Forest Diversity Research Articles

Using long‐term tree diversity experiments to explore the mechanisms of temporal shifts in forest ecosystem functioning

Plant diversity is known to influence ecosystem functioning, but the strength and direction of this relationship vary considerably among studies, most of which have a short duration. In communities with long‐lived species, such as forests, traits of individual trees change from seedlings to maturity, and the environment in which trees grow also continually changes through stand development and forest succession. We argue that interactions between these individual and community‐level effects over time will alter biodiversity‐ecosystem functioning (BEF) relationships, likely explaining at least part of the reported variation in BEF effects among studies. We outline a series of mechanisms through which temporal changes at the tree and stand levels can alter BEF relationships and illustrate these processes using data from the long‐term Satakunta forest diversity experiments in Finland. We argue that long‐term forest diversity experiments are essential to robustly characterize temporal dynamics emerging from the complex interplay between plant functional traits and environmental conditions over time. These experiments can provide critical insights for predicting the consequences of biodiversity loss on ecosystem functioning and service provisioning over time.

Floodplain forests drive fruit-eating fish diversity at the Amazon Basin-scale

Unlike most rivers globally, nearly all lowland Amazonian rivers have unregulated flow, supporting seasonally flooded floodplain forests. Floodplain forests harbor a unique tree species assemblage adapted to flooding and specialized fauna, including fruit-eating fish that migrate seasonally into floodplains, favoring expansive floodplain areas. Frugivorous fish are forest-dependent fauna critical to forest regeneration via seed dispersal and support commercial and artisanal fisheries. We implemented linear mixed effects models to investigate drivers of species richness among specialized frugivorous fishes across the ~6,000,000 km2 Amazon Basin, analyzing 29 species from 9 families (10,058 occurrences). Floodplain predictors per subbasin included floodplain forest extent, tree species richness (309,540 occurrences for 2,506 species), water biogeochemistry, flood duration, and elevation, with river order controlling for longitudinal positioning along the river network. We observed heterogeneous patterns of frugivorous fish species richness, which were positively correlated with floodplain forest extent, tree species richness, and flood duration. The natural hydrological regime facilitates fish access to flooded forests and controls fruit production. Thus, the ability of Amazonian floodplain ecosystems to support frugivorous fish assemblages hinges on extensive and diverse seasonally flooded forests. Given the low functional redundancy in fish seed dispersal networks, diverse frugivorous fish assemblages disperse and maintain diverse forests; vice versa, diverse forests maintain more fish species, underscoring the critically important taxonomic interdependencies that embody Amazonian ecosystems. Effective management strategies must acknowledge that access to diverse and hydrologically functional floodplain forests is essential to ensure the long-term survival of frugivorous fish and, in turn, the long-term sustainability of floodplain forests.

From division to 'divergence': to understand wood growth across timescales, we need to (learn to) manipulate it.

Wood formation is the Rosetta stone of tree physiology: a traceable, integrated record of physiological and morphological status. It also produces a large and persistent annual sink for terrestrial carbon, motivating predictive understanding. Xylogenesis studies have greatly expanded our knowledge of the intra-annual controls on wood formation, while dendroecology has quantified the environmental drivers of multi-annual variability. But these fields operate on different timescales, making it challenging to predict how short (e.g. turgor) and long timescale processes (e.g. disturbance) interactively influence wood formation. Toward this challenge, wood growth responses to natural climate events provide useful but incomplete explanations of tree growth variability. By contrast, direct manipulations of the tree vascular system have yielded unexpected insights, particularly outside of model species like boreal conifers, but they remain underutilized. To improve prediction of global wood formation, we argue for a new generation of experimental manipulations of wood growth across seasons, species, and ecosystems. Such manipulations should expand inference to diverse forests and capture inter- and intra-specific differences in wood growth. We summarize the endogenous and exogenous factors influencing wood formation to guide future experimental design and hypotheses. We highlight key opportunities for manipulative studies integrating measurements from xylogenesis, dendroanatomy, dendroecology, and ecophysiology.

