnic groups inhabit SMP in 2020, which, with the biota, share the same problems of climate change, disturbance, and acculturation. SMP has been the scenario of severe climate change, fastest and deadliest extinction events (amphibians), a most spectacular exotic-species invasion (Africanized honeybees), and accelerated deforestation, defaunation, and acculturation. Biocultural conflicts between native and non-native people are globalization byproducts and sources of habitat destruction and species decline. Bottom-up initiatives are likely the best option for conservation in indigenous areas, whereas honest (i.e., with truly conservation intentions) top-down initiatives are helpful if the affected people are considered subjects (no objects) of conservation plans. We suggest some unique areas requiring conservation attention and analyzed current conservation initiatives. Not a single initiative is best suited for all conservation needs in SMP. Protection of all successional stages is critical for resilience and revegetation. Conservation of the milpa system (crop fields and subsequent fallows) is an optimal option for minimizing tradeoffs between conservation and people needs and safeguarding traditional culture and local landraces but is limited to areas with indigenous people and may not work for species with large home ranges.

Aim: Planted forests are becoming increasingly common world‐wide for a variety of reasons, including water conservation and carbon sequestration, although the effects of tree plantations on biodiversity are unclear with respect to whether planted ecosystems are "green deserts" or valuable habitats for biodiversity. Location: Global. Time period: 1980–2020. Taxa studied: Flora, fauna and microorganisms. Methods: By conducting a meta‐analysis of 361 observations from 138 sites world‐wide, we explored the global patterns and associated drivers of biodiversity responding to tree plantations by comparing biodiversity levels in plantations and adjacent habitats (primary or secondary forests). Results: Overall, the biodiversity (species richness) and abundance across multitrophic levels in tree plantations were lower than those in primary forests, reached similar values to secondary succession, but varied with plantation and management regimes. Specifically, the biodiversity across multitrophic levels in reforestation was higher than that in afforestation; the biodiversity in mixed, native species and unmanaged plantations was higher than that in monoculture, exotic species and managed plantations. The diversity of vertebrates, invertebrates and plants in reforestation was lower than that in primary forests, whereas belowground biodiversity in reforestation showed no difference from primary forests. Invertebrate diversity in reforestation was lower than that in secondary succession, whereas plant diversity was higher than that in secondary succession. Moreover, the biodiversity in reforestation increased with reforestation age. Furthermore, structural equation models showed that aboveground faunal diversity in reforestation was driven by canopy coverage and plant diversity and that reforestation affected belowground biodiversity mainly by changing soil organic carbon. Main conclusions: Our findings suggest that reforestation by planting mixed native species will be more beneficial to biodiversity. We reveal that biodiversity in intensively managed plantations is significantly lower than that in restoration‐oriented plantations. We highlight that primary forests are not replaceable, but that planted forests might be a reliable way to restore biodiversity rapidly. [ABSTRACT FROM AUTHOR]

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Jays Garrulus glandarius play a major role in the synzoochorous dispersal of oaks in Europe, including Poland. Oaks have sprung up from acorns cached by jays not only in woodlands but also on meadows, pastures and fallow land. There are no reports as yet of acorn caching by these birds in orchards. This paper describes synzoochorous regeneration in orchards and attempts to evaluate its effect on the farming landscape. The research material was gathered from an area of 1.85 ha of fallow land in orchards (Poland, 51°41.712′N – 20°42.244′E). As a site for caching acorns, jays exhibited a preference for sour cherry orchards. The pedunculate oaks Quercus robur growing in these orchards were in very good condition. They may constitute a reservoir of good seeding material, which will also assist in the regeneration of the woodlands in the vicinity. [ABSTRACT FROM AUTHOR]

Succession is a basic natural process of ecosystem recovery, it may start completely de novo (primary succession) or after serious disturbance of the previous ecosystem (secondary succession). Despite most reclamation and restoration approaches depending on it and despite extensive previous research, we found no worldwide review that would describe the pattern of vegetation cover and woody vegetation recovery in individual types of succession and explore major factors that affect the speed of vegetation recovery. To fill this gap we have searched world literature and extracted data about 244 succession series about total vegetation cover and 113 about woody vegetation cover. The rate of vegetation cover recovery is significantly slower during primary succession than during secondary succession, this however not apply to woody vegetation. The type of disturbance affects the speed of recovery, post‐mining sites recover fastest among primary succession and older fields were the fastest among secondary succession, the slowest one being succession in glacier retreats. Latitude, soil pH, the size of the disturbed area, temperature, and actual evapotranspiration affect the rate of vegetation recovery in primary succession, while only latitude affects secondary succession. Some other factors affect succession after a specific disturbance. The study shows that succession can be an effective tool to restore vegetation cover and woody vegetation on many occasions. We expect that differences in the nutrient availability determine differences in the rate of total vegetation cover recovery, while soil porosity (compaction) may be an important factor affecting woody vegetation recovery. [ABSTRACT FROM AUTHOR]

