Assessing long-term risks of prairie seed harvest: what is the role of life-history?

Botany ◽  
2017 ◽  
Vol 95 (11) ◽  
pp. 1081-1092 ◽  
Author(s):  
Justin C. Meissen ◽  
Susan M. Galatowitsch ◽  
Meredith W. Cornett
Keyword(s):  
Tallgrass Prairie ◽  
High Intensity ◽  
Reproductive Strategies ◽  
Extinction Risk ◽  
Native Plant ◽  
Seed Harvest ◽  
Prairie Restorations ◽  
Clonal Species

To meet the demand for more and larger tallgrass prairie restorations, seed is frequently collected en-masse from remnant native plant populations. Overharvesting of seed may lead to population extinctions, but these risks are not well studied. Species’ reproductive strategies may provide a basis for risk assessment. We assessed extinction risks associated with seed harvest for grassland plant species with different reproductive strategies (clonal vs. non-clonal). Using stage-based matrix models, we projected the extinction risk for two clonal and four non-clonal prairie species subjected to five harvest scenarios: (i) no harvest, (ii and iii) annual harvest at low/high intensity (50% and 75% seeds removed), and (iv and v) triennial harvest at low/high intensity. We compared the magnitude of growth or decline (λ) and mean extinction risk among populations during a 25-year modeling period. Non-clonal species were robust to triennial and low-intensity harvest, but susceptible to decreases in population growth (λ) up to 0.5 and elevated extinction risks up to 95% with high intensity annual harvest. Clonal species were unaffected by seed harvest, owing to a compensatory effect of vegetative propagation on growth rates. To maintain populations of non-clonal species in remnant grasslands, high intensity annual harvest should be avoided.

scholarly journals Adding fossil occupancy trajectories to the assessment of modern extinction risk

2016 ◽  
Vol 12 (10) ◽  
pp. 20150813 ◽  
Author(s):  
Wolfgang Kiessling ◽  
Ádám T. Kocsis
Keyword(s):  
Fossil Record ◽  
Extinction Risk ◽  
Strong Predictor ◽  
Marine Species ◽  
Species Traits ◽  
Latent Extinction ◽  
Extant Species ◽  
Temporal Trajectory

Besides helping to identify species traits that are commonly linked to extinction risk, the fossil record may also be directly relevant for assessing the extinction risk of extant species. Standing geographical distribution or occupancy is a strong predictor of both recent and past extinction risk, but the role of changes in occupancy is less widely assessed. Here we demonstrate, based on the Cenozoic fossil record of marine species, that both occupancy and its temporal trajectory are significant determinants of risk. Based on extinct species we develop a model on the additive and interacting effects of occupancy and its temporal changes on extinction risk. We use this model to predict extinction risk of extant species. The predictions suggest a moderate risk for marine species on average. However, some species seem to be on a long-term decline and potentially at a latent extinction risk, which is not considered in current risk assessments.

scholarly journals Effects of Fire and Large Herbivores on Canopy Nitrogen in a Tallgrass Prairie

2019 ◽  
Vol 11 (11) ◽  
pp. 1364 ◽  
Author(s):  
Bohua Ling ◽  
Edward J. Raynor ◽  
Douglas G. Goodin ◽  
Anthony Joern
Keyword(s):  
Spatial Variability ◽  
Nitrogen Content ◽  
Tallgrass Prairie ◽  
High Nitrogen Content ◽  
High Nitrogen ◽  
Grazing History ◽  
One Year ◽  
Canopy Nitrogen