Bryophytes as Indicators of Disturbance in One of the Last Remnants of the Mountain Forests of El Oro Province, Ecuador

Epiphytic bryophytes are an important component in terms of the diversity and functioning of montane forests known as biodiversity hotspots. Bryophytes are highly dependent on their external environments because they are sensitive to environmental changes related to disturbance, fragmentation, air pollution, and climate change. The richness and composition of bryophytes in remnants of primary and secondary forests were analyzed, where the richness and cover were recorded on trunk bases of 120 trees. Changes in species richness and diversity were analyzed using generalized linear models (GLMs), and changes in species composition, using multivariate analysis. A total of 57 bryophyte species (36 liverworts and 21 mosses) were recorded in trunk bases. For the first time, 19 new liverworts for the province of El Oro are reported. The richness and diversity of bryophyte species decrease in disturbed forests when compared to primary forests, with a marked decrease in species less adapted to conditions of high light (shade epiphytes). In the same line, species composition is different in each type of forest, where bryophytes with high humidity requirements were abundant in primary forests. This study confirms that forest disturbance is a key factor in determining not only the number of species but also the composition of bryophyte species. The maximum tree diameter and primary forest remnants are important factors in the conservation of sensitive bryophyte species at the base of trees in one of the last remnants of mountain forests in El Oro Province, Ecuador.

Two decades of arthropod biodiversity after windthrow show different dynamics of functional groups

Abstract Windthrow disturbance is an important driver of arthropod diversity in forests. In the past, studies have mainly focused on the first years after disturbance, and there are hardly any data on arthropod trajectories in windthrows and on salvage logging effects over decades. We sampled arthropods of different functional groups on 16 permanent plots following two windstorms (Vivian and Lothar) in coniferous and broadleaf forests at different elevations in Central Europe over two decades. Flight interception and pitfall traps were operated during the entire growing seasons in three habitat types per site: unsalvaged windthrow, salvaged windthrow and control forest. In total, 524,115 individuals from 1666 arthropod species were identified, of which more than 90% occurred in windthrows, including 40%–53% species exclusively found in windthros. Over the two decades, saproxylics, herbivores, pollinators, predators and endangered species showed significantly higher species numbers and abundances in windthrows than in control forests, where only 6% exclusive species occurred. Arthropod communities in windthrows showed distinct dynamics during the two decades. Their species numbers and abundances peaked in the first 3 years, coined by saproxylic species, such as bark beetles, and by pollinating hoverflies. While abundances declined rapidly, species numbers remained elevated for two decades. Arthropod similarity between windthrows and forests (indicating resilience) increased with time but depended on elevation and forest type. After 20 years, it reached an average of 50% in lowland broadleaf forests, but only 30% in high‐elevation spruce forests, indicating lower resilience. Salvage logging had no significant effect on overall species numbers but altered species composition. More than 10% exclusive species were found in salvaged and up to 20% in unsalvaged windthrows, with the latter supporting more endangered species, particularly towards the second decade. Synthesis and applications. Our study shows that windthrow causes an initial boost of arthropod diversity. While abundances thereafter rapidly decline, species numbers remain at relatively high levels during at least two decades. Unsalvaged windthrows are an indispensable resource for endangered species, particularly in later wood decay stages.

Demographic rates and diversity vary with tree stature and ontogenetic stage in an African tropical rainforest

AbstractThe vertical gradient of light in closed‐canopy forests selects for trees with different adult statures, but our understanding of how stature affects forest diversity and demography is unclear. In a species‐rich rainforest in Cameroon, we quantified the contributions of four growth forms of increasing adult stature (treelet, understory, canopy, emergent species) to forest structure and diversity, and investigated variation in life history trade‐offs across growth forms. Treelets had the highest stem density, contributed the most to forest diversity, and diverged from larger statured species in terms of demographic trade‐offs. Growth rates were slower for smaller statured than for larger statured species, and at the adult stage, treelets had significantly lower mortality than other growth forms. We observed significant interspecific trade‐off relationships between staure and demographic rates that often differed between growth forms. Recruitment rate strongly declined with adult stature for all growth forms, but recruitment per reproductive adult declined only for emergents. While we observed a significant growth‐mortality trade‐off across all species, the trade‐off was similar across growth forms. Smaller statured species in our study are not light‐demanding but rather treelet and understory species that live entirely in the shaded understory. Differences in how historical biogeography has shaped species pools may ultimately cause variation in how adult stature contributes to tropical forest diversity.

