Spatial variation in vegetation and abiotic factors related to the occurrence of a ring‐forming sedge

2002 ◽  
Vol 13 (5) ◽  
pp. 677-684 ◽  
Author(s):  
Sofie Wikberg ◽  
Ladislav Mucina
Keyword(s):  
Spatial Variation ◽  
Abiotic Factors

Small-scale heterogeneity in temperate forest canopy arthropods: stratification of spider and beetle assemblages

2012 ◽  
Vol 144 (4) ◽  
pp. 526-537 ◽  
Author(s):  
Kathleen R. Aikens ◽  
Christopher M. Buddle
Keyword(s):  
Spatial Variation ◽  
Acer Saccharum ◽  
Forest Canopy ◽  
Deciduous Forest ◽  
Abiotic Factors ◽  
Small Scale ◽  
Eastern Canada ◽  
Sugar Maples ◽  
Beetle Assemblages ◽  
The Vertical Distribution

AbstractVertical gradients in biotic and abiotic factors may create small-scale spatial variation in arthropod communities, a phenomenon that continues to be understudied. We investigated heterogeneity in the vertical distribution of spider and beetle assemblages in the canopy of sugar maples (Acer saccharum Marshall) (Aceraceae) in a deciduous forest in eastern Canada. Comparisons across four strata (understorey [UN] through upper canopy [UC] crown) documented variation in density, diversity, and species composition. Density of all common families decreased significantly with height and overall species richness of both spiders and beetles was highest in the UN and lowest in the UC crown. We observed greater spatial variation in spider assemblages compared with beetle assemblages and documented differences in spider guild structure: web-spinning spiders were most common in the UN and jumping spiders dominated the canopy. Our results suggest that arthropod assemblages are not homogeneous with respect to vertical space and that heterogeneity exists even at the scale of several metres.

scholarly journals Disease swamps molecular signatures of genetic-environmental associations to abiotic factors in Tasmanian devil (Sarcophilus harrisii) populations

2019 ◽  
Author(s):  
Alexandra K. Fraik ◽  
Mark J. Margres ◽  
Brendan Epstein ◽  
Soraia Barbosa ◽  
Menna Jones ◽  
...  
Keyword(s):  
Spatial Variation ◽  
Local Adaptation ◽  
Environmental Variables ◽  
Abiotic Factors ◽  
Rapid Onset ◽  
Tasmanian Devil ◽  
Landscape Genomics ◽  
Abiotic Environment ◽  
Candidate Loci ◽  
Sarcophilus Harrisii

AbstractLandscape genomics studies focus on identifying candidate genes under selection via spatial variation in abiotic environmental variables, but rarely by biotic factors such as disease. The Tasmanian devil (Sarcophilus harrisii) is found only on the environmentally heterogeneous island of Tasmania and is threatened with extinction by a nearly 100% fatal, transmissible cancer, devil facial tumor disease (DFTD). Devils persist in regions of long-term infection despite epidemiological model predictions of species’ extinction, suggesting possible adaptation to DFTD. Here, we test the extent to which spatial variation and genetic diversity are associated with the abiotic environment and/or by DFTD. We employ genetic-environment association (GEAs) analyses using a RAD-capture panel consisting of 6,886 SNPs from 3,286 individuals sampled pre- and post-disease arrival. Pre-disease, we find significant correlations of allele frequencies with environmental variables, including 349 unique loci linked to 64 genes, suggesting local adaptation to abiotic environment. Following DFTD arrival, however, we detected few of the pre-disease candidate loci, but instead frequencies of candidate loci linked to 14 genes correlated with disease prevalence. Loss of apparent signal of abiotic local adaptation following disease arrival suggests swamping by the strong selection imposed by DFTD. Further support for this result comes from the fact that post-disease candidate loci are in linkage disequilibrium with genes putatively involved in immune response, tumor suppression and apoptosis. This suggests the strength GEA associations of loci with the abiotic environment are swamped resulting from the rapid onset of a biotic selective pressure.

scholarly journals The use of indices for evaluating the periphytic community in two kinds of substrate in Imboassica Lagoon, Rio de Janeiro, Brazil

2003 ◽  
Vol 63 (2) ◽  
pp. 233-243 ◽  
Author(s):  
V. O. Fernandes ◽  
F. A. Esteves
Keyword(s):  
Spatial Variation ◽  
Nutrient Availability ◽  
Rio De Janeiro ◽  
Abiotic Factors ◽  
Dry Weight ◽  
Ash Content ◽  
Sampling Station ◽  
Typha Domingensis ◽  
Intermediate Period ◽  
The Difference

Biological indices based on the biomass (dry weight, ash content, and chlorophyll-a) of the periphyton in a natural (submersed leaves of Typha domingensis Pers) and in an artificial (plastic hoses) substrate were compared, in experiments performed in summer and winter, in two sampling stations of Imboassica Lagoon, Macaé, Rio de Janeiro. The periphytic community exhibited low biomass at the beginning and end of the experiments, and moderate biomass in the intermediate period of the experiment, whatever the kind of substrate, sampling station, and season. In both seasons, there was a spatial variation regarding the degree of trophy of the periphyton, due to the difference of nutrient availability among the sampling stations. The alternation of inorganic and organic periphyton, as well as of their heterotrophic, hetero-autotrophic, auto-heterotrophic and, autotrophic character was due to changes in the abiotic factors of the sampling periods. The Lakatos index proved more sensitive than the Autotrophic Index to variations in the composition of the periphytic community.

scholarly journals Global topographic uplift has elevated speciation in mammals and birds over the last 3 million years