This study analyzed the spatial heterogeneity of grassland canopy nitrogen in a tallgrass prairie with different treatments of fire and ungulate grazing (long-term bison grazing vs. recent cattle grazing). Variogram analysis was applied to continuous remotely sensed canopy nitrogen images to examine the spatial variability in grassland canopies. Heterogeneity metrics (e.g., the interspersion/juxtaposition index) were calculated from the categorical canopy nitrogen maps and compared among fire and grazing treatments. Results showed that watersheds burned within one year had higher canopy nitrogen content and lower interspersions of high-nitrogen content patches than watersheds with longer fire intervals, suggesting an immediate and transient fire effect on grassland vegetation. In watersheds burned within one year, high-intensity grazing reduced vegetation density, but promoted grassland heterogeneity, as indicated by lower canopy nitrogen concentrations and greater interspersions of high-nitrogen content patches at the grazed sites than at the ungrazed sites. Variogram analyses across watersheds with different grazing histories showed that long-term bison grazing created greater spatial variability of canopy nitrogen than recent grazing by cattle. This comparison between bison and cattle is novel, as few field experiments have evaluated the role of grazing history in driving grassland heterogeneity. Our analyses extend previous research of effects from pyric herbivory on grassland heterogeneity by highlighting the role of grazing history in modulating the spatial and temporal distribution of aboveground nitrogen content in tallgrass prairie vegetation using a remote sensing approach. The comparison of canopy nitrogen properties and the variogram analysis of canopy nitrogen distribution provided by our study are useful for further mapping grassland canopy features and modeling grassland dynamics involving interplays among fire, large grazers, and vegetation communities.

scholarly journals Tallgrass Prairie Responses to Management Practices and Disturbances: A Review

Agronomy ◽  
2018 ◽  
Vol 8 (12) ◽  
pp. 300 ◽  
Author(s):  
Pradeep Wagle ◽  
Prasanna Gowda
Keyword(s):  
Species Richness ◽  
Soil Quality ◽  
Plant Species ◽  
Tallgrass Prairie ◽  
Management Practices ◽  
The United States ◽  
N Fertilization ◽  
Native Plant ◽  
The Impact

Adoption of better management practices is crucial to lessen the impact of anthropogenic disturbances on tallgrass prairie systems that contribute heavily for livestock production in several states of the United States. This article reviews the impacts of different common management practices and disturbances (e.g., fertilization, grazing, burning) and tallgrass prairie restoration on plant growth and development, plant species composition, water and nutrient cycles, and microbial activities in tallgrass prairie. Although nitrogen (N) fertilization increases aboveground productivity of prairie systems, several factors greatly influence the range of stimulation across sites. For example, response to N fertilization was more evident on frequently or annually burnt sites (N limiting) than infrequently burnt and unburnt sites (light limiting). Frequent burning increased density of C4 grasses and decreased plant species richness and diversity, while plant diversity was maximized under infrequent burning and grazing. Grazing increased diversity and richness of native plant species by reducing aboveground biomass of dominant grasses and increasing light availability for other species. Restored prairies showed lower levels of species richness and soil quality compared to native remnants. Infrequent burning, regular grazing, and additional inputs can promote species richness and soil quality in restored prairies. However, this literature review indicated that all prairie systems might not show similar responses to treatments as the response might be influenced by another treatment, timing of treatments, and duration of treatments (i.e., short-term vs. long-term). Thus, it is necessary to examine the long-term responses of tallgrass prairie systems to main and interacting effects of combination of management practices under diverse plant community and climatic conditions for a holistic assessment.

Reproductive Behavior in the Human Male

2019 ◽  
pp. 123-141
Author(s):  
Stefan M. M. Goetz ◽  
Glenn Weisfeld ◽  
Samuele Zilioli
Keyword(s):  
Reproductive Strategies ◽  
Life History Theory ◽  
Parental Effort ◽  
Evolutionary Time ◽  
Short Term ◽  
Physical Conditions ◽  
Human Male ◽  
Evolutionary Success

Given the pivotal role of differential reproduction to the evolutionary success of ancestral men, evolution has produced a plethora of reproductive strategies aimed at solving the complexities of intramale competition and satisfying and/or thwarting the reproductive desires of women. Life history theory recognizes that an organism has limited resources and must invest energy appropriately. Broadly, reproductive strategies can be dichotomized into short-term (emphasizing mating over parental effort) versus long-term (emphasizing parenting over mating effort) strategies. Increasingly, the neuroendocrine system—especially testosterone—has been recognized as the proximate mechanism orchestrating adoption of one strategy over the other. This chapter reviews behaviors geared toward solving problems associated with both long-term and short-term reproductive strategies and discusses the neuroendocrine correlates. The adoption of one strategy over another is conceptualized as conditional or facultative adaptations in which strategic switching points are tuned over evolutionary time to produce optimal fitness responses to men’s social and physical conditions.