Impact of Flooding Frequency on the Diversity and Structures of Riparian Forests in Southwestern, Nigeria

Impact of Flooding Frequency on the Diversity and Structures of Riparian Forests in Southwestern, Nigeria

Comparative Analyses and Phylogenetic Dependence in Traits and Trends of the Dipterocarpaceae.

The role of trait evolution in shaping the functional and ecological diversity of tropical forests remains poorly understood. Analyses of trait variation as a function of evolutionary history and environmental variables should reveal the drivers of species distributions, as well as generate insights valuable to conservation. Here, we focus on the Dipterocarpaceae, the key plant family underpinning the hyperdiversity of South-East Asian tropical forest canopies and of major conservation concern due to over-exploitation for timber, cultivation, and climate change. Our objectives are to (i) assess whether dipterocarp species traits are phylogenetically conserved through a phylogenetic signal, indicating phylogenetic niche conservatism (PNC); (ii) determine the drivers of dipterocarp species distribution; (iii) examine the relationship between morphological traits with habitat factors; and (iv) assess the correlation between conservation status and phylogeny. We compiled a dataset of species-level plant traits of the Dipterocarpaceae together with population-level ecological trends. We found substantial evidence of phylogenetic conservatism of plant traits in dipterocarp species, with a moderate to strong phylogenetic signal, and that the elevational gradient shapes dipterocarp species distribution pan-tropically. Morphological traits including height and diameter show phylogenetically dependent relationships with soil type, while shade tolerance traits are related to survival. We find that conservation status is related to phylogeny and correlated with population trend status, suggesting that decreasing population trends correlated with conservation status. Overall, our analyses show that functional traits and ecological trends of dipterocarp species are shaped by the phylogenetic history. Our study highlights that conservation strategies require consideration of the consequences of these relationships for long-term population changes.

Assessing Wildfire Susceptibility and Spatial Patterns in Diverse Forest Ecosystems Across China: An Integrated Geospatial Analysis

Assessing Wildfire Susceptibility and Spatial Patterns in Diverse Forest Ecosystems Across China: An Integrated Geospatial Analysis

KEANEKARAGAMAN VEGETASI HUTAN MANGROVE DI KECAMATAN KURAU KABUPATEN TANAH LAUT

Kurau sub-district in Tanah Laut Regency is known to have a fairly extensive mangrove forest with great potential. One of the potentials is the variety of mangrove vegetation that grows in the forest. vegetation that grows in it. Knowing the diversity of mangrove forest species in Kurau sub-district aims to provide a scientific basis for in Kurau sub-district aims to provide a scientific basis for protecting and monitoring the forest. and forest supervision. The method used in the research is the technique of collecting data with purposive sampling and then analyzing with calculation of importance value index and Shannon-Wiener diversity index. Research The research was conducted based on the level of forest density consisting of high, medium and sparse forest density. high, medium, and sparse. The results obtained there are 11 types of vegetation that grow in mangrove forests and are dominated by the type of mangrove (Rhizophora mangle) which grows from seedling to tree level. Then followed by Rambai (Sonneratia caseolaris) and Api-api (Avicennia lanata). The level of species diversity in this mangrove forest is categorized as high with an index value of 5.5. high category with an index value of 5.46 for high forest density, 4.22 for medium forest density. While for sparse forest density included in the medium diversity category with a value of 2.34.

Composition and Diversity of Understory and Canopy Species Vary Along a Logging Gradient in an African Semi-Deciduous Tropical Rainforest

The effect of timber cutting and related management on species composition and diversity in tropical forests has been reported in earlier studies, but the potentially different effects on understory and canopy tree species remains unclear. Our study aim was to assess the variation in species composition and diversity of understory and canopy species along a timber removal (“logging”) gradient. We assessed the species composition, alpha and beta diversity, and compared species composition of canopy trees in plots with different management histories in Budongo. Our findings revealed logging contributed 18.1% to the beta diversity of species composition as measured by distance-based redundancy analysis (dbRDA) and species composition decreased with logging intensity (R2 = −0.415). Unlogged forest had higher species diversity for both understory and canopy tree species compared with logged forests. Species composition of logged/unlogged forests were significantly different from those of the forest succession types. Our study adds new information on the effect of logging on the species composition of understory and canopy trees in lowland tropical forests. We found logged forests do not recover species composition within seven decades, diversity within, and what previously distinct successional types were, have become, and remain, mixed in nature.

