Ecological correlates of stress for a habitat generalist in a biofuels landscape

2013 ◽  
Vol 91 (12) ◽  
pp. 853-858 ◽  
Author(s):  
S.L. Fredebaugh-Siller ◽  
C.D. Suski ◽  
Z.C. Zuckerman ◽  
R.L. Schooley
Keyword(s):  
Stress Responses ◽  
Habitat Structure ◽  
Panicum Virgatum ◽  
Meadow Vole ◽  
Deer Mice ◽  
Generalist Species ◽  
Biofuel Crops ◽  
Stress Levels ◽  
Habitat Generalist ◽  
Mixed Prairie

Understanding the success of habitat generalist species requires knowledge of how individuals respond to stressors that vary across habitats within landscapes. Habitat structure can affect stress by altering predation risk, conspecific densities, and densities of heterospecific competitors. Increased demand for biofuels will alter habitat structure for species in agroecosystems worldwide. We measured stress responses of deer mice (Peromyscus maniculatus (Wagner, 1845)), a widespread habitat generalist, in a biofuels landscape. We quantified fecal corticosterone concentrations for individuals in four biofuel crops: switchgrass (Panicum virgatum L.), miscanthus (Miscanthus × giganteus Greef & Deuter ex Hodkinson & Renvoize), mixed prairie, and corn (Zea mays L.). We also evaluated stress responses of deer mice to the annual harvesting of corn. Deer mice inhabiting switchgrass and mixed prairie had higher fecal corticosterone concentrations compared with mice in corn and miscanthus. Fecal corticosterone concentrations correlated positively with abundances of conspecifics and behaviorally dominant voles (prairie vole, Microtus ochrogaster (Wagner, 1842); meadow vole, Microtus pennsylvanicus (Ord, 1815)) across habitats. Stress levels of deer mice depended on how habitat structure modified the competitive environment. Deer mice did not exhibit increased fecal corticosterone concentrations in response to corn harvest, a rapid and extensive habitat disturbance common to agroecosystems. Our research is the first to investigate how landscape change due to biofuels expansion can affect stress levels of individuals.

scholarly journals Genome-Wide Analysis of the TCP Gene Family in Switchgrass (Panicum virgatum L.)

2019 ◽  
Vol 2019 ◽  
pp. 1-13 ◽  
Author(s):  
Yuzhu Huo ◽  
Wangdan Xiong ◽  
Kunlong Su ◽  
Yu Li ◽  
Yawen Yang ◽  
...  
Keyword(s):  
Salt Stress ◽  
Plant Growth ◽  
Gene Family ◽  
Stress Responses ◽  
Panicum Virgatum ◽  
Expression Profiles ◽  
Specific Expression ◽  
Genome Wide Analysis ◽  
Genome Wide ◽  
A Genome

The plant-specific transcription factor TCPs play multiple roles in plant growth, development, and stress responses. However, a genome-wide analysis of TCP proteins and their roles in salt stress has not been declared in switchgrass (Panicum virgatum L.). In this study, 42 PvTCP genes (PvTCPs) were identified from the switchgrass genome and 38 members can be anchored to its chromosomes unevenly. Nine PvTCPs were predicted to be microRNA319 (miR319) targets. Furthermore, PvTCPs can be divided into three clades according to the phylogeny and conserved domains. Members in the same clade have the similar gene structure and motif localization. Although all PvTCPs were expressed in tested tissues, their expression profiles were different under normal condition. The specific expression may indicate their different roles in plant growth and development. In addition, approximately 20 cis-acting elements were detected in the promoters of PvTCPs, and 40% were related to stress response. Moreover, the expression profiles of PvTCPs under salt stress were also analyzed and 29 PvTCPs were regulated after NaCl treatment. Taken together, the PvTCP gene family was analyzed at a genome-wide level and their possible functions in salt stress, which lay the basis for further functional analysis of PvTCPs in switchgrass.

scholarly journals Assembly and seasonality of core phyllosphere microbiota on perennial biofuel crops

2019 ◽  
Vol 10 (1) ◽  
Author(s):  
Keara L. Grady ◽  
Jackson W. Sorensen ◽  
Nejc Stopnisek ◽  
John Guittar ◽  
Ashley Shade
Keyword(s):  
Crop Production ◽  
Panicum Virgatum ◽  
Gene Diversity ◽  
Perennial Grasses ◽  
Biofuel Production ◽  
Rrna Gene ◽  
Miscanthus X Giganteus ◽  
Growing Seasons ◽  
Biofuel Crops ◽  
Ecological Filtering

