scholarly journals Habitat fragmentation causes coevolutionary burning spots

2017 ◽  
Author(s):  
H. De Kort ◽  
M. Baguette ◽  
J.G Prunier ◽  
M. Tessier ◽  
J. Monsimet ◽  
...  
Keyword(s):  
Habitat Fragmentation ◽  
Extinction Risk ◽  
Natural Community ◽  
Natural Conditions ◽  
Community Network ◽  
Community Functioning ◽  
Conservation Concern ◽  
Sustainable Conservation ◽  
Natural Settings ◽  
Natural Communities

AbstractHabitat fragmentation increasingly threatens the services provided by natural communities and ecosystem worldwide. An understanding of the underlying eco-evolutionary processes in natural settings is lacking, yet critical to realistic and sustainable conservation. Through integrating the multivariate genetic, biotic and abiotic facets of a natural community network experiencing various degrees of habitat fragmentation, we provide unique insights into the processes underlying community functioning in real, natural conditions. The focal community network comprises a parasitic butterfly of conservation concern, and its two obligatory host species, a plant and an ant. We show that fragmentation of butterfly habitat has the potential to impair the balance between dispersal and coevolution. This process can cause coevolutionary burning spots of decreased genetic diversity and therefore of increased extinction risk. We stress that ignoring such eco-evolutionary feed-backs inherent to the very functioning of natural communities can strongly impact their persistence.One Sentence Summary:Communities under threat of habitat fragmentation suffer increased extinction risk through coevolutionary overheating.

Complex environments alter competitive dynamics in fungi

2021 ◽  
Author(s):  
Justin Chan ◽  
Stephen Bonser ◽  
Michael M. Kasumovic ◽  
Jeff Powell ◽  
William Kirkham Cornwell
Keyword(s):  
Interspecific Interactions ◽  
Fungal Species ◽  
Wood Block ◽  
Complex Environments ◽  
Biotic Factor ◽  
Pairwise Interactions ◽  
Agar Media ◽  
Contextual Environment ◽  
Natural Settings ◽  
Natural Communities

Competition is a key biotic factor that often structures natural communities. Many attempts to disentangle how competition shapes natural communities have relied on experiments on simplified systems or through simple mathematical models. But these simplified approaches are limited in their ability to represent the complexity seen in more natural settings. Here, we considered the competitive pairwise dynamics between four saprotrophic fungal species. We tested whether the contextual environment changed these dynamics, repeating competitive experiments in a simple agar media and a more ecologically realistic wood block setting. We found that the competitive outcomes on agar media differed from those within the wood blocks. While superior competitors were identified across all pairwise interactions on agar, within the wood blocks, two of six interactions resulted in deadlock, where neither competitor could breach territory of the other, and one interaction resulted in a reversed competitive outcome. These results suggest that the complexity within natural substrates can alter the strength of interspecific interactions and may contribute to coexistence and the resulting high diversity of fungi often observed within wood.

scholarly journals Conservation evidence from climate-related stressors in the deep-time marine fossil record

2019 ◽  
Vol 374 (1788) ◽  
pp. 20190223 ◽  
Author(s):  
Matthew E. Clapham
Keyword(s):  
Global Change ◽  
Fossil Record ◽  
Extinction Risk ◽  
Marine Species ◽  
Activity Levels ◽  
Deep Time ◽  
Geographical Patterns ◽  
Time Record ◽  
Uncertain Future ◽  
Natural Settings