Landscape influences bat suppression of pine processionary moth: Implications for pest management.

Bats provide important ecosystem services, particularly in agriculture, yet integrating bat management into conservation plans remains challenging. Some landscape features considerably influence bat presence, diversity, and ecosystem service provision. Understanding the relationship between landscape structure, composition, pest suppression, and ecosystem services is crucial. We modelled areas where bats most effectively suppress pine processionary moths (Thaumetopoea pityocampa), considering landscape characteristics to predict ecosystem services and optimise pest suppression in Serra da Estrela, Portugal. Faecal samples collected during fieldwork were analysed for pine processionary moth presence in bat diets. Lasso regression assessed spatial landscape variables to create an "optimal landscape" for predation. Landscape structure and composition influenced pest suppression differently, with the greatest impact within a 5000-m buffer. "Riparian edge" and "tree cover density" were key habitat structure variables supporting bat navigation and access to hunting areas, while "other forest" and "vineyard/orchard" areas were important composition variables. Optimising landscape composition involves incorporating diverse forest within agroforestry systems to enhance pest suppression by creating habitats reflecting bats' foraging preferences. We recommend strategies focusing on riparian edge conservation, selective canopy reduction, and promoting diverse forest compositions. These strategies aim to create mosaic landscapes balancing land uses, fostering optimal conditions for bat foraging. Our study shows edges provide the highest rates of bats-pine processionary moth interactions. However, caution is needed to avoid excessive fragmentation, which may reduce habitat suitability and increase pest presence before effective bat predation. A balanced approach, focusing on edge creation without over-fragmenting the landscape, is key to promoting sustainable pest management.

Deadwood Diversity of Boreal and Sub-boreal Old-growth Forests in Southern Finland

In the last century, old-growth forests in boreal and sub-boreal zone have decreased, along with their contribution to biological diversity. In order to carry on management strategies aimed at maintaining deadwood diversity in old-growth forests, it is fundamental to identify simply and readily measurable indicators. This study investigated the deadwood diversity in four old-growth forests in southern Finland. Five indicators of deadwood diversity (deadwood amount and diversity by species, component, decay class, water reservoir in logs) were estimated and analysed. The results showed an average deadwood volume of approximately 85±28 m3·ha−1 diversified by decay class and component. Besides, the results showed average Shannon index values four the four old-growth forests equal to 0.488 for deadwood species diversity, 0.932 for component diversity, and 1.286 for decay class diversity. The set of deadwood diversity indicators used in this study successfully supported the analysis of deadwood diversity in boreal and sub-boreal old-growth forests.

Effects of Pittosporum undulatum Vent. invasion on forest diversity and structure in Southern Brazil

ABSTRACT Invasive alien species are considered the second largest cause of biodiversity loss in the world. Pittosporum undulatum Vent., is a native species to Australia and was introduced to Brazil, currently being considered invasive in several regions. Here we analysed the floral and structural composition of forest fragments with varying degress of biological invasion by P. undulatum and assess the relationship between its presence and community diversity. A phytosociological survey was conducted in disturbed and reference forests within two forest fragments in Southern Brazil, assessing tree species diversity, structural and environmental variables between communities across all ontogenetic stages. We recorded 7554 individuals from 35 botanical families and 87 species at all ontogenetic stages, including adults, saplings, and seedlings. P. undulatum showed the highest importance in the adult and sapling stages. The presence of P. undulatum in the forest community is not affecting the richness and diversity of the fragments when the communities were analysed separately (as disturbed and reference forests), but we may see their effect when all forests were analysed together in different ontogenetic stages. In addition, there was a reduction in basal area with advancing successional stages, contrary to typical patterns found in mature forests. The presence of P. undulatum in the reference forest suggests that this species is invading older, more established forests.