Abstract Perennial grasses are promising feedstocks for biofuel production, with potential for leveraging their native microbiomes to increase their productivity and resilience to environmental stress. Here, we characterize the 16S rRNA gene diversity and seasonal assembly of bacterial and archaeal microbiomes of two perennial cellulosic feedstocks, switchgrass (Panicum virgatum L.) and miscanthus (Miscanthus x giganteus). We sample leaves and soil every three weeks from pre-emergence through senescence for two consecutive switchgrass growing seasons and one miscanthus season, and identify core leaf taxa based on occupancy. Virtually all leaf taxa are also detected in soil; source-sink modeling shows non-random, ecological filtering by the leaf, suggesting that soil is an important reservoir of phyllosphere diversity. Core leaf taxa include early, mid, and late season groups that were consistent across years and crops. This consistency in leaf microbiome dynamics and core members is promising for microbiome manipulation or management to support crop production.

Epiphyte Flora and Diversity on Basal Trunks of Six Old-Growth Forest Tree Species in Southern and Middle Boreal Finland

1996 ◽  
Vol 28 (5) ◽  
pp. 443-463 ◽  
Author(s):  
Mikko Kuusinen
Keyword(s):  
Tree Species ◽  
Boreal Forests ◽  
Forest Tree ◽  
Old Growth ◽  
Epiphytic Lichen ◽  
Generalist Species ◽  
Salix Caprea ◽  
Forest Tree Species ◽  
Old Growth Forest ◽  
Habitat Generalist

AbstractEpiphytic lichen and bryophyte species composition, richness and diversity were surveyed on basal trunks of six common old-growth forest tree species, Picea abies, Pinus sylvestris, Betula pendula, Alnus incana, Salix caprea and Populus tremula, in two old-growth forest areas, one in southern and one in middle boreal Finland. The average species numbers per tree ranged from 18 (Picea) to 27 (Salix) in the southern and from 20 (Populus) to 31 (Salix) in the middle boreal area. A few widespread habitat-generalist species, such as the foliose lichens Hypogymnia physodes and Platismatia glauca, were most abundant on all the tree species, except Populus. Most other epiphyte species showed at least a slight preference for one or two tree species. Populus proved to have the most distinct flora characterized by the abundance of certain, rather specialized crustose lichens and bryophytes. The number of species that occurred on only one tree species was highest on Populus (9) in the southern and on Alnus (18) in the middle boreal area. Differences in bark acidity and structure were the most likely explanations for the differences between tree species in the epiphytic flora and diversity. Salix and Populus were the most important of the tree species studied for the conservation of epiphyte diversity in the boreal forests of Finland.

scholarly journals Digesting the indigestible: Biosynthesis of the plant secondary wall

2011 ◽  
Vol 33 (2) ◽  
pp. 24-28
Author(s):  
Raymond Wightman ◽  
Simon Turner
Keyword(s):  
Cell Walls ◽  
Panicum Virgatum ◽  
Second Generation ◽  
Plant Biomass ◽  
Biofuel Production ◽  
Bioenergy Crops ◽  
Second Generation Biofuels ◽  
Biofuel Crops ◽  
Secondary Cell Walls ◽  
Micro Organisms

Biofuels have recently been the subject of intense debate with regard to‘food versus fuel’. Consequently, attention has focused upon so-called ‘second-generation’ biofuels that use alternatives to food-based feedstocks. In the best-developed forms of second-generation biofuels, sugars from starch digestion could be replaced with sugars released from the plant cell walls. This biomass could come from either agricultural residue, such as part of the maize culm, or from purpose grown biofuel crops, such as Miscanthus or Switchgrass (Panicum virgatum), that generate huge yields even when grown on marginal land with minimal agricultural inputs. For these and other potential bioenergy crops such as trees, the majority of the plant biomass is composed of woody secondary cell walls. If all cell wall sugars were readily accessible to fermenting micro-organisms, a 5 kg log could theoretically produce up to 2.5 litres of ethanol. The secondary cell walls are frequently the first line of defence against pests and pathogens, as well as providing structure and support for upward plant growth (Figure 1). Consequently, by their very nature, secondary cell walls are designed for strength and to resist degradation. The compact organization of the wall makes its digestion, a process known as saccharification, very difficult so biomass is currently too costly to be a viable feedstock. Knowledge of how the walls are constructed, however, would allow us to efficiently deconstruct them. This article gives an overview of secondary walls and potential modifications expected to be beneficial to improved biofuel production.

scholarly journals Psychological stress levels and autonomic activity in everyday life are related to stress responses in the laboratory

2012 ◽  
Vol 3 (0) ◽  
Author(s):  
Nadine Skoluda ◽  
Johanna Marie Doerr ◽  
Urs Markus Nater ◽  
Myriam V. Thoma ◽  
Ulrike Ehlert
Keyword(s):  
Everyday Life ◽  
Psychological Stress ◽  
Stress Responses ◽  
Autonomic Activity ◽  
Stress Levels

