02253nas a2200265   4500008004100000245013500041210006900176300001300245490000700258520141500265100001801680700001301698700001601711700001801727700001801745700001601763700001201779700001401791700002001805700001401825700002301839700001901862700001601881856009001897       2010                        eng d00aVariation in gene expression of Andropogon gerardii in response to altered environmental conditions associated with climate change0 aVariation in gene expression of Andropogon gerardii in response   a374 -3830 v983 a<p>1.&ensp;If we are to understand the mechanisms underlying species responses to climate change in natural systems, studies are needed that focus on responses of non-model species under field conditions. We measured transcriptional profiles of individuals of Andropogon gerardii, a C4 grass native to North American grasslands, in a field experiment in which both temperature and precipitation were manipulated to simulate key aspects of forecasted climate change. 2.&ensp;By using microarrays developed for a closely related model species, Zea mays, we were able to compare the relative influence of warming versus altered soil moisture availability on expression levels of over 7000 genes, identify responsive functional groups of genes and correlate changes in gene transcription with physiological responses. 3.&ensp;We observed more statistically significant shifts in transcription levels of genes in response to thermal stress than in response to water stress. We also identified candidate genes that demonstrated transcription levels closely associated with physiological variables, in particular chlorophyll fluorescence. 4.Synthesis. These results suggest that an ecologically important species responds differently to different environmental aspects of forecast climate change. These translational changes have the potential to influence phenotypic characters and ultimately adaptive responses.</p>1 aTravers, S.E.1 aTang, Z.1 aCaragea, D.1 aGarrett, K.A.1 aHulbert, S.H.1 aLeach, J.E.1 aBai, J.1 aSaleh, A.1 aKnapp, Alan, K.1 aFay, P.A.1 aNippert, Jesse, B.1 aSchnable, P.S.1 aSmith, M.D.  uhttps://besjournals.onlinelibrary.wiley.com/doi/full/10.1111/j.1365-2745.2009.01618.x01450nas a2200145   4500008004100000245008200041210006900123300001300192490000800205520092200213653002301135100002001158700001601178856011001194       2001                        eng d00aVariation among biomes in temporal dynamics of aboveground primary production0 aVariation among biomes in temporal dynamics of aboveground prima  a481 -4840 v2913 aInterannual variability in aboveground net primary production (ANPP) was assessed with long-term (mean = 12 years) data from 11 Long Term Ecological Research sites across North America. The greatest interannual variability in ANPP occurred in grasslands and old fields, with forests the least variable. At a continental scale, ANPP was strongly correlated with annual precipitation. However, interannual variability in ANPP was not related to variability in precipitation. Instead, maximum variability in ANPP occurred in biomes where high potential growth rates of herbaceous vegetation were combined with moderate variability in precipitation. In the most dynamic biomes, ANPP responded more strongly to wet than to dry years. Recognition of the fourfold range in ANPP dynamics across biomes and of the factors that constrain this variability is critical for detecting the biotic impacts of global change phenomena.10aPrimary production1 aKnapp, Alan, K.1 aSmith, M.D.  uhttp://lter.konza.ksu.edu/content/variation-among-biomes-temporal-dynamics-aboveground-primary-production02238nas a2200133   4500008004100000245009100041210006900132300001300201490000700214520179700221100002002018700001702038856004902055       1998                        eng d00aVariability in leaf optical properties among 26 species from a broad range of habitats0 aVariability in leaf optical properties among 26 species from a b  a940 -9460 v853 aLeaves from 26 species with growth forms from annual herbs to trees were collected from open, intermediate, and shaded understory habitats in Mississippi and Kansas, USA. Leaf optical properties including reflectance, transmittance, and absorptance in visible and near infrared (NIR) wavelengths were measured along with leaf thickness and specific leaf mass (SLM). These leaf properties and internal light scattering have been reported to vary with light availability in studies that have focused on a limited number of species. Our objective was to determine whether these patterns in leaf optics and light availability were consistent when a greater number of species were evaluated. Leaf thickness and SLM varied by tenfold among species sampled, but within-habitat variance was high. Although there was a strong trend toward thicker leaves in open habitats, only SLM was significantly greater in open vs. understory habitats. In contrast, leaf optical properties were strikingly similar among habitats. Reflectance and reflectance/transmittance in the NIR were used to estimate internal light scattering and there were strong relationships (r1 &gt; 0.65) between these optical properties and leaf thickness. We concluded that leaf thickness, which did not vary consistently among habitats, was the best predictor of NIR reflectance and internal light scattering. However, because carbon allocation to leaves was lower in understory species (low SLM) yet gross optical properties were similar among all habitats, the energy investment by shade leaves required to achieve optical equivalence with sun leaves was lower. Differences in leaf longevity and growth form within a habitat may help explain the lack of consistent patterns in leaf optics as the number of species sampled increases.1 aKnapp, Alan, K.1 aCarter, G.A.  uhttp://www.amjbot.org/content/85/7/940.short