scholarly journals Karst sinkholes as foci of biodiversity in the Hoosier National Forest

2020 ◽  
Vol 82 (4) ◽  
pp. 276-292
Author(s):  
Julien Lewis ◽  
Marc Milne ◽  
Charles Stephen ◽  
Daniel Dourson
Keyword(s):  
Species Richness ◽  
Plant Community ◽  
Deciduous Forest ◽  
Land Snails ◽  
Community Type ◽  
National Forest ◽  
Target Groups ◽  
Biological Communities ◽  
Plant Community Type ◽  
Hoosier National Forest

Sinkholes are a well-known, but poorly studied, aspect of karst environments. In 2015, the Hoosier National Forest in southern Indiana, USA, commissioned a study of sinkhole habitats to assess their ecological role. The ecosystems of 26 sinkholes were evaluated to determine if sinkhole floor biological communities and species richness were a function of the surrounding plant community. Each sinkhole was sampled four times for five target groups of invertebrates at intervals of approximately three months, for a total of 104 visits. The sampling resulted in finding 140 taxa, including 31 land snails, 14 millipedes, 3 terrestrial isopods, 83 spiders and 9 pseudoscorpions. Of exceptional note were at least 12 new state records and a probable new species of pseudoscorpion. Several of these species appear to be endemic to sinkhole habitats. A link was confirmed between species richness and the surrounding plant community, specifically that the highest biodiversity was found in sinkholes surrounded by native deciduous forest, followed by native glades. Sinkholes in fields from which deciduous forest had been removed possessed markedly decreased species diversity, as did non-native plantings of pines. Sinkhole habitats had a significantly higher species richness than adjacent non-sinkhole control sites. Moreover, the arthropod communities that were found in each sinkhole within each plant community type were different from each other and the surrounding non-sinkhole areas. These data suggest that sinkholes are more than just depressions in epigean landscapes, but possess unique invertebrate communities linked to the surrounding plant community.

Increased fire severity triggers positive feedbacks of greater vegetation flammability and favors plant community‐type conversions

2020 ◽  
Author(s):  
Jennifer Brenda Landesmann ◽  
Florencia Tiribelli ◽  
Juan Paritsis ◽  
Thomas Thorstein Veblen ◽  
Thomas Kitzberger
Keyword(s):  
Plant Community ◽  
Fire Severity ◽  
Community Type ◽  
Positive Feedbacks ◽  
Plant Community Type

scholarly journals Understory Vegetation Change Following Woodland Reduction Varies by Plant Community Type and Seeding Status: A Region-Wide Assessment of Ecological Benefits and Risks

Plants ◽  
2020 ◽  
Vol 9 (9) ◽  
pp. 1113
Author(s):  
Thomas A. Monaco ◽  
Kevin L. Gunnell
Keyword(s):  
Ecosystem Services ◽  
Plant Community ◽  
Vegetation Change ◽  
Perennial Grass ◽  
Understory Vegetation ◽  
Community Type ◽  
Ecological Benefits ◽  
Plant Community Type ◽  
Community Types ◽  
Woodland Encroachment

Woodland encroachment is a global issue linked to diminished ecosystem services, prompting the need for restoration efforts. However, restoration outcomes can be highly variable, making it difficult to interpret the ecological benefits and risks associated with woodland-reduction treatments within semiarid ecosystems. We addressed this uncertainty by assessing the magnitude and direction of vegetation change over a 15-year period at 129 sagebrush (Artemisia spp.) sites following pinyon (Pinus spp.) and juniper (Juniperus spp.) (P–J) reduction. Pretreatment vegetation indicated strong negative relationships between P–J cover and the abundance of understory plants (i.e., perennial grass and sagebrush cover) in most situations and all three components differed significantly among planned treatment types. Thus, to avoid confounding pretreatment vegetation and treatment type, we quantified overall treatment effects and tested whether distinct response patterns would be present among three dominant plant community types that vary in edaphic properties and occur within distinct temperature/precipitation regimes using meta-analysis (effect size = lnRR = ln[posttreatment cover/pretreatment cover]). We also quantified how restoration seedings contributed to overall changes in key understory vegetation components. Meta-analyses indicated that while P–J reduction caused significant positive overall effects on all shrub and herbaceous components (including invasive cheatgrass [Bromus tectorum] and exotic annual forbs), responses were contingent on treatment- and plant community-type combinations. Restoration seedings also had strong positive effects on understory vegetation by augmenting changes in perennial grass and perennial forb components, which similarly varied by plant community type. Collectively, our results identified specific situations where broad-scale efforts to reverse woodland encroachment substantially met short-term management goals of restoring valuable ecosystem services and where P–J reduction disposed certain plant community types to ecological risks, such as increasing the probability of native species displacement and stimulating an annual grass-fire cycle. Resource managers should carefully weigh these benefits and risks and incorporate additional, appropriate treatments and/or conservation measures for the unique preconditions of a given plant community in order to minimize exotic species responses and/or enhance desirable outcomes.

