scholarly journals Disentangling the latitudinal and altitudinal shifts in community composition induced by climate change: The case of riparian birds

2020 ◽  
Author(s):  
Elie Gaget ◽  
Vincent Devictor ◽  
Bernard Frochot ◽  
Régis Desbrosses ◽  
Marie‐Christine Eybert ◽  
...  
2020 ◽  
Vol 637 ◽  
pp. 159-180
Author(s):  
ND Gallo ◽  
M Beckwith ◽  
CL Wei ◽  
LA Levin ◽  
L Kuhnz ◽  
...  

Natural gradient systems can be used to examine the vulnerability of deep-sea communities to climate change. The Gulf of California presents an ideal system for examining relationships between faunal patterns and environmental conditions of deep-sea communities because deep-sea conditions change from warm and oxygen-rich in the north to cold and severely hypoxic in the south. The Monterey Bay Aquarium Research Institute (MBARI) remotely operated vehicle (ROV) ‘Doc Ricketts’ was used to conduct seafloor video transects at depths of ~200-1400 m in the northern, central, and southern Gulf. The community composition, density, and diversity of demersal fish assemblages were compared to environmental conditions. We tested the hypothesis that climate-relevant variables (temperature, oxygen, and primary production) have more explanatory power than static variables (latitude, depth, and benthic substrate) in explaining variation in fish community structure. Temperature best explained variance in density, while oxygen best explained variance in diversity and community composition. Both density and diversity declined with decreasing oxygen, but diversity declined at a higher oxygen threshold (~7 µmol kg-1). Remarkably, high-density fish communities were observed living under suboxic conditions (<5 µmol kg-1). Using an Earth systems global climate model forced under an RCP8.5 scenario, we found that by 2081-2100, the entire Gulf of California seafloor is expected to experience a mean temperature increase of 1.08 ± 1.07°C and modest deoxygenation. The projected changes in temperature and oxygen are expected to be accompanied by reduced diversity and related changes in deep-sea demersal fish communities.


2021 ◽  
Vol 53 (1) ◽  
pp. 135-148
Author(s):  
Christopher J. Ellis ◽  
Sally Eaton

AbstractThere is growing evidence that species and communities are responding to, and will continue to be affected by, climate change. For species at risk, vulnerability can be reduced by ensuring that their habitat is extensive, connected and provides opportunities for dispersal and/or gene flow, facilitating a biological response through migration or adaptation. For woodland epiphytes, vulnerability might also be reduced by ensuring sufficient habitat heterogeneity, so that microhabitats provide suitable local microclimates, even as the larger scale climate continues to change (i.e. microrefugia). This study used fuzzy set ordination to compare bryophyte and lichen epiphyte community composition to a large-scale gradient from an oceanic to a relatively more continental macroclimate. The residuals from this relationship identified microhabitats in which species composition reflected a climate that was more oceanic or more continental than would be expected given the prevailing macroclimate. Comparing these residuals to features that operate at different scales to create the microclimate (landscape, stand and tree-scale), it was possible to identify how one might engineer microrefugia into existing or new woodland, in order to reduce epiphyte vulnerability to climate change. Multimodel inference was used to identify the most important features for consideration, which included local effects such as height on the bole, angle of bole lean and bark water holding capacity, as well as tree species and tree age, and within the landscape, topographic wetness and physical exposure.


2021 ◽  
Vol 12 ◽  
Author(s):  
Lucas Fillinger ◽  
Kerstin Hürkamp ◽  
Christine Stumpp ◽  
Nina Weber ◽  
Dominik Forster ◽  
...  

Understanding microbial community dynamics in the alpine cryosphere is an important step toward assessing climate change impacts on these fragile ecosystems and meltwater-fed environments downstream. In this study, we analyzed microbial community composition, variation in community alpha and beta diversity, and the number of prokaryotic cells and virus-like particles (VLP) in seasonal snowpack from two consecutive years at three high altitude mountain summits along a longitudinal transect across the European Alps. Numbers of prokaryotic cells and VLP both ranged around 104 and 105 per mL of snow meltwater on average, with variation generally within one order of magnitude between sites and years. VLP-to-prokaryotic cell ratios spanned two orders of magnitude, with median values close to 1, and little variation between sites and years in the majority of cases. Estimates of microbial community alpha diversity inferred from Hill numbers revealed low contributions of common and abundant microbial taxa to the total taxon richness, and thus low community evenness. Similar to prokaryotic cell and VLP numbers, differences in alpha diversity between years and sites were generally relatively modest. In contrast, community composition displayed strong variation between sites and especially between years. Analyses of taxonomic and phylogenetic community composition showed that differences between sites within years were mainly characterized by changes in abundances of microbial taxa from similar phylogenetic clades, whereas shifts between years were due to significant phylogenetic turnover. Our findings on the spatiotemporal dynamics and magnitude of variation of microbial abundances, community diversity, and composition in surface snow may help define baseline levels to assess future impacts of climate change on the alpine cryosphere.


