scholarly journals Everything you always wanted to know about gene flow in tropical landscapes (but were afraid to ask)

PeerJ ◽  
2019 ◽  
Vol 7 ◽  
pp. e6446 ◽  
Author(s):  
Waléria Pereira Monteiro ◽  
Jamille Costa Veiga ◽  
Amanda Reis Silva ◽  
Carolina da Silva Carvalho ◽  
Éder Cristian Malta Lanes ◽  
...  
Keyword(s):  
Gene Flow ◽  
Habitat Loss ◽  
Forest Cover ◽  
Habitat Degradation ◽  
Population Level ◽  
Tropical Species ◽  
Natural Habitats ◽  
Tropical Regions ◽  
Landscape Effects ◽  
Statistical Approaches

The bulk of the world’s biodiversity is found in tropical regions, which are increasingly threatened by the human-led degradation of natural habitats. Yet, little is known about tropical biodiversity responses to habitat loss and fragmentation. Here we review all available literature assessing landscape effects on gene flow in tropical species, aiming to help unravel the factors underpinning functional connectivity in the tropics. We map and classify studies by focus species, the molecular markers employed, statistical approaches to assess landscape effects on gene flow, and the evaluated landscape and environmental variables. We then compare qualitatively and quantitatively landscape effects on gene flow across species and units of analysis. We found 69 articles assessing landscape effects on gene flow in tropical organisms, most of which were published in the last five years, were concentrated in the Americas, and focused on amphibians or mammals. Most studies employed population-level approaches, microsatellites were the preferred type of markers, and Mantel and partial Mantel tests the most common statistical approaches used. While elevation, land cover and forest cover were the most common gene flow predictors assessed, habitat suitability was found to be a common predictor of gene flow. A third of all surveyed studies explicitly assessed the effect of habitat degradation, but only 14 of these detected a reduced gene flow with increasing habitat loss. Elevation was responsible for most significant microsatellite-based isolation by resistance effects and a single study reported significant isolation by non-forested areas in an ant. Our study reveals important knowledge gaps on the study of landscape effects on gene flow in tropical organisms, and provides useful guidelines on how to fill them.

scholarly journals Urbanization impacts apex predator gene flow but not genetic diversity across an urban-rural divide

2019 ◽  
Author(s):  
DR Trumbo ◽  
PE Salerno ◽  
KA Logan ◽  
M Alldredge ◽  
RB Gagne ◽  
...  
Keyword(s):  
Genetic Diversity ◽  
Gene Flow ◽  
Forest Cover ◽  
Puma Concolor ◽  
Population Connectivity ◽  
Population Substructure ◽  
Western Slope ◽  
Restricted Gene Flow ◽  
Front Range ◽  
Natural Habitats

AbstractApex predators are important indicators of intact natural ecosystems. They are also sensitive to urbanization because they require broad home ranges and extensive contiguous habitat to support their prey base. Pumas (Puma concolor) can persist near human developed areas, but urbanization may be detrimental to their movement ecology, population structure, and genetic diversity. To investigate potential effects of urbanization in population connectivity of pumas, we performed a landscape genomics study of 134 pumas on the rural Western Slope and more urbanized Front Range of Colorado, USA. Over 12,000 single nucleotide polymorphisms were genotyped using double-digest, restriction site-associated DNA sequencing (ddRADseq). We investigated patterns of gene flow and genetic diversity, and tested for correlations between key landscape variables and genetic distance to assess the effects of urbanization and other landscape factors on gene flow. Levels of genetic diversity were similar for the Western Slope and Front Range, but effective population sizes were smaller, genetic distances were higher, and there was more overall population substructure in the more urbanized Front Range. Forest cover was strongly positively associated with puma gene flow on the Western Slope, while impervious surfaces restricted gene flow and more open, natural habitats enhanced gene flow on the Front Range. Landscape genomic analyses revealed differences in puma movement and gene flow patterns in rural versus urban settings. Our results highlight the utility of dense, genome-scale markers to document subtle impacts of urbanization on a wide-ranging carnivore living near a large urban center.

scholarly journals Biodiversity Loss: Threats and Conservation Strategies

2021 ◽  
Vol 68 (1) ◽  
Author(s):  
Reeta Kumari ◽  
Deepali A ◽  
Sonal Bhatnagar
Keyword(s):  
Large Scale ◽  
Forest Cover ◽  
Agricultural Land ◽  
Habitat Degradation ◽  
Biodiversity Loss ◽  
Conservation Strategies ◽  
Natural Habitats ◽  
Conventional Agriculture ◽  
Holistic View ◽  
Global Population

