scholarly journals Truffles in the sky: the impact of stochastic and deterministic drivers on Rhizopogon communities of the Madrean Sky Island Archipelago

2021 ◽  
Author(s):  
Carolina Piña Páez ◽  
Adam Carson ◽  
Daniel Luoma ◽  
Joseph Spatafora
Keyword(s):  
Sonoran Desert ◽  
Geographic Distance ◽  
Niche Partitioning ◽  
Sky Islands ◽  
Root Tips ◽  
Island Effect ◽  
Demographic Processes ◽  
Madrean Sky Islands ◽  
Sky Island ◽  
The Impact

The Madrean Sky Islands Archipelago (MSIA) comprises mountain “islands” whose Pine-Oak forests appear in stark contrast to the surrounding “sea” of Sonoran Desert vegetation. Rhizopogon (Boletales) consists of obligate ectomycorrhizal (EcM) symbionts that form truffle sporocarps and associate exclusively with Pinaceae. The objectives of this project were to describe the diversity of species of Rhizopogon across the MSIA and to characterize whether community structure is determined by host diversity, island identity, geographic distance, or some interaction among these factors. We selected nine islands, two sites were sampled per island: one site dominated by Pinus species and the other by Pseudotsuga menziesii var. glauca. Rhizopogon diversity was characterized from sporocarps and from bioassay-based EcM root tips derived from P. muricata, Ps. menziesii var. menziesii, and Ps. menziesii var. glauca seedlings inoculated with soil samples collected along transects established at each site. The ITS rDNA fungal barcode was amplified, and sequences were used in community analyses. Twenty-one 99% OTUs in the genus Rhizopogon were identified across nine sky islands. While differential host association with Pinus and Pseudotsuga is a significant driver of community composition, our results supported a stronger island effect. Furthermore, Rhizopogon communities associated within hosts are characterized by random phylogenetic structures across sky islands and are not structured by geographic distance. These results are consistent with a strong isolation effect involving historical habitat fragmentation of sky islands in response to past climate changes, and that both niche partitioning and stochastic demographic processes function in shaping Rhizopogon communities of the MSIA.

scholarly journals The role of historical factors and natural selection in the evolution of breeding systems of Oxalis alpina in the Sonoran desert ‘Sky Islands’

2010 ◽  
Vol 23 (10) ◽  
pp. 2163-2175 ◽  
Author(s):  
J. PÉREZ-ALQUICIRA ◽  
F. E. MOLINA-FREANER ◽  
D. PIÑERO ◽  
S. G. WELLER ◽  
E. MARTÍNEZ-MEYER ◽  
...  
Keyword(s):  
Natural Selection ◽  
Sonoran Desert ◽  
Breeding Systems ◽  
Sky Islands ◽  
Historical Factors

scholarly journals Biodiversity conservation in the Madrean sky islands: community homogeneity of medium and large mammals in northwestern Mexico

2018 ◽  
Vol 99 (2) ◽  
pp. 465-477 ◽  
Author(s):  
Helí Coronel-Arellano ◽  
Nalleli E Lara-Díaz ◽  
Claudia E Moreno ◽  
Carmina E Gutiérrez-González ◽  
Carlos A López-González
Keyword(s):  
Biodiversity Conservation ◽  
Sky Islands ◽  
Large Mammals ◽  
Northwestern Mexico ◽  
Madrean Sky Islands

scholarly journals Sensory-based niche partitioning in a multiple predator–multiple prey community

2015 ◽  
Vol 282 (1808) ◽  
pp. 20150520 ◽  
Author(s):  
Jay J. Falk ◽  
Hannah M. ter Hofstede ◽  
Patricia L. Jones ◽  
Marjorie M. Dixon ◽  
Paul A. Faure ◽  
...  
Keyword(s):  
Species Interactions ◽  
Prey Species ◽  
Niche Partitioning ◽  
Signal Evolution ◽  
Signal Design ◽  
Predator Species ◽  
Mate Attraction ◽  
Communication Signals ◽  
Signal Features ◽  
The Impact