Growth in individual size or biomass is a key demographic component in population models, with wide‐ranging applications from quantifying species performance across abiotic or biotic conditions to assessing landscape‐level dynamics under global change. In forest ecology, the responses of tree growth to biotic interactions are widely held to be crucial for understanding forest diversity, function, and structure. To date, most studies on plant–plant interactions only examine the additive competitive or facilitative interactions between species pairs; however, there is increasing evidence of non‐additive, higher‐order interactions (HOIs) impacting species demographic rates. When HOIs are present, the dynamics of a multispecies community cannot be fully understood or accurately predicted solely from pairwise outcomes because of how additional species "interfere" with the direct, pairwise interactions. Such HOIs should be particularly prevalent when species show non‐linear functional responses to resource availability and resource‐acquisition traits themselves are density dependent. With this in mind, we used data from a tropical secondary forest—a system that fulfills both of these conditions—to build an ontogenetic diameter growth model for individuals across 10 woody‐plant species. We allowed both direct and indirect interactions within communities to influence the species‐specific growth parameters in a generalized Lotka–Volterra model. Specifically, indirect interactions entered the model as higher‐order quadratic terms, i.e., non‐additive effects of conspecific and heterospecific neighbor size on the focal individual's growth. For the whole community and for four out of 10 focal species, the model that included HOIs had more statistical support than the model that included only direct interactions, despite the former containing a far greater number of parameters. HOIs had comparable effect sizes to direct interactions, and tended to further reduce the diameter growth rates of most species beyond what direct interactions had already reduced. In a simulation of successional stand dynamics, the inclusion of HOIs led to rank swaps in species' diameter hierarchies, even when community‐level size distributions remained qualitatively similar. Our study highlights the implications, and discusses possible mechanisms, of non‐additive density dependence in highly diverse and light‐competitive tropical forests. [ABSTRACT FROM AUTHOR]

Questions: Post‐fire seeding has been widely implemented in the semiarid Great Basin because natural vegetation recovery may be compromised. Non‐native species are often seeded to rapidly establish perennial cover and compete with invasive annuals. We asked whether seeding treatments with different amounts of native and non‐native species followed different successional trajectories and whether they became more similar to reference communities over time. We considered restoration implications of seed mix choices and reference community options involving: (a) local unburned vegetation; and (b) reference states mapped by the USDA Natural Resources Conservation Service (NRCS) based on soil–vegetation associations. Location: Tintic Valley, UT, USA. Methods: Four post‐fire seeding treatments differing by seed mix were installed alongside an unseeded control (USC) at two sites. Two seed mixes were comprised of native species and two were predominantly non‐native. Vegetation was monitored 1–3 and 16–18 years after fire and seeding. Reference communities were characterized and compared using hierarchical clustering. Non‐metric multidimensional scaling and permutation tests were used to determine successional trajectories of post‐fire treatments in relation to reference communities. Results: Local unburned reference communities had fewer herbaceous perennials and higher woody cover than NRCS reference communities, suggesting departure from conditions expected under minimal post‐settlement disturbance. USCs became more similar to reference communities over time, though less so at a site with abundant invasive annuals. Trajectories of seeded treatments were driven by seed mix species, with native‐only mixes approaching reference communities more closely than mixes with non‐natives. Conclusions: Gradual recovery of reference community composition is possible without seeding but the degree and rate of recovery can vary by site. Seeding can accelerate perennial vegetation recovery but may result in alternative successional trajectories, especially if non‐native species are seeded. Carefully selected reference communities can serve as guides for formulating seed mixes when restoration of natural vegetation is desired. [ABSTRACT FROM AUTHOR]