The global population is expanding day by day, the increase in food demand by the growing population poses serious environmental challenges. To satisfy the increasing food supply, a shift in conventional agriculture was observed that lead to expanded agricultural land uses with reduced wildlife and biodiversity. Deterioration of agricultural land has caused overexploitation of forest land by converting natural habitats into managed systems. Life has originated billions of years ago. Since then, there is a continual extinction of over 90% of the species due to various factors such as increased human population, unsustainable resource consumption, habitat fragmentation, habitat degradation, alien species invasion, pollution, monoculture practices, climate change, loss of forest cover etc. Food, fodder, fuel, medicines, wood, crop plants are some of the natural resources received from the environment. Biodiversity also provides an ecosystem, social, and spiritual services to mankind. We must realize the significance of biodiversity on earth as a valuable resource that can help in developing new products for generations. A consensus has been developed to adopt a holistic view of biodiversity for its conservation and sustainable utilization. Numerous techniques have been proposed and implemented for the conservation of biodiversity and its genetic resources. Since we are dependent on nature for our livelihood, this review paper aims to address the biodiversity and its threats along with some conservation strategies which are not adopted on a large scale.

Systematics and evolution of Lentibulariaceae: III. Utricularia

2018 ◽  
Author(s):  
Richard W. Jobson ◽  
Paulo C. Baleeiro ◽  
Cástor Guisande
Keyword(s):  
Gene Flow ◽  
Species Diversity ◽  
Population Level ◽  
Oceanic Islands ◽  
Vulnerable Species ◽  
Phylogenetic Studies ◽  
Molecular Phylogenetic

Utricularia is a morphologically and ecologically diverse genus currently comprising more than 230 species divided into three subgenera—Polypompholyx, Utricularia, and Bivalvaria—and 35 sections. The genus is distributed worldwide except on the poles and most oceanic islands. The Neotropics has the highest species diversity, followed by Australia. Compared to its sister genera, Utricularia has undergone greater rates of speciation, which are linked to its extreme morphological flexibility that has resulted in the evolution of habitat-specific forms: terrestrial, rheophytic, aquatic, lithophytic, and epiphytic. Molecular phylogenetic studies have resolved relationships for 44% of the species across 80% of the sections. Scant data are available for phylogeography or population-level processes such as gene flow, hybridization, or pollination. Because nearly 90% of the species are endemics, data are urgently needed to determine how to protect vulnerable species and their habitats.

scholarly journals Evaluating Forest Cover and Fragmentation in Costa Rica with a Corrected Global Tree Cover Map

2020 ◽  
Vol 12 (19) ◽  
pp. 3226
Author(s):  
Daniel Cunningham ◽  
Paul Cunningham ◽  
Matthew E. Fagan
Keyword(s):  
Costa Rica ◽  
Forest Cover ◽  
Agricultural Land ◽  
Forest Area ◽  
Tree Cover ◽  
Agricultural Crop ◽  
Forest Change ◽  
Alos Palsar ◽  
Tropical Regions ◽  
The Impact

Global tree cover products face challenges in accurately predicting tree cover across biophysical gradients, such as precipitation or agricultural cover. To generate a natural forest cover map for Costa Rica, biases in tree cover estimation in the most widely used tree cover product (the Global Forest Change product (GFC) were quantified and corrected, and the impact of map biases on estimates of forest cover and fragmentation was examined. First, a forest reference dataset was developed to examine how the difference between reference and GFC-predicted tree cover estimates varied along gradients of precipitation and elevation, and nonlinear statistical models were fit to predict the bias. Next, an agricultural land cover map was generated by classifying Landsat and ALOS PalSAR imagery (overall accuracy of 97%) to allow removing six common agricultural crops from estimates of tree cover. Finally, the GFC product was corrected through an integrated process using the nonlinear predictions of precipitation and elevation biases and the agricultural crop map as inputs. The accuracy of tree cover prediction increased by ≈29% over the original global forest change product (the R2 rose from 0.416 to 0.538). Using an optimized 89% tree cover threshold to create a forest/nonforest map, we found that fragmentation declined and core forest area and connectivity increased in the corrected forest cover map, especially in dry tropical forests, protected areas, and designated habitat corridors. By contrast, the core forest area decreased locally where agricultural fields were removed from estimates of natural tree cover. This research demonstrates a simple, transferable methodology to correct for observed biases in the Global Forest Change product. The use of uncorrected tree cover products may markedly over- or underestimate forest cover and fragmentation, especially in tropical regions with low precipitation, significant topography, and/or perennial agricultural production.

