Elevated CO2 differentially alters belowground plant and soil microbial community structure in reed canary grass-invaded experimental wetlands
نویسندگان
چکیده
Several recent studies have indicated that an enriched atmosphere of carbon dioxide (CO2) could exacerbate the intensity of plant invasions within natural ecosystems, but little is known of how rising CO2 impacts the belowground characteristics of these invaded systems. In this study, we examined the effects of elevated CO2 and nitrogen (N) inputs on plant and soil microbial community characteristics of plant communities invaded by reed canary grass, Phalaris arundinacea L. We grew the invasive grass under two levels of invasion: the invader was either dominant (high invasion) at 490% plant cover or sub-dominant (low invasion) at o50% plant cover. Experimental wetland communities were grown for four months in greenhouses that received either 600 or 365ml l 1 (ambient) CO2. Within each of three replicate rooms per CO2 treatment, the plant communities were grown under high (30mg l ) or low (5mg l ) N. In contrast to what is often predicted under N limitation, we found that elevated CO2 increased native graminoid biomass at low N, but not at high N. The aboveground biomass of reed canary grass did not respond to elevated CO2, despite it being a fast-growing C3 species. Although elevated CO2 had no impact on the plant biomass of heavily invaded communities, the relative abundance of several soil microbial indicators increased. In contrast, the moderately invaded plant communities displayed increased total root biomass under elevated CO2, while little impact occurred on the relative abundance of soil microbial indicators. Principal components analysis indicated that overall soil microbial community structure was distinct by CO2 level for the varying N and invasion treatments. This study demonstrates that even when elevated CO2 does not have visible effects on aboveground plant biomass, it can have large impacts belowground. r 2006 Elsevier Ltd. All rights reserved.
منابع مشابه
Metagenomic analysis reveals a marked divergence in the structure of belowground microbial communities at elevated CO2.
Understanding the responses of biological communities to elevated CO2 (eCO2) is a central issue in ecology, but little is known about the influence of eCO2 on the structure and functioning (and consequent feedbacks to plant productivity) of the belowground microbial community. Here, using metagenomic technologies, we showed that 10 years of field exposure of a grassland ecosystem to eCO2 dramat...
متن کاملEffect of elevated CO2 and drought on soil microbial communities associated with Andropogon gerardii.
Our understanding of the effects of elevated atmospheric CO2, singly and in combination with other environmental changes,on plant-soil interactions is incomplete. Elevated CO2 effects on C4 plants, though smaller than on C3 species, are mediated mostly via decreased stomatal conductance and thus water loss. Therefore, we characterized the interactive effect of elevated CO2 and drought on soil m...
متن کاملExtracellular Enzyme Activity Beneath Temperate Trees Growing Under Elevated Carbon Dioxide and Ozone
cause these plant tissues are the primary substrates for microbial metabolism in soil. Soil microorganisms are limited by the amount and type of plantOzone is a greenhouse gas that is accumulating in the derived substrates entering soil, and we reasoned that changes in the production and biochemical constituents of plant litter produced lower atmosphere, and elevated O3 has the potential to und...
متن کاملElevated enzyme activities in soils under the invasive nitrogen-fixing tree Falcataria moluccana
Like other N-fixing invasive species in Hawaii, Falcataria moluccana dramatically alters forest structure, litterfall quality and quantity, and nutrient dynamics. We hypothesized that these biogeochemical changes would also affect the soil microbial community and the extracellular enzymes responsible for carbon and nutrient mineralization. Across three sites differing in substrate texture and a...
متن کاملCascading effects of belowground predators on plant communities are density‐dependent
Soil food webs comprise a multitude of trophic interactions that can affect the composition and productivity of plant communities. Belowground predators feeding on microbial grazers like Collembola could decelerate nutrient mineralization by reducing microbial turnover in the soil, which in turn could negatively influence plant growth. However, empirical evidences for the ecological significanc...
متن کامل