Successful colonization and growth of trees within herbaceous communities may result from different interactions with the herbaceous community. First, colonizing trees compete against larger, established herbs, while subsequent growth occurs among similarly sized or smaller herbs. This shift from colonization to growth may lead three drivers of community dynamics—nutrients, consumers, and herbaceous diversity—to differentially affect tree colonization and, later, tree performance. Initially, these drivers should favor larger, established herbs, reducing tree colonization. Later, when established trees can better compete with herbs, these drivers should benefit trees and increase their performance. In a 4-year study in a southeastern US old field, we added nutrients to, excluded aboveground consumers from, and manipulated initial richness of, the herbaceous community, and then allowed trees to naturally colonize these communities (from intact seedbanks or as seed rain) and grow. Nutrients and consumers had opposing effects on tree colonization and performance: adding nutrients and excluding consumers reduced tree colonization rate, but later increased the size of established trees (height, basal diameter). Adding nutrients and excluding consumers also restricted tree colonization to earlier years of study, which partially explained the effect of nutrient addition on plant size. Together, this shows differing impacts of nutrients and consumers: factors that initially limited tree colonization also resulted in larger established trees. This suggests that succession of grasslands that are either eutrophied or have diminished consumer pressure may experience lags and pulses in woody encroachment, leading to an extended period of herbaceous dominance followed by accelerated woody growth. [ABSTRACT FROM AUTHOR]

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As tropical deforestation and forest degradation accelerate, carbon-credit trading could provide a financial incentive to preserve and regenerate forests. Since carbon trading relies on the accurate quantification of carbon stocks, allometric equations are urgently needed to derive above-ground dry biomass (AGB) from easily measured variables. Few allometric equations have been published for regenerating secondary forests in Southeast Asia. This study established new allometric equations, to determine AGB and carbon in regenerating secondary forests on shifting cultivation fallows in northern Thailand. To develop the equations, data were collected from 78 trees (136 felled individual stems, including coppices) ranging in size from 1 to 32.9 cm diameter at breast height (D). The dependent variable was AGB. The independent variables were D, tree height (H) and wood density (WD). Wood density varied significantly among species (p < 0.05). Consequently, including WD in the function D2H × WD predicted AGB most accurately, compared with other functions that excluded it. Mean carbon concentration in stems, branches, and leaves was 44.84% ± 1.63 of dry mass, but it varied significantly among tree species (p < 0.05). The new allometric equation revealed that tree ABG was highest in secondary forest, followed by the 7-year-fallow and the 4-year-fallow: 105.3, 38.3 and 10.3 Mg ha−1, respectively, while above-ground carbon was 47.7, 17.4, and 4.6 Mg C ha−1, respectively. Natural regeneration accumulated carbon slower than reported for active restoration, suggesting that managed restoration is preferable to passive regeneration on fallows in northern Thailand. The allometric equations, derived from this study, can be used to accurately determine tree ABG and carbon storage in regenerating secondary forest, with higher precision than has hitherto been possible, thus satisfying the monitoring requirements of REDD+ and other carbon-trading schemes. [ABSTRACT FROM AUTHOR]

One-third of all Neotropical forests are secondary forests that regrow naturally after agricultural use through secondary succession. We need to understand better how and why succession varies across environmental gradients and broad geographic scales. Here, we analyze functional recovery using community data on seven plant characteristics (traits) of 1,016 forest plots from 30 chronosequence sites across the Neotropics. By analyzing communities in terms of their traits, we enhance understanding of the mechanisms of succession, assess ecosystem recovery, and use these insights to propose successful forest restoration strategies. Wet and dry forests diverged markedly for several traits that increase growth rate in wet forests but come at the expense of reduced drought tolerance, delay, or avoidance, which is important in seasonally dry forests. Dry and wet forests showed different successional pathways for several traits. In dry forests, species turnover is driven by drought tolerance traits that are important early in succession and in wet forests by shade tolerance traits that are important later in succession. In both forests, deciduous and compound-leaved trees decreased with forest age, probably because microclimatic conditions became less hot and dry. Our results suggest that climatic water availability drives functional recovery by influencing the start and trajectory of succession, resulting in a convergence of community trait values with forest age when vegetation cover builds up. Within plots, the range in functional trait values increased with age. Based on the observed successional trait changes, we indicate the consequences for carbon and nutrient cycling and propose an ecologically sound strategy to improve forest restoration success. [ABSTRACT FROM AUTHOR]