2016 ◽  
Vol 23 (3) ◽  
pp. 1023-1035 ◽  
Author(s):  
Remy R. Okazaki ◽  
Erica K. Towle ◽  
Ruben van Hooidonk ◽  
Carolina Mor ◽  
Rivah N. Winter ◽  
...  

2020 ◽  
Author(s):  
Kathrin Rousk

&lt;p&gt;Nitrogen (N&lt;sub&gt;2&lt;/sub&gt;) fixation performed by moss-associated cyanobacteria is one of the main sources of new N in pristine, high latitude ecosystems like boreal forests and arctic tundra. Here, mosses and associated cyanobacteria can contribute more than 50% to total ecosystem N input. However, N&lt;sub&gt;2&lt;/sub&gt; fixation in mosses is strongly influenced by abiotic factors, in particular moisture and temperature. Hence, climate change will significantly affect this key ecosystem process in pristine ecosystems. Here,&amp;#160;I will present a synthesis of several field and laboratory assessments of moss-associated N&lt;sub&gt;2&lt;/sub&gt; fixation in response to climate change by manipulating moisture and temperature in subarctic and arctic tundra.&lt;/p&gt;&lt;p&gt;Both in a long-term climate warming experiment in the arctic, and along a continental climate gradient, spanning arctic, subarctic and temperate ecosystems, increased temperatures (up to 30 &amp;#176;C) lead to either no effect or decreased N&lt;sub&gt;2&lt;/sub&gt; fixation rates in different moss species. Yet, N&lt;sub&gt;2&lt;/sub&gt; fixation rates were strongly dependent on moss-moisture, which seems to be a more important driver of N&lt;sub&gt;2&lt;/sub&gt; fixation in mosses than temperature.&lt;/p&gt;&lt;p&gt;In another set of studies, two dominant moss species (Hylocomium splendens, Pleurozium schreberi) were collected from a steep precipitation gradient (400-1200 mm mean annual precipitation, MAP) in the Subarctic close to Abisko, Northern Sweden, and were incubated at different moisture and temperature levels in the laboratory. Nitrogen fixation, cyanobacterial abundance (via qPCR) and cyanobacterial community composition (via sequencing) on the mosses were assessed. Moisture and temperature interacted strongly to control moss-associated N&lt;sub&gt;2&lt;/sub&gt; fixation rates, and the highest activity was found at the wet end of the precipitation gradient. Although cyanobacterial abundance was higher in one of the investigated mosses (H. splendens), translating into higher N&lt;sub&gt;2&lt;/sub&gt; fixation rates, cyanobacterial community composition did not differ between the two moss species. Nostoc was the most common cyanobacterial genera on both mosses, and hardly any methanotrophic N&lt;sub&gt;2&lt;/sub&gt; fixing bacteria were found on the mosses along the precipitation gradient. Increased temperatures lead to increased abundances of certain cyanobacterial genera (Cylindrospermum and Nostoc), while others declined in response to warming. Hence, cyanobacterial communities colonizing mosses will be dominated by a few cyanobacteria species in a warmer climate, and temperature and moisture interact strongly to affect their activity. Thus, these two major climate change factors should be considered in unison when estimating climate change effects on key ecosystem processes such as N&lt;sub&gt;2&lt;/sub&gt; fixation. Further, host identity determines cyanobacterial abundance, and thereby, N&lt;sub&gt;2&lt;/sub&gt; fixation rates.&lt;/p&gt;&lt;p&gt;&amp;#160;&lt;/p&gt;&lt;p&gt;&amp;#160;&lt;/p&gt;&lt;p&gt;&amp;#160;&lt;/p&gt;


mSystems ◽  
2021 ◽  
Author(s):  
Guillaume Bay ◽  
Conard Lee ◽  
Chiliang Chen ◽  
Navreet K. Mahal ◽  
Michael J. Castellano ◽  
...  