2021 ◽  
Author(s):  
Javier Igea ◽  
Andrew J. Tanentzap
Keyword(s):  
Spatial Variation ◽  
Abiotic Factors ◽  
Habitat Diversity ◽  
Evolutionary Change ◽  
Habitat Connectivity ◽  
Direct Effects ◽  
Geological Processes ◽  
Global Biodiversity

AbstractTopographic change shapes the evolution of biodiversity by influencing both habitat connectivity and habitat diversity as well as abiotic factors like climate. However, its role in creating global biodiversity gradients remains poorly characterized because geology, climate and evolutionary data have rarely been integrated across concordant timescales. Here we show that topographic uplift over the last 3 million years explains more spatial variation in the speciation of all mammals and birds than do the direct effects of palaeoclimate change and both present-day elevation and present-day temperature. By contrast, the effects of topographic changes are much smaller than those of present-day temperatures in eroded areas. Together, our results stress that historical geological processes rather than traditionally studied macroecological gradients may ultimately generate much of the world’s biodiversity. More broadly, as the Earth’s surface continues to rise and fall, topography will remain an important driver of evolutionary change and novelty.

Relative contributions of biotic and abiotic factors to the spatial variation of litter stock in a mature subtropical forest

2019 ◽  
Vol 12 (4) ◽  
pp. 769-780 ◽  
Author(s):  
Jing Wang ◽  
Qingsong Yang ◽  
Yang Qiao ◽  
Deli Zhai ◽  
Lifen Jiang ◽  
...  
Keyword(s):  
Spatial Variation ◽  
Abiotic Factors ◽  
Subtropical Forest ◽  
Biotic And Abiotic Factors

Coral husbandry for ocean futures: leveraging abiotic factors to increase survivorship, growth, and resilience in juvenile Montipora capitata

2021 ◽  
Vol 657 ◽  
pp. 123-133
Author(s):  
JR Hancock ◽  
AR Barrows ◽  
TC Roome ◽  
AS Huffmyer ◽  
SB Matsuda ◽  
...  
Keyword(s):  
Abiotic Factors ◽  
Larval Rearing ◽  
Abiotic Conditions ◽  
Montipora Capitata ◽  
Reef Restoration ◽  
Juvenile Corals ◽  
Bleaching Response ◽  
The Face ◽  
Survival And Growth ◽  
Global And Local

Reef restoration via direct outplanting of sexually propagated juvenile corals is a key strategy in preserving coral reef ecosystem function in the face of global and local stressors (e.g. ocean warming). To advance our capacity to scale and maximize the efficiency of restoration initiatives, we examined how abiotic conditions (i.e. larval rearing temperature, substrate condition, light intensity, and flow rate) interact to enhance post-settlement survival and growth of sexually propagated juvenile Montipora capitata. Larvae were reared at 3 temperatures (high: 28.9°C, ambient: 27.2°C, low: 24.5°C) for 72 h during larval development, and were subsequently settled on aragonite plugs conditioned in seawater (1 or 10 wk) and raised in different light and flow regimes. These juvenile corals underwent a natural bleaching event in Kāne‘ohe Bay, O‘ahu, Hawai‘i (USA), in summer 2019, allowing us to opportunistically measure bleaching response in addition to survivorship and growth. This study demonstrates how leveraging light and flow can increase the survivorship and growth of juvenile M. capitata. In contrast, larval preconditioning and substrate conditioning had little overall effect on survivorship, growth, or bleaching response. Importantly, there was no optimal combination of abiotic conditions that maximized survival and growth in addition to bleaching tolerances. This study highlights the ability to tailor sexual reproduction for specific restoration goals by addressing knowledge gaps and incorporating practices that could improve resilience in propagated stocks.

Characterizing the impact of recovering sea otters on commercially important crabs in California estuaries

2020 ◽  
Vol 655 ◽  
pp. 123-137
Author(s):  
TM Grimes ◽  
MT Tinker ◽  
BB Hughes ◽  
KE Boyer ◽  
L Needles ◽  
...  
Keyword(s):  
Abiotic Factors ◽  
Sea Otter ◽  
Dungeness Crab ◽  
Sea Otters ◽  
Elkhorn Slough ◽  
Enhydra Lutris Nereis ◽  
Crab Abundance ◽  
Population Sizes ◽  
Commercially Important ◽  
The Impact

Protective legislation and management have led to an increase in California’s sea otter Enhydra lutris nereis population. While sea otter recovery has been linked to ecosystem benefits, sea otter predation may negatively affect commercially valuable species. Understanding the potential influence of sea otters is of particular importance as their range expands into estuaries that function as nurseries for commercially valuable species like Dungeness crab Metacarcinus magister. We consider how sea otter predation has affected the abundance and size of juvenile Dungeness crab in Elkhorn Slough, California, USA, and analyzed cancrid crab abundance and size across 4 California estuaries with and without sea otters to understand how biotic and abiotic factors contribute to observed variation in crab size and abundance. We compared trends in southern sea otters relative to Dungeness crab landings in California to assess whether increasing sea otter abundance have negatively impacted landings. In Elkhorn Slough, juvenile Dungeness crab abundance and size have declined since 2012, coinciding with sea otter population growth. However, the impact of sea otters on juvenile Dungeness crab size was habitat-specific and only significant in unvegetated habitat. Across estuaries, we found that cancrid crab abundance and size were negatively associated with sea otter presence. While abiotic factors varied among estuaries, these factors explained little of the observed variation in crab abundance or size. Although we found evidence that sea otters can have localized effects on cancrid crab populations within estuaries, we found no evidence that southern sea otters, at recent population sizes, have negatively impacted Dungeness crab landings in California from 2000-2014.

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