Wildflower strips (WFS) are amongst the most commonly applied measures to promote pollinators and natural enemies of crop pests in agroecosystems. Their potential to enhance these functionally important insect groups may vary substantially with time since establishment of WFS. However, knowledge on their temporal dynamics remains scarce, hampering recommendations for optimized design and management. We therefore examined temporal dynamics of taxonomic and functional groups of bees and hoverflies in perennial WFS ranging from one to ≥6 years since sowing with a standardized species-rich seed mixture of flowering plants in 18 agricultural landscapes in Switzerland. The abundance of wild bees, honeybees and hoverflies declined after the second year by 89%, 62% and 72%, respectively. Declines in bee abundance and hoverfly species richness were linear and those of aphidophagous hoverflies exponential, while wild bee species richness peaked in the third year. Declines over time generally paralleled decreases in flower abundance (-83%) and flowering species richness (-61%) and an increase in grass cover (+70%) in WFS. Flowering plant species richness showed strong positive relationships with dominant crop-visiting wild bees and aphidophagous hoverflies. Furthermore, dominant crop-visiting wild bees, but not aphidophagous hoverflies, were positively related to the proportion of (semi-)open semi-natural habitat in the surrounding landscape (500 m radius), but negatively with forest. We conclude that the effectiveness of perennial WFS to promote pollinator diversity, crop-pollinating bees and aphidophagous hoverflies through foraging resources decreases after the first two to three years, probably due to a decline of diverse and abundant floral resources. Although older perennial WFS may still provide valuable nesting and overwintering opportunities for pollinators and natural enemies, our findings indicate that regular re-sowing of perennial WFS may be necessary to maintain adequate floral resource provisioning for effective pollinator conservation and promotion of crop pollination and natural pest control services in agricultural landscapes. [ABSTRACT FROM AUTHOR]

Summary: Establishment and growth of grassland plant species is generally promoted by arbuscular mycorrhizal fungi (AMF) when grown in isolation. However, in grassland communities AMF form networks that may connect individual plants of different ages within and between species. Here, we use an ingrowth core approach to examine how mycorrhizal networks influences performance of seedlings in grasslands.We selected four grass and four forb species with known negative or neutral‐positive plant–soil feedback and grew them individually in steel mesh cores filled with living field soil. Cores were placed in six restored grasslands, three grasslands were of relatively young and three were of older successional age.Ingrowing mycorrhizal fungal hyphae were severed twice a week in half of all cores, which resulted into reduced AMF colonization and increased seedling biomass, irrespective of the fields' succession stage, and the plants' grass/forb group, or plant–soil feedback type. In the control cores, root colonization by AMF was negatively correlated to seedling biomass, whereas there was no such relationships in the cores that had been lifted.We conclude that connections to arbuscular mycorrhizal networks of surrounding plants had a negative impact on biomass of establishing forb and grass seedlings. [ABSTRACT FROM AUTHOR]

Aims: We studied the regeneration dynamics of woodlands and abandoned old fields in a landscape dominated by Quercus suber in its lower limits of rainfall and temperature. Two hypotheses were established: (1) regeneration of Quercus species is strongly favored by the presence of tree cover; and (2) growth of Q. suber is driven by the climatic variables that represent the lower ecological limit of its leading distribution edge. Methods: We selected woodlands and old fields with and without tree remnants (n = 3 per type), and analyzed stand structure, soil parameters and tree growth. Results: Succession was arrested in old fields without tree remnants. By contrast, remnant trees were accelerators of forest recovery in old fields. Tree cover played a fundamental role in Quercus recruitment throughout seed dispersal and facilitation that mitigate the effects of summer drought on seedlings. Also, tree cover improved soil parameters (e.g., organic matter) that are important factors for understanding differences in regeneration. Winter/spring precipitation exerted a positive effect on tree growth, as well as temperatures during winter/spring and September. Conclusions: Regeneration dynamics are modeled by the density of tree cover in the cold and dry edge of the distribution area of Q. suber where Q. ilex is increasing in abundance. Although temperature has a positive effect on the tree growth of Q. suber, when demographic processes are considered, decreases in water availability likely play a critical role in Q. ilex recruitment. This in turn changes dominance hierarchies, especially in abandoned areas with little or no tree cover. [ABSTRACT FROM AUTHOR]

