The Colonization and Formation of Equilibrium Plant Species Associations on Badger Disturbances in a Tall‐Grass Prairie

1975 ◽  
Vol 45 (3) ◽  
pp. 285-305 ◽  
Author(s):  
William J. Platt
2021 ◽  
Author(s):  
◽  
Justis Henault ◽  

The Poweshiek skipperling (Oarisma poweshiek) is endemic to the tall grass prairie in North America, and is now critically endangered globally. Existing populations are scattered amongst tall grass prairie remnants. However, the host food plants eaten by Poweshiek skipperling larvae, the vegetative and microclimatic descriptions of immature and adult microhabitats as well as O. poweshiek behaviour in Manitoba are unknown. I observed the foraging behaviour of larval O. poweshiek in natural habitat to determine the plant species that they consume and document their development. I also followed adults in prairie patches to identify locations in which various activities, such as egg laying or nectar feeding, were facilitated by the habitat. I measured vegetative, structural and microclimatic attributes of microhabitats to determine potential characteristics which facilitate various adult activities and larval development. Larvae appeared to navigate microhabitats to locate host food plant species, alternating between shoots of various species throughout their development. Adults flew almost exclusively in the prairie plant community, rarely flew in shrub or ephemeral wetland communities and were never observed flying in wetland or forest communities. Adult activities appeared to be distributed along a soil moisture gradient, with egg laying associated with the mesic section of the moisture gradient, resting and/or basking associated with the drier section and nectar feeding generally associated with sections throughout the moisture gradient. My research contributes knowledge about larval O. poweshiek foraging and adult habitat interactions in prairies in Manitoba, Canada. Discoveries from my research may guide habitat stewardship to ensure that high quality habitat is available for every life stage and inform reintroduction activities to ensure potential release locations contain required habitat features. Novel descriptions of locations which facilitate larval development and various adult activities may inform provincial and federal recovery strategies to increase the chances of O. poweshiek’s survival. My findings may also initiate further research about the Poweshiek skippering and possibly guide the strategies to recover other Lepidopterans-at-risk. Now with a greater understanding of larval foraging and adult interactions, we may hopefully generate potential causes which explain O. poweshiek’s decline and identify possible solutions to facilitate its successful recovery!


2019 ◽  
Author(s):  
Krishna Anujan ◽  
Sebastian A. Heilpern ◽  
Case M. Prager ◽  
Shahid Naeem

AbstractHigher levels of diversity within trophic levels are necessary to sustain multiple ecosystem functions, but this diversity-multifunctionality relationship peaks at intermediate percent-function thresholds. The presence of multiple trophic levels, or trophic complexity, affects ecosystem multifunctionality but its effect on the diversity-multifunctionality relationship has not been experimentally tested. To test the sensitivity of the diversity-multifunctionality relationship to trophic complexity, we simultaneously manipulated plant diversity and trophic complexity in a multifactorial tall-grass prairie mesocosm experiment at Cedar Creek, Minnesota, USA. Trophic complexity altered the diversity-multifunctionality relationship, by lowering the height of the peak as well as by shifting to a negative effect at lower thresholds. These outcomes are consistent with decreases in both the “jack-of-all-trades” effect and complementarity among plant species. Our findings suggest that trophic complexity, which is experiencing widespread declines on a global scale, is important for sustaining ecosystem multifunctionality in the face of equally widespread declines in biodiversity.


2021 ◽  
Vol 193 (2) ◽  
Author(s):  
Jens Oldeland ◽  
Rasmus Revermann ◽  
Jona Luther-Mosebach ◽  
Tillmann Buttschardt ◽  
Jan R. K. Lehmann

AbstractPlant species that negatively affect their environment by encroachment require constant management and monitoring through field surveys. Drones have been suggested to support field surveyors allowing more accurate mapping with just-in-time aerial imagery. Furthermore, object-based image analysis tools could increase the accuracy of species maps. However, only few studies compare species distribution maps resulting from traditional field surveys and object-based image analysis using drone imagery. We acquired drone imagery for a saltmarsh area (18 ha) on the Hallig Nordstrandischmoor (Germany) with patches of Elymus athericus, a tall grass which encroaches higher parts of saltmarshes. A field survey was conducted afterwards using the drone orthoimagery as a baseline. We used object-based image analysis (OBIA) to segment CIR imagery into polygons which were classified into eight land cover classes. Finally, we compared polygons of the field-based and OBIA-based maps visually and for location, area, and overlap before and after post-processing. OBIA-based classification yielded good results (kappa = 0.937) and agreed in general with the field-based maps (field = 6.29 ha, drone = 6.22 ha with E. athericus dominance). Post-processing revealed 0.31 ha of misclassified polygons, which were often related to water runnels or shadows, leaving 5.91 ha of E. athericus cover. Overlap of both polygon maps was only 70% resulting from many small patches identified where E. athericus was absent. In sum, drones can greatly support field surveys in monitoring of plant species by allowing for accurate species maps and just-in-time captured very-high-resolution imagery.


2007 ◽  
Vol 88 (9) ◽  
pp. 1369-1382 ◽  
Author(s):  
Craig B. Clements ◽  
Shiyuan Zhong ◽  
Scott Goodrick ◽  
Ju Li ◽  
Brian E. Potter ◽  
...  

Grass fires, although not as intense as forest fires, present a major threat to life and property during periods of drought in the Great Plains of the United States. Recently, major wildland grass fires in Texas burned nearly 1.6 million acres and destroyed over 730 homes and 1320 other buildings. The fires resulted in the death of 19 people, an estimated loss of 10,000 head of livestock, and more than $628 million in damage, making the 2005/06 fire season the worst on record for the state of Texas. As an aid to fire management, various models have been developed to describe fire behavior. However, these models strongly emphasize fuels and fail to adequately consider the role of convective dynamics within the atmosphere and its interaction with the fire due to the lack of observational data. To fill this gap, an intensive field measurement campaign called FireFlux was conducted during February 2006 near Houston, Texas. The campaign employed a variety of instrument platforms to collect turbulence data at multiple levels within and immediately downwind of a 155 acre tall-grass prairie burn unit. This paper presents some first-time observations of atmospheric turbulent structures/fluxes associated with intense grass fires and provides a basis to further our understanding of the dynamics of grass fires and their interactions with the atmosphere.


2019 ◽  
Vol 28 (4) ◽  
pp. 308 ◽  
Author(s):  
Craig B. Clements ◽  
Adam K. Kochanski ◽  
Daisuke Seto ◽  
Braniff Davis ◽  
Christopher Camacho ◽  
...  

The FireFlux II experiment was conducted in a tall grass prairie located in south-east Texas on 30 January 2013 under a regional burn ban and high fire danger conditions. The goal of the experiment was to better understand micrometeorological aspects of fire spread. The experimental design was guided by the use of a coupled fire–atmosphere model that predicted the fire spread in advance. Preliminary results show that after ignition, a surface pressure perturbation formed and strengthened as the fire front and plume developed, causing an increase in wind velocity at the fire front. The fire-induced winds advected hot combustion gases forward and downwind of the fire front that resulted in acceleration of air through the flame front. Overall, the experiment collected a large set of micrometeorological, air chemistry and fire behaviour data that may provide a comprehensive dataset for evaluating and testing coupled fire–atmosphere model systems.


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