02808nas a2200241 4500008004100000245008400041210006900125300001100194490000600205520207100211653001302282653000902295653001502304653002502319653001602344653001802360100002302378700002902401700002002430700001702450700001902467856008002486 2019 eng d00aTemperature effects on performance and physiology of two prairie stream minnows0 aTemperature effects on performance and physiology of two prairie acoz0630 v73 a
Earth’s atmosphere has warmed by ~1°C over the past century and continues to warm at an increasing rate. Effects of atmospheric warming are already visible in most major ecosystems and are evident across all levels of biological organization. Linking functional responses of individuals to temperature is critical for predicting responses of populations and communities to global climate change. The southern redbelly dace Chrosomus erythrogaster and the central stoneroller Campostoma anomalum are two minnows (Cyprinidae) that commonly occur in the Flint Hills region of the USA but show different patterns of occurrence, with dace largely occupying headwater reaches and stonerollers persisting in both headwater and intermediate-sized streams. We tested for differences between species in critical thermal maximum, energy metabolism, sustained swimming and activity over an ecologically relevant temperature gradient of acclimation temperatures. Typically, metrics increased with acclimation temperature for both species, although stoneroller activity decreased with temperature. We observed a significant interaction between species and temperature for critical thermal maxima, where stonerollers only had higher critical thermal maxima at the coldest temperature and at warm temperatures compared to the dace. We did not find evidence suggesting differences in the energy metabolism of dace and stonerollers. We detected interspecific differences in sustained swimming performance, with dace having higher swimming speed than stonerollers regardless of acclimation temperature. Finally, there was a significant interaction between temperature and species for activity; dace activity was higher at intermediate and warm temperatures compared to stonerollers. We observed subtle interspecific differences in how performance metrics responded to temperature that did not always align with observed patterns of distribution for these species. Thus, other ecological factors likely are important drivers of distributional patterns in these species.
10aActivity10afish10ametabolism10aswimming performance10aTemperature10athermal limit1 aFrenette, Bryan, D1 aBruckerhoff, Lindsey, A.1 aTobler, Michael1 aGido, K., B.1 aClark, Timothy uhttps://academic.oup.com/conphys/article-pdf/7/1/coz063/30337107/coz063.pdf03097nas a2200205 4500008004100000245012700041210006900168260004300237490001400280520240300294653001402697653002502711653002702736653002402763653001602787653001602803100001602819700001902835856003702854 2011 eng d00aA generalist grasshopper species (Melanoplus femurrubrum) is adapted to variable environments along a latitudinal gradient0 ageneralist grasshopper species Melanoplus femurrubrum is adapted aManhattan, KSbKansas State University0 vMS Thesis3 aTemperature and food quality vary across broad latitudinal gradients, greatly affecting performance by insect herbivores. The contribution of each varies latitudinally so that geographically distinct populations are challenged by differences in nutritional needs and energetic demands. While there has been extensive work studying diet selectivity and nutritional ecology of insect herbivores, few studies have focused on how insect herbivores adapt across such vast environmental gradients. The generalist-feeding grasshopper, Melanoplus femurrubrum (DeGreer), has a broad geographic range that extends across much of North America, making this species ideal for comparative investigations of intrinsic performance responses to extensive but predictable patterns of environmental variation. I compared responses by six populations collected from populations located from Texas to North Dakota (USA) using a common garden experimental design to investigate clinal responses in grasshopper performance. I examined responses in: (1) body size, (2) thermoregulation and adaptive coloration, (3) developmental and growth rates, (4) metabolic rates, (5) total consumption and rates, (6) diet ratio selection, and (7) digestive processing efficiencies across the latitudinal gradient. Grasshopper body size followed the Converse Bergmann’s Rule with decreasing body size as latitude increased. Temperature influenced all other responses, but responses to diet were not always significant or directional. Latitudinal trends for development and growth rates were observed but mass-specific metabolic rates were similar for all populations. Total consumption was body size dependent but independent of diet type. Mass-specific consumption varied but no single directional trend was detected. There was a shift in carbohydrate-biased diet preference at low latitude toward protein-biased diet ratios at higher latitudes, suggesting adaptations to different energetic demands by these populations. However, post-ingestive (digestive) efficiencies demonstrated variable responses with northern populations observing highest efficiencies for some indices but not all. Overall, this research documents phenotypic plasticity to environmental variability to some degree for digestive efficiencies, but ecotypic responses in body size and diet preference among M. femurrubrum populations were observed.