Naturally regenerated forests have been shown to achieve the level of species richness similar to old-growth forests in several decades, but a much longer time is required for them to regain the species composition and structural complexity of typical old-growth forests (Aide et al., 2000; Brown & Lugo, 1990). A culture of conservation: How an ancient forest plantation turned into an old-growth forest reserve - The story of the Wamulin forest Keywords: biodiversity; ecosystem services; old-growth forest; secondary succession; unity between humans and the nature; Wanmulin Nature Reserve EN biodiversity ecosystem services old-growth forest secondary succession unity between humans and the nature Wanmulin Nature Reserve 1014 1024 11 10/11/21 20211001 NES 211001 INTRODUCTION Forest plantations are an important component of global forest cover with a global extent of 294 million ha (FAO, 2020). Thus, it is unwise to interpret the example of the Wanmulin Nature Reserve to claim that forest plantations are ecologically and culturally as valuable as old-growth forests, because it is the multiple centuries of natural succession without human disturbance, not the establishment of forest plantation, that contributes most to the high levels of ecosystem services found in the Wanmulin Nature Reserve. [Extracted from the article]

With large tracts of Tropical Dry Forests (TDF) in the Americas previously deforested, many places are currently undergoing secondary ecological succession. These processes vary in time and space, creating a landscape with forests of different ages or successional stages. These secondary forests need moreneed more understanding about how their ecosystem functionality is restored and recovering along the succession path. In particular, it is poorly understood how different successional stages moderate extremes of Essential Climatic Variables (ECV) such as temperature, relative humidity, soil moisture, and the fraction of Absorbed Photosynthetic Active Radiation (f APAR). This paper, therefore, studies the linkages between high temporal resolution tower-based optical canopy phenology time series and seasonal changes in local ECV conditions between early (10–12 years) and late (50+ years) successional stage TDF in southeastern Brazil. We compare diurnal and seasonal patterns of understory ECVs between early/late plots and investigate the canopy's Climate Moderating Capacity (CMC). Our data indicate at least 100 mm of precipitation within two weeks is necessary to initiate leaf flushing in this TDF. We also find that soil moisture and daytime air humidity strongly correlate (R2 > 0.75) with seasonal patterns in canopy vegetation greenness indices and f APAR with a cross-correlation time lag peak of 12–15 days. Our results suggest that the late stage is more effective at cooling (−1.4 ± 0.6 °C vs −0.8 ± 0.6 °C) and reducing daytime evaporation (−0.41 ± 0.2 kPa vs −0.18 ± 0.12 °C) in the understory during the growing season than the early stage. Results suggest that the CMC varies with seasonal canopy leaf area dynamics and with heat and moisture scales, becoming significantly stronger when temperatures and vapour pressure deficits were highest, and correlated strongly with canopy f APAR dynamics (R2 = 0.82). These findings demonstrate that TDFs can effectively regain microclimatic buffering capacity. • The study focuses on how early and late successional stages of TDFs restore ecosystem functionality. • Late succession TDFs are more efficient in cooling and reducing daytime evapotranspiration than early succession TDFs. • There is a strong correlation between canopy vegetation greenness indices and seasonal ECVs patterns. • The microclimatic buffering capacity of TDFs is a complex interplay of seasonal leaf area dynamics and climatic conditions. [ABSTRACT FROM AUTHOR]

• Turnover dominated β-diversity changes in karst forest. • The impact of stochastic processes on β-diversity is more significant. • Topographical factors influence the β-diversity more compared with soil nutrients. β-diversity usually refers to species turnover along a gradient or changes in species diversity between communities. It is a key concept in understanding the mechanisms of biodiversity pattern formation. However, the component dependence and the driving factors of β-diversity during natural restoration remain unclear. In this study, a series of forest dynamic plots (FDPs) were established through the natural restoration stages in degraded karst forests, including the shrub-canopy mixed forest stage (SC), the secondary-growth forest stage (SG), and the old-growth forest stage (OG). After comparing species composition during natural restoration and its dependence on species turnover and nestedness, it was found that natural restoration significantly influenced the species composition by altering the species turnover in degraded karst forests rather than the nestedness. The contribution of turnover to β-diversity gradually increased, while the contribution of nestedness decreases gradually. Furthermore, the PER-SIMPER method was used to quantify the first-order assembly process that drives variations in species composition during restoration stages. To identify the factors influencing β-diversity, both variation partitioning analysis and a random forest model were employed. The results suggested that differences in species compositions across restoration stages were mainly driven by stochastic processes, and the deterministic processes were strengthened during the natural restoration. In addition, topographic factors contributed more to β-diversity than soil nutrient factors. This study highlighted changes in component dependence of degraded karst forests during natural restoration and emphasized the importance of a more comprehensive framework in assessing the restoration of degraded forest ecosystems. More attention should be paid to topographic structure in understanding biodiversity patterns, especially in highly heterogeneous forest ecosystems. [ABSTRACT FROM AUTHOR]