Many predators and parasites eavesdrop on the communication signals of their prey. Eavesdropping is typically studied as dyadic predator–prey species interactions; yet in nature, most predators target multiple prey species and most prey must evade multiple predator species. The impact of predator communities on prey signal evolution is not well understood. Predators could converge in their preferences for conspicuous signal properties, generating competition among predators and natural selection on particular prey signal features. Alternatively, predator species could vary in their preferences for prey signal properties, resulting in sensory-based niche partitioning of prey resources. In the Neotropics, many substrate-gleaning bats use the mate-attraction songs of male katydids to locate them as prey. We studied mechanisms of niche partitioning in four substrate-gleaning bat species and found they are similar in morphology, echolocation signal design and prey-handling ability, but each species preferred different acoustic features of male song in 12 sympatric katydid species. This divergence in predator preference probably contributes to the coexistence of many substrate-gleaning bat species in the Neotropics, and the substantial diversity in the mate-attraction signals of katydids. Our results provide insight into how multiple eavesdropping predator species might influence prey signal evolution through sensory-based niche partitioning.

scholarly journals Sustainable Site System

2021 ◽  
Author(s):  
Jorden J. S. Lefler
Keyword(s):  
Urban Area ◽  
Urban Areas ◽  
Architectural Design ◽  
Heat Island ◽  
Rating Systems ◽  
Island Effect ◽  
Key Points ◽  
Site Design ◽  
The Impact ◽  
The City

This thesis discusses a method of analysing the input of interventions in a building's site design, all of which affect the heat island effect, bio-diversity and hydrology of urban areas. Existing standards from Toronto, Vancouver and Berlin have been researched and analysed. This paper presents an evolution of a method called biotope area factor used in Berlin, Germany. A synthesis of the approach of all three systems was considered and distilled into the key points which were then incorporated into the proposed method. In addition to the impact of an individual building, it also includes the impact from the adjacent street area. The final components of this thesis are the application of the method developed to an urban area in the city of Toronto and results showing the impacts on architectural design from site rating systems.

scholarly journals Mutation load dynamics during environmentally-driven range shifts

2018 ◽  
Author(s):  
Kimberly J. Gilbert ◽  
Stephan Peischl ◽  
Laurent Excoffier
Keyword(s):  
Environmental Change ◽  
Geographic Distance ◽  
Species Range ◽  
Range Shifts ◽  
Strong Impact ◽  
Generalist Species ◽  
Deleterious Alleles ◽  
Species Survival ◽  
Specialist Species ◽  
The Impact

AbstractThe fitness of spatially expanding species has been shown to decrease over time and space, but specialist species tracking their changing environment and shifting their range accordingly have been little studied. We use individual-based simulations and analytical modeling to compare the impact of range expansions and range shifts on genetic diversity and fitness loss, as well as the ability to recover fitness after either a shift or expansion. We find that the speed of a shift has a strong impact on fitness evolution. Fastest shifts show the strongest fitness loss per generation, but intermediate shift speeds lead to the strongest fitness loss per geographic distance. Range shifting species lose fitness more slowly through time than expanding species, however, their fitness compared at equivalent geographic distances spread can be considerably lower. These counter-intuitive results arise from the combination of time over which selection acts and mutations enter the system. Range shifts also exhibit reduced fitness recovery after a geographic shift and may result in extinction, whereas range expansions can persist from the core of the species range. The complexity of range expansions and range shifts highlights the potential for severe consequences of environmental change on species survival.Author SummaryAs environments change through time across the globe, species must adapt or relocate to survive. Specialized species must track the specific moving environments to which they are adapted, as compared to generalists which can spread widely. During colonization of new habitat, individuals can accumulate deleterious alleles through repeated bottlenecks. We show through simulation and analytic modeling that the process by which these alleles accumulate changes depending upon the speed at which populations spread over a landscape. This is due to the increased efficacy of selection against deleterious variants at slow speeds of range shifts and decreased input of mutations at faster speeds of range shifts. Under some selective circumstances, shifting of a species range leads to extinction of the entire population. This suggests that the rate of environmental change across the globe will play a large role in the survival of specialist species as compared to more generalist species.