МОНИТОРИНГ БИОРАЗНООБРАЗИЯ ЕЛЬНИКОВ ЕВРОПЕЙСКОЙ ЧАСТИ РОССИИ ПОСЛЕ ПРИРОДНЫХ И АНТРОПОГЕННЫХ «КАТАСТРОФ»

We analyzed the main trends of the change in the species richness of plant communities after catastrophic natural (catastrophicwindthrow, fires, large bark beetle outbreaks) and anthropogenic (clear felling) disturbances. The main factor determining the increase in species richness was the intensity of ecosystem disturbance after ca- tastrophes. The greatest disturbance was caused by clear-cut logging, when all timber was removed from the felling area by tractors. Fires also could totally destroy stands and all components of the forest ecosystem. Large- scale wind damage affected only the trees of the upper layer, while all other components of the plant communities were slightly damaged. The bark beetle outbreaks cause the death only of upper layer spruce trees, while the whole forest ecosystem remains unchanged. The degree of disturbance of stands, undergrowth, herb-dwarf scrubs layer, moss cover, litter and soil during the dieback of spruce forests as a result of ‘catastrophes’ determines the degree of vegetation recovery in disturbed areas. We studied the spruce forest in the zone of coniferous-broadleaved forests of the Moscow region, affected by an outbreak of typograph bark beetle.Dynamics of understory plant species richness was fundamentally different after stand salvage logging following beetle outbreaks and in unlogged standswith preserved deadwood. Monitor- ing observations of plant communities during 10 years on permanent sample plots revealed the main feature of the plant species succession after clear felling. For the first six years succession passed through the herb and the shrub stages with a sharp increase in species and structural diversity of plant communities. Only in the forest stage the species composition characteristic of the forest was restored. In the deadwood stand the forest communities was preserved and no differences in the dynamics of species richness of the original undisturbed forest were detected. Only dominance of species in the stand and herb-shrub layer changed. If man don't clear cut dead and wind- damaged areas of spruce forests, it will result in development of mixed forests with increased resistance to pests and forest diseases. Monocultures of spruce forests may be replaced by mixed forests, increasing the diversity of forests.

Monitoring Postfire Biodiversity Dynamics in Mediterranean Pine Forests Using Acoustic Indices

In recent decades, climate change has significantly influenced the frequency and intensity of wildfires across Mediterranean pine forests. The loss of forest cover can bring long-term ecological changes that impact the overall biodiversity and alter species composition. Understanding the long-term impact of wildfires requires effective and cost-efficient methods for monitoring the postfire ecosystem dynamics. Passive acoustic monitoring (PAM) has been increasingly used to monitor the biodiversity of vocal species at large spatial and temporal scales. Using acoustic indices, where the biodiversity of an area is inferred from the overall structure of the soundscape, rather than the more labor-intensive identification of individual species, has yielded mixed results, emphasizing the importance of testing their efficacy at the regional level. In this study, we examined whether widely used acoustic indicators were effective at capturing changes in the avifauna diversity in Pinus halepensis forest stands with different fire burning histories (burnt in 2001, 2009, and 2018 and unburnt for >20 years) on the Sithonia Peninsula, Greece. We recorded the soundscape of each stand using two–three sensors across 11 days of each season from March 2022 to January 2023. We calculated for each site and season the following five acoustic indices: the Acoustic Complexity Index (ACI), Acoustic Diversity Index (ADI), Acoustic Evenness Index (AEI), Normalized Difference Soundscape Index (NDSI), and Bioacoustic Index (BI). Each acoustic index was then assessed in terms of its efficacy at predicting the local avifauna diversity, as estimated via two proxies—the species richness (SR) and the Shannon Diversity Index (SDI) of vocal bird calls. Both the SR and SDI were calculated by having an expert review the species identification of calls detected within the same acoustic dataset by the BirdNET convolutional neural network algorithm. A total of 53 bird species were identified. Our analysis shows that the BI and NDSI have the highest potential for monitoring the postfire biodiversity dynamics in Mediterranean pine forests. We propose the development of regional-scale acoustic observatories at pine and other fire-prone Mediterranean habitats, which will further improve our understanding of how to make the best use of acoustic indices as a tool for rapid biodiversity assessments.