Crops in simplified, low-diversity agroecosystems assimilate only a fraction of the inorganic nitrogen (N) fertilizer inputs. Much of this N fertilizer is lost to the environment as N oxides, which degrade water quality and contribute to climate change and loss of biodiversity.


2021 ◽  
Vol 12 ◽  
Author(s):  
József Geml ◽  
Luis N. Morgado ◽  
Tatiana A. Semenova-Nelsen

The arctic tundra is undergoing climate-driven changes and there are serious concerns related to the future of arctic biodiversity and altered ecological processes under possible climate change scenarios. Arctic land surface temperatures and precipitation are predicted to increase further, likely causing major transformation in terrestrial ecosystems. As a response to increasing temperatures, shifts in vegetation and soil fungal communities have already been observed. Little is known, however, how long-term experimental warming coupled with increased snow depth influence the trajectories of soil fungal communities in different tundra types. We compared edaphic variables and fungal community composition in experimental plots simulating the expected increase in summer warming and winter snow depth, based on DNA metabarcoding data. Fungal communities in the sampled dry and moist acidic tundra communities differed greatly, with tundra type explaining ca. one-third of compositional variation. Furthermore, dry and moist tundra appear to have different trajectories in response to climate change. Specifically, while both warming and increased snow depth had significant effects on fungal community composition and edaphic variables in dry tundra, the effect of increased snow was greater. However, in moist tundra, fungal communities mainly were affected by summer warming, while increased snow depth had a smaller effect and only on some functional groups. In dry tundra, microorganisms generally are limited by moisture in the summer and extremely low temperatures in winter, which is in agreement with the stronger effect of increased snow depth relative to warming. On the contrary, moist tundra soils generally are saturated with water, remain cold year-round and show relatively small seasonal fluctuations in temperature. The greater observed effect of warming on fungi in moist tundra may be explained by the narrower temperature optimum compared to those in dry tundra.


2019 ◽  
Vol 15 (7) ◽  
pp. 20190280 ◽  
Author(s):  
Gabrielle Martin ◽  
Vincent Devictor ◽  
Eric Motard ◽  
Nathalie Machon ◽  
Emmanuelle Porcher

Latitudinal and altitudinal range shifts in response to climate change have been reported for numerous animal species, especially those with high dispersal capacities. In plants, the impact of climate change on species distribution or community composition has been documented mainly over long periods (decades) and in specific habitats, often forests. Here, we broaden the results of such long-term, focused studies by examining climate-driven changes in plant community composition over a large area (France) encompassing multiple habitat types and over a short period (2009–2017). To this end, we measured mean community thermal preference, calculated as the community-weighted mean of the Ellenberg temperature indicator value, using data from a standardized participatory monitoring scheme. We report a rapid increase in the mean thermal preference of plant communities at national and regional scales, which we relate to climate change. This reshuffling of plant community composition corresponds to a relative increase in the abundance of warm- versus cold-adapted species. However, support for this trend was weaker when considering only the common species, including common annuals. Our results thus suggest for the first time that the response of plant communities to climate change involves subtle changes affecting all species rare and common, which can nonetheless be detected over short time periods. Whether such changes are sufficient to cope with the current climate warming remains to be ascertained.


2020 ◽  
Vol 96 (12) ◽  
Author(s):  
An Bui ◽  
Devyn Orr ◽  
Michelle Lepori-Bui ◽  
Kelli Konicek ◽  
Hillary S Young ◽  
...  

ABSTRACT A large part of ecosystem function in woodland systems depends on soil fungal communities. However, global climate change has the potential to fundamentally alter these communities as fungal species are filtered with changing environmental conditions. In this study, we examined the potential effects of climate on host-associated (i.e. tree-associated) soil fungal communities at climatically distinct sites in the Tehachapi Mountains in California, where more arid conditions represent likely regional climate futures. We found that soil fungal community composition changes strongly across sites, with species richness and diversity being highest at the most arid site. However, host association may buffer the effects of climate on community composition, as host-associated fungal communities are more similar to each other across climatically distinct sites than the whole fungal community. Lastly, an examination of functional traits for ectomycorrhizal fungi, a well-studied guild of fungal mutualist species, showed that stress-tolerant traits were more abundant at arid sites than mesic sites, providing a mechanistic understanding of these community patterns. Taken together, our results indicate that fungal community composition will likely shift with future climate change but that host association may buffer these effects, with shifts in functional traits having implications for future ecosystem function.


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