Abandonment of agricultural lands in recent decades is occurring mainly in Europe, North America and Oceania, and changing the fate of landscapes as the ecosystem recovers during fallow stage. The objective of this study was to find the impact of secondary succession in abandoned fields on some parameters of acidic sandy soils in the Borská nížina lowland (southwestern Slovakia). We investigated soil chemical (pH and soil organic carbon content), hydrophysical (water sorptivity, and hydraulic conductivity), and water repellency (water drop penetration time, water repellency cessation time, repellency index, and modified repellency index) parameters, as well as the ethanol sorptivity of the studied soils. Both the hydrophysical and chemical parameters decreased significantly during abandonment of the three investigated agricultural fields. On the other hand, the water repellency parameters increased significantly, but the ethanol sorptivity did not change during abandonment. As the ethanol sorptivity depends mainly on soil pore size, the last finding could mean that the pore size of acidic sandy soils did not change during succession.

The aim of this study is to differentiate old-field plant communities along the abandonment time and/or environmental gradient in the landscape surrounded villages with established Czech settlers in Romanian Banat area conserving traditional agriculture, and to identify site factors which cause plant diversity of particular vegetation types. Study area: Wider territory centered by the village Sfânta Elena, southern Romania ((44°40’ N; 21°43’ E). Methods: We collected 97 phytosociological relevés covered the same number of old-fields in the area and the following habitat parameters were measured: soil pH, available phosphorus, total carbon and nitrogen, Heat Load Index. Software TURBOVEG / JUICE was used to collect and elaborate the data set of relevés. Old-field vegetation was classified into five basic plant communities using TWINSPAN (all the botanical material includes 291 plant species). For each community, we detected diagnostic species according to their fidelity index. The presence of mowing, grazing or burning was registered for recorded stands. Ecological preferences of each community were examined using one-way analysis of variance (ANOVA). Vegetation-environment relationships were analysed using ordination method – Cannonical correspondence analysis (CCA) in CANOCO for Windows (version 4.5) to find the main variability gradients within the dataset. Scatter plot relationships between variables were constructed. Main results and conclusions: Dependence of number of species (alpha diversity) on the abandoned field’s age exhibits an unimodal shape of this relationship with the maximum peak of species diversity in plant stands aged approximately 13 years. The most importnat ecological factors and/or type of management in the relationship to the old-field plant composition show the following significance order: available phosphorus content in the soil (P), total nitrogen content in the soil (N), presence of burning, length of abandonment (old-field age), carbon/nitrogen ratio in the soil (C/N). Other parameters (grazing, mowing, zero management) do not demonstrate effective impact according to our dataset and seem to be equal to the absence of burning.

Abstract Background This study aimed to determine the influence of soil traits, vegetation structure and climate on litterfall dynamics along a successional gradient in a tropical dry forest (TDF) in southeastern Brazil. We used a chronosequence design consisting of three successional stages (early, intermediate, and old-growth) defined based on forest age and vertical and horizontal structures. Methods Litterfall was recorded monthly for three years in 12 plots of 50 × 20 m (four plots per stage) where vegetation parameters (species richness, basal area, density and height for trees with diameter at breast height ≥ 5 cm) and soil chemical and physical traits were previously obtained. We placed eight 0.5-m2 litter traps in each plot, totalling 96 traps. Samples were sorted into leaves, twigs, reproductive parts, and debris. Results Litterfall mass was composed mainly of leaves and varied slightly among years (4 to 4.5 Mg∙ha− 1), within the range observed for other TDFs. Annual litterfall mass was higher at the old-growth forest than at the early and intermediate forest stages and this successional pattern was driven by vegetation characteristics (forest structural parameters and plant functional groups) and soil traits related to water-holding capacity. Litter amount in the intermediate stage was lower than expected for its forest structure (and similar to the early stage), possibly because its higher soil clay content increased the water holding capacity and leaf retention during the dry season. Seasonal variations in monthly litterfall were strongly driven by forest deciduousness and affected by climatic factors related to water availability. This pattern was consistent across the successional gradient, although differences for each litterfall component were observed. Conclusions Our results suggest that litter production in the studied TDF is influenced by multiple factors along succession, such as above-ground biomass and the degree of leaf retention mediated by soil water-holding capacity. Further studies on community phenological patterns can allow a better understanding of successional changes on litterfall and how fast this fundamental function recovers in secondary forests.