scholarly journals Effect of environmental gradients on diversity and plant community distribution in remnant dry Afromontane forest of Mount Duro, Nagelle Arsi, Ethiopia

2020 ◽  
Vol 58 (1) ◽  
pp. 21-31
Author(s):  
Mengistu Teshome ◽  
Zebene Asfaw ◽  
Gemedo Dalle
Keyword(s):  
Species Richness ◽  
Species Diversity ◽  
Plant Species ◽  
Plant Community ◽  
Plant Communities ◽  
Forest Ecosystem ◽  
Environmental Variables ◽  
Community Type ◽  
Diversity Assessment ◽  
Bersama Abyssinica

Abstract For forest ecosystem management to be effective, explicit understanding of the species diversity-environmental relationship along elevation gradient is crucial. This study aimed at identifying and describing plant communities and also documenting their species diversity. Evaluation of relationships between selected environmental variables and species diversity was another objective of this study. Systematic sampling techniques were used to collect vegetation data in a total of forty two sample plots (size=20×20 m). Within main plots, four sub-plots of 5×5 m were established at four corners and – one sub-plot of the same size in the center. These plots were used for shrub and herb diversity assessment. Within each sample plot, all plant species were documented and their scientific names were identified. Environmental variables, such as: elevation, aspect and slope, were also recorded for each main plot. Species diversity was determined using Shannon-Wiener diversity index and evenness in R statistical software. Agglomerative hierarchical clustering method was used for plant community classification. The total of 44 plant species belonging to 30 families was documented. Four plant community types were identified with different diversity, evenness and species richness. These plant communities were: Afrocurpus falcatus-Ficus sur, Maesa lanceolata-Bersama abyssinica, Vernonia myriantha-Urera hypselodendron and Croton machrostachus-Tecleanobilis occurring at average elevation of 2521, 2429, 2329, and 2364 m asl, respectively. Maesa lanceolata-Bersama abyssinica community type exhibited the highest species diversity and evenness followed by Croton machrostachus-Teclea nobilis community type showing the fact that median elevation ranges were rich in species. Elevation and slope gradient explained significant variation in species richness in the studied forest. For effective conservation of biodiversity and sustainable management of the forest ecosystem, further research on the impacts of anthropogenic disturbances and soil properties is recommended as a result of this study.

scholarly journals Gene flow between two thick-billed grasswren subspecies with low dispersal creates a genomic pattern of isolation-by-distance

2021 ◽  
Author(s):  
Amy Lee Slender ◽  
Marina Louter ◽  
Steven A Myers ◽  
Tessa Bradford ◽  
Michael G Gardner ◽  
...  
Keyword(s):  
Gene Flow ◽  
Environmental Change ◽  
Plant Community ◽  
Isolation By Distance ◽  
Genotyping By Sequencing ◽  
Community Type ◽  
Adaptive Potential ◽  
Plant Community Type ◽  
Genomic Markers ◽  
Community Types

Context In the era of the Anthropocene, habitat loss and environmental change threaten the persistence of many species. Genotyping-By-Sequencing (GBS) is a useful molecular tool for understanding how patterns of gene flow are associated with contemporary habitat distributions that may be affected by environmental change. Two parapatric subspecies of the threatened thick-billed grasswren (TBGW; Amytornis modestus) more frequently occur in different plant communities. As such, a preference for plant community type could reduce subspecific introgression and increase genetic diversity at the parapatric boundary. Aims We aimed to measure gene flow within and among two TBGW subspecies and tested whether divergent genomic markers were associated with plant community type. Methods We sequenced 118 individuals from either of the two TBGW subspecies or in the region of parapatry and identified 7583 SNPs through ddRADseq. Key results We found evidence of asymmetric gene flow and a genomic pattern of isolation-by-distance. There were sixteen genomic outliers correlated with plant community type (regardless of location). Conclusions These findings show that plant community type does not prevent introgression in one subspecies (A. m. raglessi), but low dispersal and habitat heterogeneity could contribute to the maintenance of distinct subspecific morphotypes. Local adaptation in different plant community types could also provide a mechanism for future divergence. Implications We suggest subspecific introgression could increase genetic variation and the adaptive potential of the species, facilitating species persistence under conditions of climate change.

Plant community type and small-scale disturbances, but not altitude, influence the invasibility in subarctic ecosystems

2012 ◽  
Vol 197 (3) ◽  
pp. 1002-1011 ◽  
Author(s):  
Ann Milbau ◽  
Anna Shevtsova ◽  
Nora Osler ◽  
Maria Mooshammer ◽  
Bente J. Graae
Keyword(s):  
Plant Community ◽  
Community Type ◽  
Small Scale ◽  
Plant Community Type ◽  
Subarctic Ecosystems
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