scholarly journals Understanding modern extinctions in marine ecosystems: the role of palaeoecological data

2016 ◽  
Vol 12 (4) ◽  
pp. 20150951 ◽  
Author(s):  
Matthew A. Kosnik ◽  
Michał Kowalewski
Keyword(s):  
Anthropogenic Impacts ◽  
Extinction Risk ◽  
Marine Ecosystems ◽  
Sedimentary Records ◽  
Proxy Records ◽  
Naturally Occurring ◽  
Manipulative Experiments ◽  
Anthropogenic Processes

Because anthropogenic impacts on ecological systems pre-date the oldest scientific observations, historical documents and archaeological records, understanding modern extinctions requires additional data sources that extend further back in time. Palaeoecological records, which provide quantitative proxy records of ecosystems prior to human impact, are essential for understanding recent extinctions and future extinction risks. Here we critically review the value of the most recent fossil record in contributing to our understanding of modern extinctions and illustrate through case studies how naturally occurring death assemblages and Holocene sedimentary records provide context to the plight of marine ecosystems. While palaeoecological data are inherently restricted censuses of past communities (manipulative experiments are not possible), they yield quantitative records over temporal scales that are beyond the reach of ecology. Only by including palaeoecological data is it possible to fully assess the role of long-term anthropogenic processes in driving modern extinction risk.

Effect of plastic mulching on the accumulation and distribution of macro and micro plastic particles in the soil - A case study of two farming systems in North West China

2020 ◽  
Author(s):  
Fanrong Meng
Keyword(s):  
High Intensity ◽  
Farming Systems ◽  
Northwest China ◽  
Farm Management ◽  
Plastic Films ◽  
North West ◽  
Plastic Mulching

<p>Plastic mulching is a common farming practice in arid and semi-arid regions. Inappropriate disposal of plastic films can lead to the contamination of macroplastics (MaPs) and microplastics (MiPs) in the soil. To study the effects of plastic mulching on the contamination of soil with MaPs and MiPs and the role of farm management on this contamination, research was done on two farming systems in Northwest China, where plastic mulching is intensively used. Farming in Wutong Village (S1) is characterized by small plots and low-intensity machinery tillage while farming in Shihezi (S2) is characterized by large plots and high-intensity machinery tillage. Soils were sampled to a depth of 30 cm and analysed. The results showed that MaPs ranged from 30.3 kg·ha<sup>-1</sup> to 82.3 kg·ha<sup>-1</sup> in S1 and from 43.5 kg·ha<sup>-1</sup> to 148 kg·ha<sup>-1</sup> in S2. The main macroplastics  size categories were 2-10 cm<sup>2</sup> and 10-50 cm<sup>2</sup> in S1 and  < 2 cm<sup>2</sup> and 2-10 cm<sup>2</sup> in S2. In S1, we found that 6-8 years of continuous mulching practice resulted in the accumulation of more MaPs as compared to the use of intermittent mulching over the span of 30 years. For S2,  6 to 15 years of plastic mulching use led to MaPs accumulation in fields but from 15 to18 years, the MaPs number and content in soils dropped due to further fragmentation of the plastic and its dispersal into the environment. MiPs were mainly detected in fields with > 30 years of mulching use in S1 and discovered in all fields in S2, this indicated that  long-term cultivation and high-intensity machinery tillage could lead to more severe microplastic pollution. These results emphasized the impacts of  farm management on the accumulation and spread of MaPs and MiPs in the soil and regulations are needed to prevent further contamination of the soil.</p>

scholarly journals Is High-Intensity Interval Training Suitable to Promote Neuroplasticity and Cognitive Functions after Stroke?