Conservation of marine species requires the ability to predict the effects of climate-related stressors in an uncertain future. Experiments and observations in modern settings provide crucial information, but lack temporal scale and cannot anticipate emergent effects during ongoing global change. By contrast, the deep-time fossil record contains the long-term perspective at multiple global change events that can be used, at a broad scale, to test hypothesized effects of climate-related stressors. For example, geologically rapid carbon cycle disruption has often caused crises in reef ecosystems, and selective extinctions support the hypothesis that greater activity levels promote survival. Geographical patterns of extinction and extirpation were more variable than predicted from modern physiology, with tropical and temperate extinction peaks observed at different ancient events. Like any data source, the deep-time record has limitations but also provides opportunities that complement the limitations of modern and historical data. In particular, the deep-time record is the best source of information on actual outcomes of climate-related stressors in natural settings and over evolutionary timescales. Closer integration of modern and deep-time evidence can expand the types of hypotheses testable with the fossil record, yielding better predictions of extinction risk as climate-related stressors continue to intensify in future oceans. This article is part of a discussion meeting issue ‘The past is a foreign country: how much can the fossil record actually inform conservation?’

scholarly journals Revisiting the impacts of non-random extinction on the tree-of-life

2013 ◽  
Vol 9 (4) ◽  
pp. 20130343 ◽  
Author(s):  
T. Jonathan Davies ◽  
Kowiyou Yessoufou
Keyword(s):  
Empirical Data ◽  
Extinction Risk ◽  
Tree Of Life ◽  
Branch Lengths ◽  
Recent Debate ◽  
Conservation Concern ◽  
Living Organisms ◽  
Close Relatives ◽  
The Impact ◽  
Number Of Branches

The tree-of-life represents the diversity of living organisms. Species extinction and the concomitant loss of branches from the tree-of-life is therefore a major conservation concern. There is increasing evidence indicating that extinction is phylogenetically non-random, such that if one species is vulnerable to extinction so too are its close relatives. However, the impact of non-random extinctions on the tree-of-life has been a matter of recent debate. Here, we combine simulations with empirical data on extinction risk in mammals. We demonstrate that phylogenetically clustered extinction leads to a disproportionate loss of branches from the tree-of-life, but that the loss of their summed lengths is indistinguishable from random extinction. We argue that under a speciational model of evolution, the number of branches lost might be of equal or greater consequences than the loss of summed branch lengths. We therefore suggest that the impact of non-random extinction on the tree-of-life may have been underestimated.

scholarly journals Quantification of habitat fragmentation reveals extinction risk in terrestrial mammals

2017 ◽  
Vol 114 (29) ◽  
pp. 7635-7640 ◽  
Author(s):  
Kevin R. Crooks ◽  
Christopher L. Burdett ◽  
David M. Theobald ◽  
Sarah R. B. King ◽  
Moreno Di Marco ◽  
...  
Keyword(s):  
Habitat Fragmentation ◽  
Extinction Risk ◽  
Threat Assessment ◽  
Risk Assessments ◽  
Phylogenetic Comparative Methods ◽  
Terrestrial Mammals ◽  
Geographic Range Size ◽  
Mammal Conservation ◽  
Primary Driver ◽  
Animal Taxon

Although habitat fragmentation is often assumed to be a primary driver of extinction, global patterns of fragmentation and its relationship to extinction risk have not been consistently quantified for any major animal taxon. We developed high-resolution habitat fragmentation models and used phylogenetic comparative methods to quantify the effects of habitat fragmentation on the world’s terrestrial mammals, including 4,018 species across 26 taxonomic Orders. Results demonstrate that species with more fragmentation are at greater risk of extinction, even after accounting for the effects of key macroecological predictors, such as body size and geographic range size. Species with higher fragmentation had smaller ranges and a lower proportion of high-suitability habitat within their range, and most high-suitability habitat occurred outside of protected areas, further elevating extinction risk. Our models provide a quantitative evaluation of extinction risk assessments for species, allow for identification of emerging threats in species not classified as threatened, and provide maps of global hotspots of fragmentation for the world’s terrestrial mammals. Quantification of habitat fragmentation will help guide threat assessment and strategic priorities for global mammal conservation.

scholarly journals Human urine as a source of nutrients for maize and its impacts on soil quality at Arba Minch, Ethiopia

