Natural spruce forests are restricted to the highest mountain ranges in the Czech Republic. Spruce is also the commonest tree species in managed forests. Owing to a massive decline of spruce forests ...in Central Europe, caused by recent climatic fluctuations and disturbances, the lichen diversity and species composition was compared between ten representative natural mountain old-growth forests in the Czech Republic and their counterparts in mature managed forests. The old-growth forests are characterized by a higher species richness, abundance, number of Red-listed species, functional, taxonomic and phylogenetic diversities. Plots with the highest species richness are situated in the Šumava Mountains, an area with a relatively low sulphur deposition in the past. Bioindication analysis searching for lichen indicators supported several species (e.g.
Xylographa vitiligo
,
Chaenotheca sphaerocephala
) and genera (e.g.
Calicium
,
Xylographa
) with a strong preference for old-growth forests. Analysis of lichen functional traits revealed a higher abundance of species with a vegetative reproduction in managed forests that may be explained by a higher efficiency in colonization by young successional stages. Lichens with stalked apothecia, pigmented ascospores and large ascospores are more frequent in old-growth forests. Our results are briefly discussed in terms of nature conservation, focusing on national refugees of old-growth forest species, biodiversity hot-spots, practical use of indicator species and representative measures for an evaluation of forest quality.
Various ecological mechanisms influence the forms of species richness relationships (SRRs). These mechanisms can be gathered under five general categories: more individuals, environmental ...heterogeneity, dispersal limitations, biotic interactions, and multiple species pools. Often only the first two categories are discussed. In contrast, we examine all five and explore how they can influence the form of SRRs. We discuss how various sampling schemes and methods of SRR construction can be used to gain insight about how various processes influence species richness patterns. The field is ripe for probing these effects through more complex simulation models or more sophisticated mathematical approaches. To facilitate deeper understanding, we need to embrace the full spectrum of SRRs and reconsider the assumed common knowledge about the functional form of SRRs.
The relationship between species richness and the space or time over which it is sampled has received increasing attention over the past decade, resulting in extensive debates about terminology and methods of construction. These debates reflect deep conceptual issues; to resolve them we discuss the long history of species richness relationships (SRRs) and the connections among different methodological and terminological approaches. We reinforce recent calls to organize the variety of methods used to construct SRRs into a cohesive structure. SRRs are descriptors of various aspects of inventory (αα- and γγ-) diversity and the various types of SRRs serve different purposes. Contrary to most claims, SRRs do not provide a direct measure of differentiation (ββ-) diversity.
Although it is generally recognized that global biodiversity is declining, few studies have examined long‐term changes in multiple biodiversity dimensions simultaneously. In this study, we quantified ...and compared temporal changes in the abundance, taxonomic diversity, functional diversity, and phylogenetic diversity of bird assemblages, using roadside monitoring data of the North American Breeding Bird Survey from 1971 to 2010. We calculated 12 abundance and diversity metrics based on 5‐year average abundances of 519 species for each of 768 monitoring routes. We did this for all bird species together as well as for four subgroups based on breeding habitat affinity (grassland, woodland, wetland, and shrubland breeders). The majority of the biodiversity metrics increased or remained constant over the study period, whereas the overall abundance of birds showed a pronounced decrease, primarily driven by declines of the most abundant species. These results highlight how stable or even increasing metrics of taxonomic, functional, or phylogenetic diversity may occur in parallel with substantial losses of individuals. We further found that patterns of change differed among the species subgroups, with both abundance and diversity increasing for woodland birds and decreasing for grassland breeders. The contrasting changes between abundance and diversity and among the breeding habitat groups underscore the relevance of a multifaceted approach to measuring biodiversity change. Our findings further stress the importance of monitoring the overall abundance of individuals in addition to metrics of taxonomic, functional, or phylogenetic diversity, thus confirming the importance of population abundance as an essential biodiversity variable.
Plants are known to influence belowground microbial community structure along their roots, but the impacts of plant species richness and plant functional group (FG) identity on microbial communities ...in the bulk soil are still not well understood. Here, we used 454‐pyrosequencing to analyse the soil microbial community composition in a long‐term biodiversity experiment at Jena, Germany. We examined responses of bacteria, fungi, archaea, and protists to plant species richness (communities varying from 1 to 60 sown species) and plant FG identity (grasses, legumes, small herbs, tall herbs) in bulk soil. We hypothesized that plant species richness and FG identity would alter microbial community composition and have a positive impact on microbial species richness. Plant species richness had a marginal positive effect on the richness of fungi, but we observed no such effect on bacteria, archaea and protists. Plant species richness also did not have a large impact on microbial community composition. Rather, abiotic soil properties partially explained the community composition of bacteria, fungi, arbuscular mycorrhizal fungi (AMF), archaea and protists. Plant FG richness did not impact microbial community composition; however, plant FG identity was more effective. Bacterial richness was highest in legume plots and lowest in small herb plots, and AMF and archaeal community composition in legume plant communities was distinct from that in communities composed of other plant FGs. We conclude that soil microbial community composition in bulk soil is influenced more by changes in plant FG composition and abiotic soil properties, than by changes in plant species richness per se.
