Anthropogenic forces are projected to lead to warmer temperatures and altered precipitation patterns globally. The impact of these climatic changes on the uptake of carbon by the land surface will, in part, determine the rate and magnitude of these changes. However, there is a great deal of uncertainty in how terrestrial ecosystems will respond to climate in the future. Here, we used a fully fa...

Effects of moderate heat on growth and photosynthesis were investigated in two clonal genotypes of Acer rubrum L., originally collected from the thermally contrasting habitats of Florida and Minnesota, USA, and known in the horticultural trade for sensitivity and insensitivity to heat, respectively. Under both common garden and warm greenhouse conditions (day/night temperature of 33/25 degrees ...

The effect of ozone (03) on ribulose bisphosphate carboxylase/ oxygenase (Rubisco) activity and quantity and net photosynthesis in greenhouse-grown Solanum tuberosum L. cv 'Norland' foliage was studied in relation to oxidant-induced premature senescence. Plants, 26 days old, were exposed to 0.06 to 0.08 microliters per liter 03 from 1000 to 1600 hours for 4 days in a controlled environment cham...

We investigate the utility of an improved isotopic method to partition the net ecosystem exchange of CO2 (F) into net photosynthesis (FA) and nonfoliar respiration (FR). Measurements of F and the carbon isotopic content in air at a high-elevation coniferous forest (the Niwot Ridge AmeriFlux site) were used to partition F into FA and FR. Isotopically partitioned fluxes were then compared with an...

Coral reefs are facing rapidly changing environments, but implications for reef ecosystem functioning and important services, such as productivity, are difficult to predict. Comparative investigations on coral reefs that are naturally exposed to differing environmental settings can provide essential information in this context. One prevalent phenomenon regularly introducing alterations in water...

Quantifying impacts of ecological disturbance on ecosystem carbon and water fluxes will improve predictive understanding of biosphere—atmosphere feedbacks. Tree mortality caused by mountain pine bark beetles (Dendroctonus ponderosae) is hypothesized to decrease photosynthesis and water flux to the atmosphere while increasing respiration at a rate proportional to mortality. This work uses data f...

We investigated diurnal and seasonal changes in carbon acquisition and partitioning of recently assimilated carbon in fast- and slow-growing families of loblolly pine (Pinus taeda L.) to determine whether fast-growing families exhibited greater carbon gain at the leaf level. Since planting on a xeric infertile site in Scotland County, NC, USA in 1993, five Atlantic Coastal Plain (ACP) and five ...

Plant tolerance to herbivory is a key approach for managing pests. In alfalfa, Medicago sativa, the potato leafhopper, Empoasca fabae, is a major pest as a result of the cascade of plant responses to piercing-sucking injury. To identify tolerance to its injury based on alfalfa physiology, experiments were conducted in the field and greenhouse. In our comparison of the response of field-grown al...

Wilt disease of watermelon caused by Fusarium oxysporum f. sp. niveum in long-term monoculture system has been much often found particularly in protected land cultivation system worldwide. Fusaric acid (FA), a fungal phytotoxin, was extracted from F. oxysporum f. sp. niveum isolated from diseased watermelon plant. The influence of FA on the biomass and leaves photosynthesis of watermelon seedli...

Coral reefs are facing major global and local threats due to climate change-induced increases in dissolved inorganic carbon (DIC) and because of land-derived increases in organic and inorganic nutrients. Recent research revealed that high availability of labile dissolved organic carbon (DOC) negatively affects scleractinian corals. Studies on the interplay of these factors, however, are lacking...