2018 ◽  
Vol 8 (4) ◽  
pp. 516-521 ◽  
Author(s):  
Kinfe Kassa ◽  
Yesuf Ali ◽  
Wubishet Zewdie
Keyword(s):  
Human Urine ◽  
Chemical Properties ◽  
Application Rate ◽  
Ammonium Nitrogen ◽  
Natural Conditions ◽  
Treated Soil ◽  
Urine Diversion ◽  
Significant Difference ◽  
Natural Settings ◽  
And Control

Abstract A pot experiment was conducted at Arba Minch, Ethiopia to study the effects of urine on soil properties and yield of maize in natural settings. The pot treatments consisted of 500, 800, 1,000 and 1,200 ml of neat human urine collected from a UDDT (Urine Diversion Dry Toilet) added at different portions and control. The results showed that the response of the maize for most of the variables was very well expressed or significantly different at the application rate of 500 ml of urine; however, there was no significant difference between the 500 ml and the rest of the application. A significant increase in height, diameter, and length of leaf of maize was found in the urine treated soils. An improvement in soil phosphate chemical properties was noticed with increasing addition of urine; however, there was no significant increase in the ammonium nitrogen content and pH. The salinity of treated soil significantly increased at the bottom of the pot when compared with the control. In order to limit the increase in salinity of the soil and to get optimum maize growth in natural conditions, 500 ml urine addition per maize is recommended. The findings encourage the use of urine as fertilizer and a possible sink for UDDT waste.

scholarly journals An analytical model assessing the potential threat to natural habitats from insect resistance transgenes: continuous transgene input

2006 ◽  
Vol 2 (2) ◽  
pp. 293-297 ◽  
Author(s):  
Colleen K Kelly ◽  
Michael Bowler ◽  
Felix Breden
Keyword(s):  
Analytical Model ◽  
Insect Resistance ◽  
Relative Abundance ◽  
Model Output ◽  
Natural Community ◽  
Potential Threat ◽  
Natural Habitats ◽  
Ecological Processes ◽  
Using Data ◽  
Natural Communities

The potential effects of ‘escape’ of genetically modified material (transgenes) into natural communities is a major concern in their use. These effects may be limited in the first instance by limiting the proportion of transgene-carrying plants in the natural community. We previously presented an analytical model of the ecological processes governing the relative abundance and persistence of insect resistance (IR) transgenes in a natural community. In that paper, we illustrated the case in which the transgene is input into the community in a single season using data from oilseed rape (OSR) and its known herbivore, Plutella macropennis . We found that the transgene is unlikely to have a great impact on the natural community. Here, we extend the model for repeated input of crop pollen carrying the transgene. We show the model output, again using OSR, for continuous input of the transgene over 10 years, the projected commercial lifetime of a transgene without associated undesirable agronomic effects. Our results do not change our original conclusion that the IR transgene need not have a large impact on the natural community and our suggestions for assessing and mitigating any threat still stand.

scholarly journals Past, present, future: tracking and simulating genetic differentiation over time in a closed metapopulation system

2021 ◽  
Author(s):  
Florian Kunz ◽  
Annette Kohnen ◽  
Ursula Nopp-Mayr ◽  
Joy Coppes
Keyword(s):  
Genetic Differentiation ◽  
Extinction Risk ◽  
Recent Time ◽  
Conservation Strategies ◽  
Tetrao Urogallus ◽  
Migration Rates ◽  
Time Period ◽  
Conservation Concern ◽  
Set Up ◽  
Over Time