Abstract The Mediterranean region is recognized as a global biodiversity hotspot. However, over the last decades, the cessation of traditional farming in the north part of the Mediterranean basin has given way to strong afforestation leading to occurrence of abandoned agricultural lands colonized by pioneer expansionist species like Pinus halepensis. This pine species is known to synthesize a wide range of secondary metabolites, and previous studies have demonstrated strong allelopathic potentialities of its needle and root leachates. Pinus halepensis is also recognized to release significant amounts of volatile organic compounds (VOC) with potential allelopathic effects that have never been investigated. In this context, the objectives of the present study were to improve our knowledge about the VOC released from P. halepensis needles and roots, determine if these VOC affect the seed germination and root growth of two herbaceous target species (Lactuca sativa and Linum strictum), and evaluate if soil microorganisms modulate the potential allelopathic effects of these VOC. Thirty terpenes were detected from both, needle and root emissions with β‐caryophyllene as the major volatile. Numerous terpenes, such as β‐caryophyllene, δ‐terpinene, or α‐pinene, showed higher headspace concentrations according to the gradient green needles

Polygraphus proximus Blandford is a bark beetle that has recently invaded the dark coniferous forests of Southern Siberia. Over the last decade, this four-eyed fir bark beetle has destroyed Abies sibirica Ledeb stands on more than 500 thousand hectares. This study considers the initial stages of natural reforestation, which can define the restorative succession scenario for completely dead forest stands after the outbreak fades. Areas disturbed by outbreaks have a strong potential for natural coniferous regeneration when the young generation of Abies sibirica dominates in species composition. As early as 5 years after the outbreak, a successful, sufficient for the future forest formation, young generation density (13,000 trees/ha) is observed. Intensive undergrowth development is noted. The high density of young stands in some areas ensures the canopy closure and forms a shady ground cover vegetation type. At the same time, in some disturbed areas there are threats to undergrowth. In open places with thin undergrowth, a considerable amount of forest fuels represented by large wood residues and dead grass accumulates and can cause high-intensity fire emergence and development. Another risk is human activity. In former outbreak foci, where clear-cutting was implemented, healthy trees were cut down and the existing young coniferous generation was destroyed. To date, clearings have been overgrown with secondary species (Betula pendula Roth., Populus tremula L.). Ground cover communities have transformed into open-type phytocenosis where cereal grasses prevail. This has led to turfing and significant litter and dry grass accumulation. To sum up, in faded Polygraphus proximus outbreak areas, strong young forest generation ensures reforestation without dominant species change. To reduce risks of species change and conserve valuable Abies sibirica species, it is necessary to strengthen wildfire protection.

Questions: Human disturbance is increasingly affecting forest dynamics across the tropics. Forests can recover via natural secondary succession to pre‐disturbance levels of biodiversity, species composition, and ecosystem carbon stocks. Central Africa will be subject to increasingly high shifting‐cultivation pressure in the next decades, but succession trajectories of these ecosystem properties are still poorly known for the Congo basin. We addressed two questions: (1) how does taxonomic and functional composition and diversity shift during secondary succession; and (2) how fast do above‐ground carbon stocks recover during secondary succession in tropical forests? Location: Central Congo basin. Methods: We conducted an inventory of trees (diameter at breast height [DBH] ≥ 10 cm), measured species traits and soil texture and carbon content in 18 plots, located along six secondary succession stages (i.e., from agricultural to old growth forest sites). We measured tree diameter, height for 20% of trees distributed across diameter classes, wood traits from all species, and leaf traits from species that contributed to 85% of the plot basal area. Results: We showed that secondary forests recover relatively fast in terms of tree species diversity, alpha functional diversity, and fine‐root carbon, with near‐old‐growth forest values after six decades past disturbance, while floristic composition exhibited slower recovery. Secondary forests only partially shifted from acquisitive to a conservative life history, with shifts in leaf traits being largely decoupled from wood traits. Only 43% of above‐ground carbon recovered after 60 years of forest regrowth, potentially through a slow recovery of the large‐sized tree stems that dominate carbon stocks of old‐growth forests. Conclusions: Our findings underline the capacity of Afrotropical forests to recover species and alpha functional diversity after clear‐cutting through shifting cultivation. Simultaneously, old‐growth forests harbor a particular floristic community and store a large quantity of carbon with much longer recovery trajectories, stressing the need for conservation of these forests in the Congo basin. [ABSTRACT FROM AUTHOR]

