Environmental drivers of ant species richness and composition across the Argentine Pampas grassland

2018 ◽  
Vol 43 (4) ◽  
pp. 424-434 ◽  
Author(s):  
Carolina S. Ramos ◽  
M. Isabel Bellocq ◽  
Carolina I. Paris ◽  
Julieta Filloy
2020 ◽  
Vol 29 (13) ◽  
pp. 3533-3550
Author(s):  
Gabriele Gheza ◽  
Silvia Assini ◽  
Chiara Lelli ◽  
Lorenzo Marini ◽  
Helmut Mayrhofer ◽  
...  

Abstract In dry habitats of European lowlands terricolous lichens and bryophytes are almost neglected in conservation practises, even if they may strongly contribute to biodiversity. This study aims at (a) testing the role of heathlands, acidic and calcareous dry grasslands for lichen and bryophyte diversity and conservation in lowland areas of northern Italy characterized by high human impact and habitat fragmentation; (b) detecting the effect of environmental drivers and vegetation dynamics on species richness and composition. Lichens, bryophytes, vascular plants, and environmental variables were recorded in 287 circular plots for 75 sites. Our results indicate that heathlands, acidic and calcareous dry grasslands host peculiar terricolous lichen and bryophyte communities that include several species of conservation concern. Thus, each habitat provides a complementary contribution to lichen and bryophyte diversity in continental lowland landscapes. Furthermore, in each habitat different factors drive species richness and composition with contrasting patterns between lichens and bryophytes. In terms of conservation, our results indicate that management of lowland dry habitats should act at both local and landscape scales. At local scale, vegetation dynamics should be controlled in order to avoid biodiversity loss due to vegetation dynamics and wood encroachment. At the landscape scale, patches of all the three habitats should be maintained to maximize regional diversity.


Diversity ◽  
2020 ◽  
Vol 12 (5) ◽  
pp. 188 ◽  
Author(s):  
Sina M. Weier ◽  
Mark Keith ◽  
Götz G. Neef ◽  
Daniel M. Parker ◽  
Peter J. Taylor

The Okavango River Basin is a hotspot of bat diversity that requires urgent and adequate protection. To advise future conservation strategies, we investigated the relative importance of a range of potential environmental drivers of bat species richness and functional community composition in the Okavango River Basin. During annual canoe transects along the major rivers, originating in the central Angolan highlands, we recorded more than 25,000 bat echolocation calls from 2015 to 2018. We corrected for possible biases in sampling design and effort. Firstly, we conducted rarefaction analyses of each survey year and sampling appeared to be complete, apart from 2016. Secondly, we used total activity as a measure of sample effort in mixed models of species richness. Species richness was highest in the Angola Miombo Woodlands and at lower elevations, with higher minimum temperatures. In total, we identified 31 individual bat species. We show that even when acoustic surveys are conducted in remote areas and over multiple years, it is possible to correct for biases and obtain representative richness estimates. Changes in habitat heterogeneity will have detrimental effects on the high richness reported here and human land-use change, specifically agriculture, must be mediated in a system such as the Angolan Miombo Woodland.


Water ◽  
2020 ◽  
Vol 12 (7) ◽  
pp. 1984
Author(s):  
Anthi Oikonomou ◽  
Konstantinos Stefanidis

Disentangling the main drivers of species richness and community composition is a central theme in ecology. Freshwater biodiversity patterns have been poorly explored; yet, it has been shown that different freshwater biota have different, often contrasting responses to environmental gradients. In this study, we investigated the relative contribution of geographical and environmental (habitat-, climate- and water quality-related) factors/gradients in shaping the α- and β-diversity patterns of macrophytes and fish in sixteen natural freshwater lakes of an unexplored Balkan biodiversity hotspot, the Southern Balkan Peninsula. We employed generalized linear modeling to identify drivers of α-diversity, and generalized dissimilarity modeling to explore commonalities and dissimilarities of among-biota β-diversity. Species richness of both biota was significantly associated with lake surface area, whereas macrophytes had an inverse response to altitude, compared to fish. Both species turnover and nestedness significantly contributed to the total β-diversity of macrophytes. In contrast, species turnover was the most significant contributor to the total fish β-diversity. We found that the compositional variation of macrophytes is primarily limited by dispersal and ultimately shaped by environmental drivers, resulting in spatially structured assemblages. Fish communities were primarily shaped by altitude, highlighting the role of species sorting. We conclude that among-biota diversity patterns are shaped by different/contrasting factors, and, thus, effective/sustainable conservation strategies should encompass multiple aquatic biota.