AbstractGenetic differentiation plays an essential role in the assessment of metapopulation systems of conservation concern. Migration rates affect the degree of genetic differentiation between subpopulations, with increasing genetic differentiation leading to increasing extinction risk. Analyses of genetic differentiation repeated over time together with projections into the future are therefore important to inform conservation. We investigated genetic differentiation in a closed metapopulation system of an obligate forest grouse, the Western capercaillieTetrao urogallus, by comparing microsatellite population structure between a historic and a recent time period. We found an increase in genetic differentiation over a period of approximately 15 years. Making use of forward simulations accounting for population dynamics and genetics from both time periods, we explored future genetic differentiation by implementing scenarios of differing migration rates. Using migration rates derived from the recent dataset, simulations predicted further increase of genetic differentiation by 2050. We then examined effects of two realistic yet hypothetical migration scenarios on genetic differentiation. While isolation of a subpopulation led to overall increased genetic differentiation, the re-establishment of connectivity between two subpopulations maintained genetic differentiation at recent levels. Our results emphasize the importance of maintaining connectivity between subpopulations in order to prevent further genetic differentiation and loss of genetic variation. The simulation set-up we developed is highly adaptable and will aid researchers and conservationists alike in anticipating consequences of conservation strategies for metapopulation systems.

scholarly journals ZAMIA (ZAMIACEAE) PHENOLOGY IN A PHYLOGENETIC CONTEXT: DOES IN SITU REPRODUCTIVE TIMING CORRELATE WITH ANCESTRY?

2016 ◽  
Vol 73 (3) ◽  
pp. 345-370 ◽  
Author(s):  
J. A. R. Clugston ◽  
M. P. Griffith ◽  
G. J. Kenicer ◽  
C. E. Husby ◽  
M. A. Calonje ◽  
...  
Keyword(s):  
Sequence Data ◽  
Extinction Risk ◽  
Central American ◽  
Reproductive Phenology ◽  
Herbarium Specimens ◽  
South American ◽  
Phenological Data ◽  
Seed Collection ◽  
Conservation Concern ◽  
American Clade

The Cycadales are a group of significant global conservation concern and have the highest extinction risk of all seed plants. Understanding the synchronisation of reproductive phenology of Cycadales may be useful for conservation by enabling the targeting of pollen and seed collection from wild populations and identifying the window of fertilisation to aid in the cultivation of Cycadales. Phenological data for 11 species of Zamia were gathered from herbarium specimens. Four phenological characters were coded with monthly character states. DNA was isolated and sequenced for 26S, CAB, NEEDLY, matK and rbcL, and a simultaneous phylogenetic analysis of phenology and DNA sequence data was carried out. Three major clades were recovered: a Caribbean clade, a Central American clade and a South American clade. Eight species showed statistically significant synchronisation in microsporangiate and ovulate phenological phases, indicating the time of fertilisation. Close reproductive synchronisation was consistently observed throughout the Caribbean clade (statistically significant in four of five species) but was less consistent in the Central American clade (statistically significant in one of two species) and South American clade (statistically significant in three of four species). Ultimately, phenology is shown to be a potential driver of speciation in some clades of Zamia and in others to be a potential barrier to hybridisation.

scholarly journals No evidence for a loss of genetic diversity despite a strong decline in size of a European population of the Corncrake Crex crex

2019 ◽  
Vol 30 (2) ◽  
pp. 260-266
Author(s):  
YOAN FOURCADE ◽  
DAVID S RICHARDSON ◽  
JEAN SECONDI
Keyword(s):  
Genetic Diversity ◽  
Extinction Risk ◽  
Bird Species ◽  
European Population ◽  
Grassland Bird ◽  
Low Genetic Diversity ◽  
Conservation Actions ◽  
Constant Gene ◽  
High Conservation ◽  
Conservation Concern

SummaryThe preservation of genetic diversity is an important aspect of conservation biology. Low genetic diversity within a population can lead to inbreeding depression and a reduction in adaptive potential, which may increase extinction risk. Here we report changes in genetic diversity over 12 years in a declining population of the Corncrake Crex crex, a grassland bird species of high conservation concern throughout Europe. Despite a twofold demographic decline during the same period, we found no evidence for a reduction of genetic diversity. The gradual genetic differentiation observed among populations of Corncrake across Europe suggests that genetic diversity is maintained in western populations by constant gene flow from the larger and more productive populations in eastern Europe and Asia. The maintenance of genetic diversity in this species is an opportunity that may help the implementation of effective conservation actions across the Corncrake’s European range.

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