1. Given the substantial contributions of forest biodiversity and ecosystem services to society, forest sciences have a large potential to contribute to the integrity and sustainability of our ...future. This is especially true when the roles of biodiversity for sustaining ecosystem services are considered. 2. The rapid expansion of sustainable forest management (SFM) has resulted in the adoption of various forest management frameworks intended to safeguard biodiversity. Concurrently, the importance of forest ecosystem services has been increasingly recognized. Although some initiatives aimed at conserving both biodiversity and ecosystem services are emerging, knowledge gaps still exist about their relationships and potential trade-offs in forests. Given recent advancements, increasing opportunities and some lags in forest ecology, further research on biodiversity, ecosystem functions and services will play substantial roles in the development of SFM practices. 3. Here, we identified key issues including (i) relationships between biodiversity and ecosystem function as a foundation of ecological integrity, (ii) resilience thinking to better prepare for and adapt to environmental changes, (iii) social-ecological perspectives that facilitate realworld conservation and management and (iv) theory-driven restoration that bridges science and practice. Thus, we illustrate priorities and future possibilities in applied ecology studies in forests, which will help society and ecosystems to build capacity and resilience to face uncertainty in the changing environment. 4. Synthesis and applications. Under substantial human influences, forests are highly likely to be largely altered, potentially leading to the emergence of novel ecosystems or alternative stable states. Management thus needs more flexible, novel measures to address the significant uncertainty this generates. Resilience-based approaches are important to respond adaptively to future changes and cope with surprises, potentially providing multiple options. Although challenges exist, theory should play an important role in managing, conserving and restoring forest ecosystems. The issues discussed here should receive further attention in the context of the multiple goals of sustainable forest management.
Aim
Ancient tropical mountains are megadiverse, yet little is known about the distribution of their species. We aimed to disentangle the effects of latitudinal and elevational gradients on the ...distribution of species of Aculeata and to understand the effects of climatic variables across different spatial scales of diversity (α‐, γ‐, and β‐diversity).
Location
Campo rupestre in the Espinhaço Mountain Range, Southeast Brazil.
Taxon
Bees, wasps, and ants (Aculeata: Hymenoptera).
Methods
We used a unique dataset built from sampling species of Aculeata at 24 study sites across 12 mountains, covering 1200 km from south to north and an elevational range of 1000 to 2000 m. We explored the elevational and latitudinal patterns of α‐ (site), γ‐ (mountain), and β‐diversity among samples at each location (βLocal). We also tested the effect of elevational range on β‐diversity in each mountain (βMountain) and, on a larger scale (βRegional), if β‐diversity is influenced by geographical and environmental distances. Finally, we tested whether climatic variables underpin the observed patterns.
Results
Latitude had no effect on diversity. We found a decrease in both site and mountain diversity and, only for bees, βLocal increased with elevation. Climatic variables (temperature, wind, and precipitation) and their interactions were important drivers of diversity, with temperature being the most important. Finally, βMountain increased with mountain elevation range, and βRegional increased with the geographical and environmental distances.
Main conclusions
Our results showed that variation in species richness and composition across mountains is strongly associated with elevational gradient, which showed stronger climatic variation than latitudinal gradient. Therefore, despite having narrow elevational ranges, the biogeographical effects of tropical mountains drive high diversity. Facing global climate changes, this limited elevational gradient may limit species range shifts, leading to severe biodiversity losses.