scholarly journals Analysing landscape effects on dispersal networks and gene flow with genetic graphs

2021 ◽  
Author(s):  
Paul Savary ◽  
Jean‐Christophe Foltête ◽  
Hervé Moal ◽  
Gilles Vuidel ◽  
Stéphane Garnier
Keyword(s):  
Gene Flow ◽  
Landscape Effects

Inferring landscape effects on gene flow: a new model selection framework

2010 ◽  
Vol 19 (17) ◽  
pp. 3603-3619 ◽  
Author(s):  
A. J. SHIRK ◽  
D. O. WALLIN ◽  
S. A. CUSHMAN ◽  
C. G. RICE ◽  
K. I. WARHEIT
Keyword(s):  
Gene Flow ◽  
Model Selection ◽  
New Model ◽  
Landscape Effects ◽  
Selection Framework

Relationships between gregarine infection in damselflies, wetland type, and landscape characteristics

2011 ◽  
Vol 143 (5) ◽  
pp. 460-469 ◽  
Author(s):  
Julia J. Mlynarek ◽  
Daniel G. Bert ◽  
G. Haydeé Peralta-Vázquez ◽  
Joanna A. James ◽  
Mark R. Forbes
Keyword(s):  
Forest Cover ◽  
Road Density ◽  
Natural Habitats ◽  
Artificial Wetlands ◽  
Wetland Type ◽  
Landscape Characteristics ◽  
Natural Wetlands ◽  
Ischnura Verticalis ◽  
Host Parasite ◽  
Wetland Cover

AbstractAlthough human-modified landscapes are characterized by the loss of natural habitats, new habitats also can be created and exploited by many species. The importance of landscape change to invertebrate associations (particularly host-parasite associations) is understudied. Our objective was to determine whether prevalence and intensity of gregarine parasitism in the damselfly Ischnura verticalis (Say) (Odonata: Coenagrionidae) differed between 17 artificial and 7 natural wetlands in landscapes that varied in amount of forest and wetland cover and road density determined at spatial extents of 500m and 1km from each wetland. Wetlands were located in and around Ottawa, Ontario, and Gatineau, Quebec, Canada. Wetland type did not account for significant variation in principal components based on forest and wetland cover and road density at either spatial extent. Gregarine prevalence was higher in damselflies collected from natural wetlands than in those collected from artificial wetlands and was positively associated with increasing forest cover. In contrast, gregarine intensity was inversely related to road density. Our results suggest that parasitism of damselflies by gregarines is associated with wetland type and landscape characteristics, although the mechanisms producing such relationships are unknown.

scholarly journals THE SOCIALIST REPUBLIC OF VIETNAM IN THE INTERNATIONAL MARKETS OF AQUACULTURE PRODUCTS

2021 ◽  
pp. 96-99
Author(s):  
Vladimir Grigor'ev ◽  
Dan Chuong Fam Thi ◽  
Rustam Nizamov ◽  
Igor' Grigor'ev
Keyword(s):  
Forest Cover ◽  
Natural Habitat ◽  
Strong Dependence ◽  
World Market ◽  
Natural Ecosystems ◽  
Natural Conditions ◽  
Natural Habitats ◽  
Socialist Republic ◽  
National University ◽  
The Government

Aquaculture is one of the most promising and dynamically developing types of agricultural production, especially in countries with warm climates. The research was carried out to analyze the current situation in aquaculture in Vietnam to clarify the existing problems and prospects of this industry. When collecting materials, we used statistical data from the Government of the Socialist Republic of Vietnam, as well as information from representatives of the Institute of Economics and Business of the Vietnam National University (Hanoi). In the Socialist Republic of Vietnam, aquaculture is well developed and continues to actively expand, annually increasing the production of products that are in significant demand on the world market. One of the most important problems of the industry is the threat to natural biodiversity, primarily due to the reduction of the natural habitats of the inhabitants of rivers and mangroves. An equally important problem is the strong dependence of the production of products, primarily shrimp, on foreign markets, which today is objective and insurmountable. Due to the use of chemicals and antibiotics in aquaculture, especially in natural conditions, environmental degradation is possible. Among the promising areas for the development of the industry is the convergence of natural ecosystems and agriculture, a good example of which is the cultivation of shrimp in mangroves without destroying the forest cover. It is possible to switch to aquaculture as an adaptation to changes in the ecological situation, primarily to the salinization of river deltas. As a result of a decrease in the profitability of fishing in the natural habitat of fish and shrimps, an increase in their populations in natural conditions is possible