2021 ◽  
Vol 22 (6) ◽  
pp. 3003
Author(s):  
Nicolas Hugues ◽  
Christophe Pellegrino ◽  
Claudio Rivera ◽  
Eric Berton ◽  
Caroline Pin-Barre ◽  
...  
Keyword(s):  
Cognitive Functions ◽  
High Intensity ◽  
Interval Training ◽  
Stroke Severity ◽  
High Intensity Interval Training ◽  
Clinical Role ◽  
Cognitive Benefits ◽  
High Intensity Interval

Stroke-induced cognitive impairments affect the long-term quality of life. High-intensity interval training (HIIT) is now considered a promising strategy to enhance cognitive functions. This review is designed to examine the role of HIIT in promoting neuroplasticity processes and/or cognitive functions after stroke. The various methodological limitations related to the clinical relevance of studies on the exercise recommendations in individuals with stroke are first discussed. Then, the relevance of HIIT in improving neurotrophic factors expression, neurogenesis and synaptic plasticity is debated in both stroke and healthy individuals (humans and rodents). Moreover, HIIT may have a preventive role on stroke severity, as found in rodents. The potential role of HIIT in stroke rehabilitation is reinforced by findings showing its powerful neurogenic effect that might potentiate cognitive benefits induced by cognitive tasks. In addition, the clinical role of neuroplasticity observed in each hemisphere needs to be clarified by coupling more frequently to cellular/molecular measurements and behavioral testing.

Perched Peatlands: insights into eco-hydrologic roles of peatlands in water limited boreal environments

2020 ◽  
Author(s):  
Kevin J Devito ◽  
Lindsay M James ◽  
Daniel S Alessi ◽  
Kelly Hokanson ◽  
Nick Kettridge ◽  
...  
Keyword(s):  
Water Balance ◽  
High Intensity ◽  
Water Storage ◽  
Landscape Scale ◽  
Water Sources ◽  
Relative Role ◽  
Wetland Complex ◽  
Boreal Landscapes

<p>Peatlands are integral to sustaining landscape eco-hydrological function in water-limited boreal landscapes and serve as important water sources for headwater streams and surrounding forests, and recently for mega-scale watershed construction associated with resource extraction. Despite the regional moisture deficit of the Boreal plains, peatlands and margin swamps exist on topographic highs where low permeability (clogging) layers occur proximal to the surface and are apparently isolated from surface water and local and regional groundwater inputs. The <span>water generating mechanisms (</span>external water sources, internal feedback mechanisms) that<span> enable peatland formation with such </span>delicate water balances<span> in these </span>unique hydrogeologic settings are not well known, and have large implications for understanding the eco-hydrologic role of natural peatlands as well as direct peatland construction in drier boreal landscapes.</p><p>A multi-year sampling campaign was conducted to collect hydrometric, geochemical (DOC, pH, major cations and anions), and isotopic (D/H, <sup>18</sup>O/<sup>16</sup>O) data from a small isolated peatland-margin swamp complex. We explored the relative roles of margin swamps in buffering water loss and generating perched groundwater, shading and wind protection from adjacent forests, snow redistribution in and around the peatland, and wetland feedbacks on maintenance of peatland moisture and ecosystem function. Long-term (18 year) records of water table gradients between the peatland and an adjacent forest combined with 3 year high intensity <!-- Not sure if you mean to separate the long term data from the high intensity data from Lindsey’s project -->water balance calculations show the peatland to be a source of water to adjacent forests during this period and illustrate the dominance of autogenic wetland feedbacks over allogenic controls (external sources) in peatland development at this location. Contrasts in water storage due to the morphometry <!-- Morphometry? -->of the clogging layer appear to the dominant determinants of peatland and swamp form and function. Layers of decomposed peat and fine textured mineral soils in margin swamps with low water storage potential promoted frequent soil saturation and anoxia, limiting forest vegetation growth and water uptake, further enhancing wetland vegetation, water conservation and generation within the wetland complex. Shading and wind protection from adjacent forests appear to influence soil frost duration and atmospheric demand to further reduce evapotranspiration losses contributing to a slight moisture surplus in the wetland complex relative to the adjacent forest. Understanding the water balance and moisture surplus controls in isolated peatlands sheds light on the relative role of allogenic and autogenic controls on peatlands with implications for: 1) assessing regional eco-hydrological roles of peatland and forestland covers, 2) predicting landscape-scale response to environmental change and land use, and 3) directing landscape scale reclamation or large reconstruction projects over a range of geologic settings in water-limited boreal regions.</p>

scholarly journals High-intensity interval training-induced metabolic adaptation coupled with an increase in Hif-1α and glycolytic protein expression