Influence of alternative conifer release treatments on habitat structure and small mammal populations in south central British Columbia

1996 ◽  
Vol 26 (11) ◽  
pp. 2023-2034 ◽  
Author(s):  
J. Bruce Runciman ◽  
Thomas P. Sullivan
Keyword(s):  
British Columbia ◽  
Small Mammal ◽  
Habitat Structure ◽  
Woody Debris ◽  
Deciduous Tree ◽  
Deer Mice ◽  
Mammal Species ◽  
South Central ◽  
Cut Stump ◽  
And Control

This study was designed to test the hypothesis that conifer release treatments would simplify habitat structure and reduce small mammal populations in forest plantations. A secondary objective was to examine some important demographic characteristics, for selected small mammal species, that may be affected by changes in habitat. We examined the effects of manual cutting and cut-stump applications of glyphosate herbicide on vegetation, woody debris, and small mammal populations from 1991 to 1994 in young mixed-conifer plantations of south central British Columbia, Canada. The experimental design consisted of 9 separate and independent plantations: 3 controls, 3 manual treatments, and 3 cut-stump treatments. Total volumes of herbs, shrubs, coniferous trees, and woody debris were not affected by manual or cut-stump treatments for conifer release. Both treatments reduced total volumes of deciduous trees in the first posttreatment year. However, deciduous tree volumes on manual treatments had largely returned to pretreatment levels by the second posttreatment year. There were no significant (P > 0.05) effects of manual or cut-stump treatments on the population size of deer mice (Peromyscusmaniculatus Wagner), yellow-pine chipmunks (Tamiasamoenus J.A. Allen), southern red-backed voles (Clethrionomysgapped Vigors), or long-tailed voles (Microtuslongicaudus Merriam). The response of meadow voles (Microtuspennsylvanicus Ord) was variable. Sex ratios, body weights, reproduction, recruitment, and survival of deer mice remained similar on treatment and control plantations throughout this study. Changes in habitat structure up to 2 years posttreatment did not appear to exceed the tolerance of small mammal populations for early successional change.

Co-occurrence patterns of rodents at multiple spatial scales: competitive release of generalists following habitat loss?

2019 ◽  
Vol 100 (4) ◽  
pp. 1229-1242 ◽  
Author(s):  
Thomas Püttker ◽  
Camila S Barros ◽  
Bruno T Pinotti ◽  
Adriana A Bueno ◽  
Renata Pardini
Keyword(s):  
Habitat Loss ◽  
Spatial Scales ◽  
Niche Partitioning ◽  
Large Data ◽  
Data Set ◽  
Generalist Species ◽  
Competitive Release ◽  
Spatial Niche ◽  
Habitat Generalist ◽  
Occurrence Patterns

AbstractTheory predicts that habitat generalist species are excluded by specialist species in optimal habitat for specialists, and empirical data commonly show a shift from specialist- to generalist-dominated communities following disturbance. We investigated co-occurrence patterns of habitat generalist and specialist terrestrial rodents at two spatial scales in the Atlantic Forest, aiming at evaluating the following hypotheses: 1) within-patch spatial niche partitioning promotes coexistence of generalists and specialists, leading to checkerboard presence-absence patterns at small (within-patch) rather than large (among-patch) scales; and 2) the decrease in abundance of specialists due to habitat loss promotes a competitive release of generalists, leading to negative covariance in abundance between generalists and specialists among patches. Drawing on a large data set including 363 sites within three patches in continuous forest, and 45 patches within three landscapes, we used C-scores based on presence-absence and abundance data to evaluate spatial segregation. We found consistent segregation between specialists and generalists at the within-patch rather than among-patch scale, but no consistent negative covariance in abundance between generalists and specialists among patches (as covarying species pairs varied across landscapes). Our findings suggest that spatial patterns caused by competition are scale-dependent, and coexistence of generalists and specialists is promoted by within-patch spatial niche partitioning. However, the influence of competitive release on the proliferation of generalists may be outweighed by other factors in fragmented landscapes.A teoria ecológica prevê que espécies generalistas de habitat são excluídas por espécies especialistas em hábitats ótimos para as especialistas, e dados empíricos comumente mostram uma mudança de dominância das comunidades - de especialistas para generalistas - após distúrbios. Nós investigamos os padrões de coocorrência de roedores terrestres generalistas e especialistas de habitat em duas escalas espaciais na Mata Atlântica, para testar as seguintes hipóteses: 1) a partição espacial do nicho dento de fragmentos promove a coexistência de generalistas e especialistas, levando a padrões de presença-ausência “tabuleiro de damas” em escalas pequenas (dentro de fragmento) mas não em escalas grandes (entre fragmentos); 2) a diminuição da abundância de especialistas devido à perda de habitat promove uma liberação competitiva de generalistas, levando a covariância negativa da abundância de generalistas e especialistas entre fragmentos. A partir de um grande banco de dados - 363 sítios dentro de três fragmentos de floresta contínua, e 45 fragmentos dentro de três paisagens, usamos C-scores baseados em dados de presença/ausência e abundância para avaliar a segregação espacial. Encontramos segregação consistente entre especialistas e generalistas na escala menor (dentro de fragmentos) e não na maior (entre fragmentos), mas não encontramos covariância negativa na abundância de generalistas e especialistas entre fragmentos (dado que os pares de espécies que covariaram mudou entre as paisagens). Nossos resultados sugerem que padrões espaciais causados por competição são dependentes de escala, e que a coexistência de generalistas e especialistas é promovida pela partição espacial de nicho dentro dos fragmentos. No entanto, a influência da liberação competitiva na proliferação de generalistas pode ser superada por outros fatores em paisagens fragmentadas.

