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.
The award-winning Managing Diversity uses an interdisciplinary approach to provide students with an understanding of diversity from a global perspective.
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.
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.
The Ethnically Diverse Workplace: Experience of Immigrant Indian Professionals in Australiadocuments the perceptions and experiences of exclusion after inclusion by Indian immigrants, working to ...encourage and promote greater understanding so that immigrant Indian professionals maybe better understood and served in Australia.
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.
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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