2015 ◽  
Vol 119 (11) ◽  
pp. 1297-1302 ◽  
Author(s):  
Takaaki Abe ◽  
Yu Kitaoka ◽  
Dale Manjiro Kikuchi ◽  
Kohei Takeda ◽  
Osamu Numata ◽  
...  
Keyword(s):  
Skeletal Muscle ◽  
High Intensity ◽  
Interval Training ◽  
Metabolic Adaptation ◽  
Protein Levels ◽  
Expression Of Genes ◽  
High Intensity Interval ◽  
Gastrocnemius Muscles

It is known that repeated bouts of high-intensity interval training (HIIT) lead to enhanced levels of glycolysis, glycogenesis, and lactate transport proteins in skeletal muscle; however, little is known about the molecular mechanisms underlying these adaptations. To decipher the mechanism leading to improvement of skeletal muscle glycolytic capacity associated with HIIT, we examined the role of hypoxia-inducible factor-1α (Hif-1α), the major transcription factor regulating the expression of genes related to anaerobic metabolism, in the adaptation to HIIT. First, we induced Hif-1α accumulation using ethyl 3,4-dihydroxybenzoate (EDHB) to assess the potential role of Hif-1α in skeletal muscle. Treatment with EDHB significantly increased the protein levels of Hif-1α in gastrocnemius muscles, accompanied by elevated expression of genes related to glycolysis, glycogenesis, and lactate transport. Daily administration of EDHB for 1 wk resulted in elevated glycolytic enzyme activity in gastrocnemius muscles. Second, we examined whether a single bout of HIIT could induce Hif-1α protein accumulation and subsequent increase in the expression of genes related to anaerobic metabolism in skeletal muscle. We observed that the protein levels of Hif-1α and expression of the target genes were elevated 3 h after an acute bout of HIIT in gastrocnemius muscles. Last, we examined the effects of long-term HIIT. We found that long-term HIIT increased the basal levels of Hif-1α as well as the glycolytic capacity in gastrocnemius muscles. Our results suggest that Hif-1α is a key regulator in the metabolic adaptation to high-intensity training.

scholarly journals Fire history and weather interact to determine extent and synchrony of mast-seeding in rhizomatous scrub oaks of Florida

2021 ◽  
Vol 376 (1839) ◽  
Author(s):  
Mario B. Pesendorfer ◽  
Reed Bowman ◽  
Georg Gratzer ◽  
Shane Pruett ◽  
Angela Tringali ◽  
...  
Keyword(s):  
Seed Production ◽  
Reproductive Strategies ◽  
Fire History ◽  
Interactive Effects ◽  
Mast Seeding ◽  
Florida Scrub ◽  
Acorn Production ◽  
South Central

In disturbance-prone ecosystems, fitness consequences of plant reproductive strategies are often determined by the relative timing of seed production and disturbance events, but the role of disturbances as proximate drivers of seed production has been overlooked. We use long-term data on seed production in Quercus chapmanii , Q. geminata and Q. inopina , rhizomatous oaks found in south central Florida's oak scrub, to investigate the role of fire history and its interaction with weather in shaping acorn production and its synchrony . Acorn production increased with the time since last fire, combined with additive or interactive effects of spring precipitation (+) or drought (–). Furthermore, multiple matrix regression models revealed that ramet pairs with shared fire history were more synchronous in seed production than ones that burned in different years. Long-term trends suggest that increasingly drier spring weather, in interaction with fire frequency, may drive a decline of seed production. Such declines could affect the community of acorn-reliant vertebrates in the Florida scrub, including endangered Florida scrub-jays ( Aphelocoma coerulescens ). These results illustrate that fire can function as a proximate driver of seed production in mast-seeding species, highlighting the increasingly recognized importance of interactions among reproductive strategies and disturbance regimes in structuring plant populations and communities. This article is part of the theme issue ‘The ecology and evolution of synchronized seed production in plants’.

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