scholarly journals Extinction risk of narrowly distributed species of seed plants in Brazil due to habitat loss and climate change

PeerJ ◽  
2019 ◽  
Vol 7 ◽  
pp. e7333 ◽  
Author(s):  
José Maria Cardoso da Silva ◽  
Alessandro Rapini ◽  
Luis Cláudio F. Barbosa ◽  
Roger R. Torres
Keyword(s):  
Climate Change ◽  
Land Use ◽  
Habitat Loss ◽  
Extinction Risk ◽  
Conservation Strategies ◽  
Seed Plants ◽  
Conservation Action ◽  
Species Extinction ◽  
Tropical Regions ◽  
Mitigation And Adaptation

In a world where changes in land cover and climate happen faster than ever due to the expansion of human activities, narrowly distributed species are predicted to be the first to go extinct. Studies projecting species extinction in tropical regions consider either habitat loss or climate change as drivers of biodiversity loss but rarely evaluate them together. Here, the contribution of these two factors to the extinction risk of narrowly distributed species (with ranges smaller than 10,000 km2) of seed plants endemic to a fifth-order watershed in Brazil (microendemics) is assessed. We estimated the Regional Climate Change Index (RCCI) of these watersheds (areas with microendemics) and projected three scenarios of land use up to the year 2100 based on the average annual rates of habitat loss in these watersheds from 2000 to 2014. These scenarios correspond to immediate conservation action (scenario 1), long-term conservation action (scenario 2), and no conservation action (scenario 3). In each scenario, areas with microendemics were classified into four classes: (1) areas with low risk, (2) areas threatened by habitat loss, (3) areas threatened by climate change, and (4) areas threatened by climate change and habitat loss. We found 2,354 microendemic species of seed plants in 776 areas that altogether cover 17.5% of Brazil. Almost 70% (1,597) of these species are projected to be under high extinction risk by the end of the century due to habitat loss, climate change, or both, assuming that these areas will not lose habitat in the future due to land use. However, if habitat loss in these areas continues at the prevailing annual rates, the number of threatened species is projected to increase to more than 85% (2,054). The importance of climate change and habitat loss as drivers of species extinction varies across phytogeographic domains, and this variation requires the adoption of retrospective and prospective conservation strategies that are context specific. We suggest that tropical countries, such as Brazil, should integrate biodiversity conservation and climate change policies (both mitigation and adaptation) to achieve win-win social and environmental gains while halting species extinction.

scholarly journals Bees use anthropogenic habitats despite strong natural habitat preferences

2018 ◽  
Author(s):  
Miguel Á. Collado ◽  
Daniel Sol ◽  
Ignasi Bartomeus
Keyword(s):  
Habitat Loss ◽  
Natural Habitat ◽  
Habitat Preferences ◽  
Abundant Species ◽  
Comprehensive Analysis ◽  
Natural Habitats ◽  
Large Dataset ◽  
Anthropogenic Habitats ◽  
Bee Diversity ◽  
Northeast Usa

ABSTRACTHabitat loss and alteration is widely considered one of the main drivers of the current loss of pollinator diversity. Unfortunately, we still lack a comprehensive analysis of habitat importance, use and preference for major groups of pollinators. Here, we address this gap analysing a large dataset of 15,762 bee specimens (more than 400 species) across northeast USA. We found that natural habitats sustain the highest bee diversity, with many species strongly depending on such habitats. By characterizing habitat use and preference for the 45 most abundant species, we also show that many bee species can use human-altered habitats despite exhibiting strong and clear preferences for forested habitats. However, only a few species appear to do well when the habitat has been drastically modified. We conclude that although altered environments may harbor a substantial number of species, preserving natural areas is still essential to guarantee the conservation of bee biodiversity.

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