scholarly journals Urbanization alters the abundance and composition of predator communities and leads to aphid outbreaks on urban trees

2020 ◽  
Author(s):  
Dávid Korányi ◽  
Viktor Szigeti ◽  
László Mezőfi ◽  
Előd Kondorosy ◽  
Viktor Markó
Keyword(s):  
Urban Environments ◽  
Urban Trees ◽  
Dispersal Ability ◽  
Abundance Pattern ◽  
Acer Campestre ◽  
Generalist Species ◽  
Predator Prey ◽  
Habitat Generalist ◽  
Filtering Effect ◽  
Predatory Arthropods

Abstract Urbanization can affect arthropod abundance in different ways. While species with narrow habitat range and low dispersal ability often respond negatively to urban environments, many habitat generalist species with good dispersal ability reach high densities in city centers. This filtering effect of urban habitats can strongly influence predator-prey-mutualist interactions and may therefore affect the abundance of predatory and phytophagous species both directly and indirectly. Here, we assessed the effect of urbanization on aphids, predatory arthropods, and ants on field maple (Acer campestre) trees in and around the city of Budapest, Hungary. We used the percentage of impervious surfaces within a 500 m radius of each site as an index of the degree of urbanization. We found that the abundance of aphids increased with increasing level of urbanization. However, abundance of predatory arthropods and occurrence of poorly dispersing species within the predator community were negatively related to urbanization, and we identified these two independent factors as significant predictors of aphid abundances. The abundance of ants decreased with urbanization, and contrary to our expectations, did not affect the abundance pattern of aphids. Our results suggest that urbanization, by altering the abundance and composition of predator communities, can disrupt biological control of aphid populations, and thus may contribute to the aphid outbreaks on urban trees.

scholarly journals Arousal Predisposition as a Vulnerability Indicator for Psychosis: A General Population Online Stress Induction Study

2015 ◽  
Vol 2015 ◽  
pp. 1-8 ◽  
Author(s):  
Annika Clamor ◽  
A. Malika Warmuth ◽  
Tania M. Lincoln
Keyword(s):  
Stress Response ◽  
Stress Responses ◽  
Population Sample ◽  
Explanatory Models ◽  
Self Report ◽  
Psychotic Symptoms ◽  
Cross Sectional ◽  
Stress Levels ◽  
Before And After ◽  
Vulnerability Indicator

Explanatory models ascribe to arousability a central role for the development of psychotic symptoms. Thus, a disposition to hyperarousal (i.e., increased arousal predisposition (AP)) may serve as an underlying vulnerability indicator for psychosis by interacting with stressors to cause symptoms. In this case, AP, stress-response, and psychotic symptoms should be linked before the development of a diagnosable psychotic disorder. We conducted a cross-sectional online study in a population sample (N=104;Mage=27.7years,SD=11.2, range 18–70). Participants rated their AP and subclinical psychotic symptoms. Participants reported their stress-levels before and after two stress inductions including an arithmetic and a social stressor. The participants with an increased AP generally felt more stressed. However, AP was not associated with the specific stress-response. As expected, positive psychotic symptoms were significantly associated with AP, but this was not mediated by general stress-levels. Its association to subtle, nonclinical psychotic symptoms supports our assumption that AP could be a vulnerability indicator for psychosis. The trait is easily accessible via a short self-report and could facilitate the identification of people at risk and be a promising target for early stress-management. Further research is needed to clarify its predictive value for stress-responses.

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