In Alaska, an outbreak of spruce beetles (Dendroctonus rufipennis) recently infested over one million hectares of spruce (Picea spp.) forest. As a result, land management agencies have applied different treatments to infested forests to minimize fire hazard and economic loss and facilitate forest regeneration. In this study we investigated the […]
1. The effects of global change on below-ground processes of the nitrogen (N) cycle have repercussions for plant communities, productivity and trace gas effluxes. However, the interacting effects of different components of global change on nitrification or denitrification have rarely been studied in situ. 2. We measured responses of nitrifying enzyme activity […]
[1] Measuring the stable isotope composition of nitrous oxide (N2O) evolved from soil could improve our understanding of the relative contributions of the main microbial processes (nitrification and denitrification) responsible for N2O formation in soil. However, interpretation of the isotopic data in N2O is complicated by the lack of knowledge of […]
Free air carbon dioxide enrichment (FACE) and open top chamber (OTC) studies are valuable tools for evaluating the impact of elevated atmospheric CO2 on nutrient cycling in terrestrial ecosystems. Using meta-analytic techniques, we summarized the results of 117 studies on plant biomass production, soil organic matter dynamics and biological N2 […]
Amidst a network of tunnels and pores, soil organisms recycle carbon and nutrients. They mix plant litter and detritus, causing changes in soil structure that can ultimately influence the amount of water and oxygen available for plant roots. They are also eaten by aboveground predators, providing direct connections between below-and […]
We report the first simultaneous measurements of δ15N and δ13C of DNA extracted from surface soils. The isotopic composition of DNA differed significantly among nine different soils. The δ13C and δ15N of DNA was correlated with δ13C and δ15N of soil, respectively, suggesting that the isotopic composition of DNA is […]
Organisms acquire some elements from the environment with ease. Diffusion alone often provides enough carbon dioxide, oxygen and water. But getting other elements requires more effort, spurring unique evolutionary adaptations: instead of taking up nutrients from the soil, some plants in acidic bogs trap insects to obtain nitrogen and phosphorus […]
1. Despite the importance of microorganisms for leaf litter decomposition in streams, little is known about which factors affect community composition of bacterial and fungal communities. Standard morphological techniques probably underestimate microbial diversity. 2. We used terminal restriction fragment length polymorphisms of the ITS regions for fungi, and the 16S […]
Flow diversion and invasive species are two major threats to freshwater ecosystems, threats that restoration efforts attempt to redress. Yet, few restoration projects monitor whether removal of these threats improve target charac- teristics of the ecosystem. Fewer still have an appropriate experimental design from which causal inferences can be drawn […]
Changing climate and a legacy of fire-exclusion have increased the probability of high-severity wildfire, leading to an increased risk of forest carbon loss in ponderosa pine forests in the southwestern USA. Efforts to reduce high-severity fire risk through forest thinning and prescribed burning require both the removal and emission of […]