Identifying generalisable processes that underpin population dynamics is crucial for understanding successional patterns. While longitudinal or chronosequence data are powerful tools for doing so, the traditional focus on community‐level shifts in taxonomic and functional composition rather than species‐level trait–demography relationships has made generalisation difficult. Using joint species distribution models, we demonstrate how three traits—photosynthetic rate, adult stature, and seed mass—moderate recruitment and sapling mortality rates of 46 woody species during secondary succession. We show that the pioneer syndrome emerges from higher photosynthetic rates, shorter adult statures and lighter seeds that facilitate exploitation of light in younger secondary forests, while 'long‐lived pioneer' and 'late successional' syndromes are associated with trait values that enable species to persist in the understory or reach the upper canopy in older secondary forests. Our study highlights the context dependency of trait–demography relationships, which drive successional shifts in sapling's species composition in secondary forests. [ABSTRACT FROM AUTHOR]

Current restoration protocols for roadside cut slopes in South Korea involve hydroseeding with exotic species to achieve early greening and soil stabilization. However, exotic species can negatively affect adjacent native ecosystems. This study investigated the functional traits of early colonizers in slope restoration and surrounding environments to inform restoration methods that generate similar communities as those of native ecosystems. Slope vegetation (species density, species cover, upperstory species, canopy cover) and environment (aspect, angle, soil properties) were surveyed from the road edge to the forest boundary, and were classified as three distinct zones: a hydroseeded slope, a transition zone, and the forest edge. Naturally occurring species were classified into functional groups to examine dominant traits during early colonization. Hemicryptophyte or geophyte forest species and forest interior woody species were well established and dominant in transition zones and cut slopes. Potential native species for slope restoration can be identified by examining functional group species in the adjacent forest. These native species can achieve restoration goals and block invasive species in the same functional group. Festuca arundinacea (tall fescue), which is reported as an invasive alien species, rapidly spread after introduction for restoration. Thus, continuous monitoring for impact on native communities is required after sowing invasive alien species. Future slope restoration should consider native woody species and perennial forest sedge species that develop rhizomes, and reconsider the use of tall fescue. This study indicates that cut slopes can be appropriately managed to enhance the quality of habitats for native species. [ABSTRACT FROM AUTHOR]

Light is a key resource for tree performance and hence, tree species partition spatial and temporal gradients in light availability. Although light distribution drives tree performance and species replacement during secondary forest succession, we yet lack understanding how light distribution changes with tropical forest development.This study aims to evaluate how changes in forest structure lead to changes in vertical and horizontal light heterogeneity during tropical forest succession.We described successional patterns in light using a chronosequence approach in which we compared 14 Mexican secondary forest stands that differ in age (8–32 years) since agricultural abandonment. For each stand, we measured vertical light profiles in 16 grid cells, and structural parameters (diameter at breast height, height and crown dimensions) for each tree.During succession, we found a rapid increase in stand size (basal area, crown area and length) and stand differentiation (i.e. a gradual leaf distribution along the forest profile), which leads to fast changes in light conditions and more light heterogeneity. The inflection points of the vertical light gradient (i.e. the absolute height at which 50% relative light intensity is attained) rapidly moved towards higher heights in the first 20 years, indicating that larger amounts of light are intercepted by canopy trees. Light attenuation rate (i.e. the rate of light extinction) decreased during succession due to slower accumulation of the crown area with height. Understorey light intensity and heterogeneity slightly decreased during succession because of an increase in crown size and a decrease in lateral gap frequency. Understorey relative light intensity was 1.56% at 32 years after abandonment.Synthesis. During succession, light conditions changed linearly, which should lead to a continuous and constant replacement of species. Especially in later successional stages, stronger vertical light gradients can limit the regeneration of light‐demanding pioneer species and increase the proportion of shade‐tolerant late‐successional species under the canopy. These changes in light conditions were largely driven by the successional changes in forest structure, as basal area strongly determined the height where most light is absorbed, whereas crown area, and to a lesser extent crown length, determined light distribution. [ABSTRACT FROM AUTHOR]