2020 ◽  
Vol 117 (39) ◽  
pp. 24345-24351 ◽  
Author(s):  
Enrique Valencia ◽  
Francesco de Bello ◽  
Thomas Galland ◽  
Peter B. Adler ◽  
Jan Lepš ◽  
...  

The stability of ecological communities is critical for the stable provisioning of ecosystem services, such as food and forage production, carbon sequestration, and soil fertility. Greater biodiversity is expected to enhance stability across years by decreasing synchrony among species, but the drivers of stability in nature remain poorly resolved. Our analysis of time series from 79 datasets across the world showed that stability was associated more strongly with the degree of synchrony among dominant species than with species richness. The relatively weak influence of species richness is consistent with theory predicting that the effect of richness on stability weakens when synchrony is higher than expected under random fluctuations, which was the case in most communities. Land management, nutrient addition, and climate change treatments had relatively weak and varying effects on stability, modifying how species richness, synchrony, and stability interact. Our results demonstrate the prevalence of biotic drivers on ecosystem stability, with the potential for environmental drivers to alter the intricate relationship among richness, synchrony, and stability.


2016 ◽  
Vol 19 (9) ◽  
pp. 1009-1022 ◽  
Author(s):  
Robert K. Colwell ◽  
Nicholas J. Gotelli ◽  
Louise A. Ashton ◽  
Jan Beck ◽  
Gunnar Brehm ◽  
...  

2018 ◽  
Vol 117 (11) ◽  
pp. 3591-3599 ◽  
Author(s):  
L. Ancillotto ◽  
V. Studer ◽  
T. Howard ◽  
V. S. Smith ◽  
E. McAlister ◽  
...  

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Pamela E. Pairo ◽  
Estela E. Rodriguez ◽  
M. Isabel Bellocq ◽  
Pablo G. Aceñolaza

AbstractTree plantations have become one of the fastest-growing land uses and their impact on biodiversity was evaluated mainly at the taxonomic level. The aim of this study was to analyze environmental changes after the Eucalyptus plantation in an area originally covered by natural grasslands, taking into account the alpha and beta (taxonomic and functional) diversity of plant communities. We selected nine plantation ages, along a 12 years chronosequence, with three replicates per age and three protected grasslands as the original situation. At each replicate, we established three plots to measure plant species cover, diversity and environmental variables. Results showed that species richness, and all diversity indices, significantly declined with increasing plantation age. Canopy cover, soil pH, and leaf litter were the environmental drivers that drove the decrease in taxonomic and functional diversity of plants through the forest chronosequence. Based on the path analyses results, canopy cover had an indirect effect on plant functional diversity, mediated by leaf litter depth, soil pH, and plant species richness. The high dispersal potential, annual, barochorous, and zoochorous plant species were the functional traits more affected by the eucalypt plantations. We recommend two management practices: reducing forest densities to allow higher light input to the understory and, due to the fact that leaf litter was negatively associated with all diversity facets, we recommend reducing their accumulation or generate heterogeneity in its distribution to enhance biodiversity.


2021 ◽  
Author(s):  
Prímula Campos ◽  
Carlos Ernesto Schaefer ◽  
Vanessa Pontara ◽  
Márcio Xavier ◽  
José Frutuoso Vale Júnior ◽  
...  

Abstract Understanding how environmental drivers induce changes in plant composition and diversity across evolutionary time can provide important insights into the mechanisms of community assembly. We evaluated how taxonomic and phylogenetic diversity and structure of plant communities change along a local-scale edaphic and topographic gradient in the Tepequém table mountain, Brazilian Amazon. We selected three phytophysiognomies along the altitudinal gradient: Open Rupestrian Grassland, Shrubby Rupestrian Grassland, and Forest. We compared community composition and taxonomic and phylogenetic diversity between phytophysiognomies, and we tested regression linear effect models to investigate the effect of altitude and soil properties on taxonomic and phylogenetic diversity. The highest species richness and phylogenetic diversity were found at lower elevation for Forest. Mean pairwise phylogenetic distance, mean nearest taxon phylogenetic distance, and all standardised phylogenetic metrics were significantly lower in Shrubby Rupestrian Grassland. This phytophysiognomy showed phylogenetic clustering. Forest showed a cluster pattern when only terminal nodes are considered and random dispersion to deep phylogenetic nodes. Open Rupestrian Grassland also showed random phylogenetic structure. The regression analyses showed that species richness and different phylogenetic diversity metrics were explained by altitude and soil properties. However, standardised metrics were not explained by these environmental variables. Comprehensive studies including the role of environmental drivers in plant evolutionary history along the altitudinal gradient are necessary for explaining community assembly patterns and provide additional information for conservation planning.


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