scholarly journals Microbial dark carbon fixation fueled by nitrate enrichment

2021 ◽  
Author(s):  
Joseph H. Vineis ◽  
Ashley N. Bulseco ◽  
Jennifer L. Bowen
Keyword(s):  
Microbial Communities ◽  
Marine Sediments ◽  
Salt Marshes ◽  
Carbon Fixation ◽  
Niche Partitioning ◽  
Coastal Marine Sediments ◽  
Functional Relationships ◽  
Coastal Marine ◽  
Dark Carbon Fixation ◽  
The Impact

Anthropogenic nitrate amendment to coastal marine sediments can increase rates of heterotrophic mineralization and autotrophic dark carbon fixation (DCF). DCF may be favored in sediments where organic matter is biologically unavailable, leading to a microbial community supported by chemoautotrophy. Niche partitioning among DCF communities and adaptations for nitrate metabolism in coastal marine sediments remain poorly characterized, especially within salt marshes. We used genome-resolved metagenomics, phylogenetics, and comparative genomics to characterize the potential niche space, phylogenetic relationships, and adaptations important to microbial communities within nitrate enriched sediment. We found that nitrate enrichment of sediment from discrete depths between 0-25 cm supported both heterotrophs and chemoautotrophs that use sulfur oxidizing denitrification to drive the Calvin-Benson-Bassham (CBB) or reductive TCA (rTCA) DCF pathways. Phylogenetic reconstruction indicated that the nitrate enriched community represented a small fraction of the phylogenetic diversity contained in coastal marine environmental genomes, while pangenomics revealed close evolutionary and functional relationships with DCF microbes in other oligotrophic environments. These results indicate that DCF can support coastal marine microbial communities and should be carefully considered when estimating the impact of nitrate on carbon cycling in these critical habitats.

scholarly journals The Consequences of the Military Conflict in Eastern Ukraine, Its Impact on International Investment Attractiveness, Economic and Demographic Development in Ukraine

2020 ◽  
Vol 11 (4) ◽  
pp. 81
Author(s):  
Dmytro Vasylkivskyi ◽  
Serhii Matiukh ◽  
Olha Matviiets ◽  
Ihor Lapshyn ◽  
Vitalina Babenko
Keyword(s):  
International Investment ◽  
Demographic Development ◽  
Economic Changes ◽  
Military Conflict ◽  
Development Indicators ◽  
Terrorist Groups ◽  
Demographic Processes ◽  
National Bank ◽  
The Military ◽  
The Impact

The conflict in the Eastern part of Ukraine and the growing geopolitical tensions have had a significant impact on the economy and society of the country. As a result, it deepened the recession and diverged from the planned development indicators. In particular, this concerns international reserves of the National Bank of Ukraine and the country's budget deficit. Multilateral economic changes, exacerbated by the impact of hostilities in the Eastern part of the country have transformed the structure of socio-demographic processes in Ukraine. Armed confrontation causes a continuous deterioration of demographic and economic indicators of development not only of Donetsk and Luhansk regions, but also has an impact on the whole country. This confrontation is also accompanied by the loss (destruction, theft, etc.) of public assets. The estimated cost of destroyed components of industrial, communal, social, transport, energy and other infrastructure are indicative due to the inability to inspect objects located within the territory controlled by terrorist groups. The conflict has also affected the investment attractiveness of the country, which accelerates the creation of a depressed nature of country’s development. Therefore, in the context of hostility in the Eastern Ukraine, it is important to understand and study its destabilizing impact, not only on domestic economic and demographic indicators, but also on the volume of foreign investment, which will allow us to understand the level of country’s involvement in the global investment space and the real impact of military action on the population and on international economic affairs of Ukraine. As a result of this scientific research, the population and GDP forecast have been conducted. It is worth noting that the forecast itself based on regression mathematical modelling which includes past data and can be accurate if current conditions are stable in the future.

Madrean Sky Islands, North America

2012 ◽  
pp. 217-226 ◽  
Author(s):  
Laura López-Hoffman ◽  
Adrian Quijada-Mascareñas
Keyword(s):  
North America ◽  
Sky Islands ◽  
Madrean Sky Islands
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