10abody size10alatitudinal gradient10aMelanoplus femurrubrum10anutritional ecology10aPerformance10aTemperature1 aParsons, S.1 aJoern, Anthony uhttp://hdl.handle.net/2097/1309302383nas a2200241 4500008004100000245014700041210006900188300001300257490000700270520158200277653003001859653002501889653002201914653001501936653001501951653001901966653002301985653001602008100001902024700002202043700001702065856005902082 2008 eng d00aEffects of grazing minnows (Phoxinus erythrogaster) and crayfish (Orconectes nais and O. neglectus) on stream ecosystem structure and function0 aEffects of grazing minnows Phoxinus erythrogaster and crayfish O a772 -7820 v273 aWe compared the effects of 2 common grazers, southern redbelly dace (Phoxinus erythrogaster) and crayfish (Orconectes spp.), on ecosystem structure and function in experimental streams with pool and riffle habitats. Our goal was to identify potentially overlapping roles of these grazers in these systems. Measures of ecosystem structure included algal filament length, particulate organic matter (POM), densities of invertebrate taxa, and algal biomass. Ecosystem function was measured as gross primary productivity (GPP). Biomass-dependent effects of crayfish and dace on ecosystem properties were compared in autumn 2005 when mean water temperature was 12.9°C (range 7.6–27.9°C). Increasing crayfish biomass did not influence ecosystem properties, but increasing dace biomass negatively affected algal filament length and chironomid abundance and positively affected chydorid abundance. Effects of moderately high biomasses of dace and crayfish were compared in spring 2006 when mean water temperature was 21.4°C (range 17.5–29.9°C). Algal filament lengths were generally low relative to values obtained in autumn 2005 in both dace and crayfish treatments. In addition, algal filament length was shorter and chironomid density was lower in crayfish than in dace streams. The contrasting effects of dace and crayfish across sampling days, seasons, and habitats led us to hypothesize that physiological and behavioral traits of these species might limit the redundancy of their effects on ecosystems across broad spatial and temporal scales.
10acontext-dependent effects10aexperimental streams10aforaging behavior10aperiphyton10aphysiology10aPrairie stream10aPrimary production10aTemperature1 aBengtson, J.R.1 aEvans-White, M.A.1 aGido, K., B. uhttps://www.journals.uchicago.edu/doi/10.1899/07-136.101406nas a2200193 4500008004100000245009300041210006900134300001100203490000600214520074700220653001900967653001700986653001601003653001401019100001601033700001901049700001901068856012501087 2007 eng d00aInsect development under predation risk, variable temperature, and variable food quality0 aInsect development under predation risk variable temperature and a47 -650 v43 aWe model the development of an individual insect, a grasshopper, through its nymphal period as a function of a trade-off between prey vigilance and nutrient intake in a changing environment. Both temperature and food quality may be variable. We scale up to the population level using natural mortality and a predation risk that is mass, vigilance, and temperature dependent. Simulations reveal the sensitivity of both survivorship and development time to risk and nutrient intake, including food quality and temperature variations. The model quantifies the crucial role of temperature in trophic interactions and development, which is an important issue in assessing the effects of global climate change on complex environmental interactions.10aeco-physiology10agrasshoppers10aTemperature10avigilance1 aLogan, J.D.1 aWolesensky, W.1 aJoern, Anthony uhttp://lter.konza.ksu.edu/content/insect-development-under-predation-risk-variable-temperature-and-variable-food-quality02113nas a2200205 4500008004100000245007200041210006900113300001300182490000800195520145400203653001701657653002001674653001401694653002701708653001601735100001601751700001901767700001901786856010201805 2006 eng d00aTemperature- dependent phenology and predation in arthropod systems0 aTemperature dependent phenology and predation in arthropod syste a471 -4820 v1963 aA central issue in ecology is to determine how environmental variations associated with global climate change, especially changing temperatures, affect trophic interactions in various ecosystems. This paper develops a temperature-dependent, stage-based, discrete, cohort model of the population dynamics of an insect pest under pressure from a predator. Guided by experimental data, the model is applied specifically to predation of grasshoppers by rangeland lycosid spiders. The development rate of insect arthropods is strongly affected by temperature, and these temperature-dependent phenological effects couple with shifts in the daily activity periods for both prey and predator, thereby increasing or decreasing opportunities for interaction. The model addresses these effects quantitatively by introducing a temperature-dependent, joint-activity factor that enters the predator’s functional response. The model also includes a prey mortality rate that is temperature-dependent through the prey development rate. The model is parameterized using field and experimental data for spiders and grasshoppers. We investigate the effect of the solar power index (sunlight), mean temperature, and temperature variation, as measured by amplitude, on the developmental times and survivorship both with, and without, predation. We conclude that increasing variation in temperature results in a stronger relative effect on survivorship due to predation.10agrasshoppers10aLycosid spiders10aphenology10aPredator–prey models10aTemperature1 aLogan, J.D.1 aWolesensky, W.1 aJoern, Anthony uhttp://lter.konza.ksu.edu/content/temperature-dependent-phenology-and-predation-arthropod-systems