There is increasing evidence that mixed‐species forests can provide multiple ecosystem services at a higher level than their monospecific counterparts. However, most studies concerning tree diversity ...and ecosystem functioning relationships use data from forest inventories (under noncontrolled conditions) or from very young plantation experiments. Here, we investigated temporal dynamics of diversity–productivity relationships and diversity–stability relationships in the oldest tropical tree diversity experiment. Sardinilla was established in Panama in 2001, with 22 plots that form a gradient in native tree species richness of one‐, two‐, three‐ and five‐species communities. Using annual data describing tree diameters and heights, we calculated basal area increment as the proxy of tree productivity. We combined tree neighbourhood‐ and community‐level analyses and tested the effects of both species diversity and structural diversity on productivity and its temporal stability. General patterns were consistent across both scales indicating that tree–tree interactions in neighbourhoods drive observed diversity effects. From 2006 to 2016, mean overyielding (higher productivity in mixtures than in monocultures) was 25%–30% in two‐ and three‐species mixtures and 50% in five‐species stands. Tree neighbourhood diversity enhanced community productivity but the effect of species diversity was stronger and increased over time, whereas the effect of structural diversity declined. Temporal stability of community productivity increased with species diversity via two principle mechanisms: asynchronous responses of species to environmental variability and overyielding. Overyielding in mixtures was highest during a strong El Niño‐related drought. Overall, positive diversity–productivity and diversity–stability relationships predominated, with the highest productivity and stability at the highest levels of diversity. These results provide new insights into mixing effects in diverse, tropical plantations and highlight the importance of analyses of temporal dynamics for our understanding of the complex relationships between diversity, productivity and stability. Under climate change, mixed‐species forests may provide both high levels and high stability of production.
Millions of hectares of degraded land in the tropics and subtropics are targeted for restoration with tree plantations. To assess whether this might be best achieved with mixed‐species plantations, we analysed the effects of species diversity and structural diversity on productivity and its temporal stability in the oldest tropical tree diversity experiment. At the tree neighbourhood‐ and community‐level, diversity enhanced productivity and its stability in mixed compared to monospecific stands. Beneficial diversity effects increased with stand development and were highest at the highest levels of diversity and strongest under drought conditions.
Biodiversity is essential to healthy ecosystem function, influencing productivity and resilience to disturbance. Biodiversity loss endangers essential ecosystem services and risks unacceptable ...environmental consequences. Global biodiversity observations are needed to provide a better understanding of the distribution of biodiversity, to better identify high priority areas for conservation and to help maintain essential ecosystem goods and services. Traditional in situ biodiversity monitoring is limited in time and space and is usually a costly and time-consuming enterprise. Remote sensing can provide data over a large area in a consistent, objective manner and has been used to detect plant biodiversity in a range of ecosystems, typically based on relating spectral properties to the distribution of habitat, species or functional groups. Recent years have witnessed the emergence of methods using imaging spectroscopy to assess biodiversity via plant traits or spectral information content. However, questions regarding the complex drivers of plant optical properties and the scale dependence of spectral diversity – biodiversity relationship confound diversity monitoring using remote sensing and must first be better understood before these methods can be operationally applied. To address some of these topics, we (1) review the history of remote sensing approaches in biodiversity estimation, summarizing the pros and cons of different methods, (2) illustrate successes and major gaps of remote sensing of biodiversity, and (3) identify promising future directions. We focus on emerging methods using spectral diversity (optical diversity) as a proxy for terrestrial plant diversity that offer to revolutionize the study of diversity in its different dimensions (phylogenetic, taxonomic, and functional diversity) from remote sensing. We also discuss remaining knowledge gaps and ways spectral diversity might be effectively integrated into a global biodiversity monitoring system, bridging a gap between ecology and remote sensing.
•We review the history of remote sensing approaches for biodiversity estimation.•We summarize the pros and cons of different methods in remote sensing of plant biodiversity.•A particular focus relates spectral diversity to biodiversity at different scales.•Major gaps are discussed in the context of a global biodiversity monitoring system.
1. Ecological studies identifying a positive relationship between biodiversity and ecosystem services motivate projections that higher plant diversity will increase services from agroecosystems. ...While this idea is compelling, evidence of generalizable relationships between biodiversity and ecosystem services that could be broadly applied in agricultural systems is lacking. 2. Cover crops grown in rotation with cash crops are a realistic strategy to increase agroecosystem diversity. We evaluated the prediction that further increasing diversity with cover crop polycultures would enhance ecosystem services and multifunctionality in a 2-year study of eighteen cover crop treatments ranging in diversity from one to eight species. Five ecosystem services were measured in each cover crop system and regression analysis used to explore the relationship between multifunctionality and several diversity indices. 3. As expected, there was a positive relationship between species richness and multifunctionality, but it only explained a small fraction of variance in ecosystem services (marginal R² = 0-05). In contrast, indices of functional diversity, particularly the distribution of trait abundances, were stronger predictors of multifunctionality (marginal R² = 0-15-0-38). 4. Synthesis and application. In a corn production system, simply increasing cover crop species richness will have a small impact on agroecosystem services, but designing polycultures that maximize functional diversity may lead to agroecosystems with greater multifunctionality.
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