Inventory List of Plant Diversity in Tropical Dry Deciduous Forest of Pench Tiger Reserve, Maharashtra, India

Aim: To assess the phyto diversity of pench tiger reserve, Maharashtra, India. Place and Duration of Study: Pench Tiger Reserve (PTR), June 2022 to December 2023. Methodology: The study was carried out by laying out quadratic sample plots in the PTR given by National Forest Inventory working plan code-2014 The plot size was 0.1 ha with 31.62 m x 31.62 m quadrats. Results: The study reveals a rich biodiversity comprising 863 species across 554 genera and 117 families, along with 8 varieties and 2 sub-species. The predominant taxa are herbs, accounting for 34.06% of species, followed by trees at 23.29%, climbers at 15.17%, grasses at 13.09%, sedges at 7.3%, epiphytic herbs at 0.8%, and bamboo at 0.2%. Fabaceae emerges as the most species-rich family in comparable studies, underscoring its ecological significance. Conclusion: The study emphasizes the importance of comprehensive biodiversity inventories for understanding and conserving tropical forest ecosystems. This research provides valuable baseline data essential for future ecological studies, environmental assessments, and effective.

Mapping elevational patterns of functional diversity of canopy species in an alpine forest using drone multispectral and LiDAR data

Understanding the patterns and drivers of plant functional diversity is crucial for assessing the functioning and resilience of terrestrial ecosystems to global climate change. Despite the well-documented variability in plant species richness with elevation, the elevational patterns and underlying mechanisms of functional diversity remain poorly understood. This study employed drone equipped with multispectral and light detection and ranging (LiDAR) sensors to investigate the elevational gradients (3208 m to 3984 m) of physiological and morphological functional diversity of canopy tree species in six 1-hectare plots in Baima Snow Mountain, Yunnan, China. Results demonstrated that drone-based multispectral and LiDAR data enabled high-resolution mapping of physiological and morphological functional diversity in forest canopies over large areas. Importantly, functional diversity declined with increasing elevation, with a more pronounced pattern observed for physiological traits compared to morphological traits. Variance partitioning analysis revealed that functional richness was primarily driven by climatic and edaphic factors, particularly temperature, while plant factors played a subordinate role, interacting with climate and soil. Our findings highlight the potential of drone for rapid, large-scale monitoring and mapping of canopy species functional diversity in forests. Moreover, the influence of climate and soil factors on functional diversity suggests that future global warming may enhance functional diversity in alpine forest ecosystems, with implications for ecosystem functioning and services.

Integrating conspecifics negative density dependence, successional and evolutionary dynamics: Towards a theory of forest diversity

Tree successional diversity is evident even to casual observers and has a well-understood physiological basis. Various life history trade-offs, driven by interspecific variation in a single trait, help maintain this diversity. Conspecific negative density dependence (CNDD) is also well-documented and reduces tree vital rates independently of succession strategies. The CNDD hypothesis is frequently justified by specialist natural enemies at a separate trophic level. We integrate these processes into an analytical demographic model, spanning short-term plant physiological responses to the dynamics of a large forest mosaic connected to a metacommunity. Surprisingly, multiple trade-offs do not necessarily increase diversity, as suboptimal trait combinations lead to strategies that cannot compete for successional niches, explaining the weak correlation between functional traits and succession position. Succession alone can sustain half of the species in the metacommunity, with diversity increasing linearly with CNDD strength. The steeper increase with larger metacommunities suggests CNDD plays a greater role in tropical forests. However, if each successional type contains multiple equivalent species, CNDD maintains diversity but becomes less effective in promoting successional diversity, consistent with some tropical forests being less successional diverse. Additionally, CNDD enhances the likelihood of successful speciation and shifts life-history trait frequency by affecting more late-successional species.

Long-term stability of productivity increases with tree diversity in Canadian forests

The temporal stability of forest productivity is a key ecosystem function and an essential service to humanity. Plot-scale tree diversity experiments with observations over 10 to 11 y indicate that tree diversity increases stability under various environmental changes. However, it remains unknown whether these small-scale experimental findings are relevant to the longer-term stability of natural forests. Using 7,500 natural forest plots across much of Canada, monitored over three to four decades on average, we provide strong evidence that higher temporal stability (defined as the mean productivity divided by its SD over time) is consistently associated with greater tree functional, phylogenetic, and taxonomic diversity across all lengths of observations. Specifically, increasing functional diversity from its minimum to maximum values increases stability, mean productivity, and the temporal SD of productivity by 14%, 36%, and 28%, respectively. Our results highlight that the promotion of functionally, phylogenetically, and/or taxonomically diverse forests could enhance the long-term productivity and stability of natural forests.