Seventy years of different management treatments have produced significant differences in runoff, erosion, and ponded infiltration rate in a winter wheat (Triticum aestivum L.)–summer fallow experiment in OR, USA. We tested the hypothesis that differences in infiltration are due to changes in soil structure related to treatment-induced biological changes. All plots received the same tillage (pl...

Soil microbes are highly diverse and control most soil biogeochemical reactions. We examined how microbial functional genes and biogeochemical pools responded to the altered chemical inputs accompanying land use change. We examined paired native grasslands and adjacent Eucalyptus plantations (previously grassland) in Uruguay, a region that lacked forests before European settlement. Along with m...

Northwestern Alaska has been warming (0.3°C/yr) since the early 1990s. Ecotonal (treeline) Arctic ecosystems are expected to exhibit the effects of climate change earliest. High-latitude terrestrial ecosystems contain from 30 to 45 percent of the global organic-C pool. Soil warming may enhance release of CO2 and CH4, soil N mineralization, and the production and export of dissolved organic C an...

Incorporation of plant residues in soil affects N and C content and dynamics. This studydetermined the effects of short-term alternative rice (Oryza sativa L.) residue management on Nmineralization and uptake by rice. Pot and laboratory incubation experiments were established byincorporating 15N-labeled rice straw and rice straw compost in paddy soil. The 15N recovered by riceaveraged 16.6%; mo...

Soils on the Mormon Trail have been compacted for over 150 years. Bulk density, carbon, and nitrogen samples were taken in 5-cm increments to 20 cm. Bulk density was determined using rings of known volume; total carbon and nitrogen with a LECO CHN-600. Total above ground biomass (AGB) samples were collected by clipping vegetation within a 0.25 m2 frame and were analyzed for carbon. Statistical ...

The long-term response of total soil organic carbon pools (‘total SOC’, i.e. soil and dead wood) to different harvesting scenarios in even-aged northern hardwood forest stands was evaluated using two soil carbon models, CENTURY and YASSO, that were calibrated with forest plot empirical data in the Green Mountains of Vermont. Overall, 13 different harvesting scenarios that included four levels o...

The maintenance of low availability of mineral N in heath soils is thought to be a key factor for the stability of heathland ecosystems. We investigated the turnover of NH4 ‡ and NO3 ÿ in the organic surface layer of soils from a Danish heathland using N isotope techniques in laboratory incubations. The soils were sampled under intact and dead Calluna vegetation. The dead Calluna vegetation had...

The coniferous forest tree Douglas-fir (Pseudotsuga menziesii) is native to the pacific North America, and is increasingly planted in temperate regions worldwide. Nitrogen (N) metabolism is of great importance for growth, resistance and resilience of trees. In the present study, foliar N metabolism of adult trees of three coastal and one interior provenance of Douglas-fir grown at two common ga...

This study was aimed to assess the decomposition temperature sensitivity (Q10) of C fractions cycling from yearly through decades’ and up to centennial timescales using a data assimilation approach. A three-pool C-cycling model was optimally fitted with previously-published data from a 588-day long soil incubation experiment conducted at two temperatures (25 and 35 C) for 12 soils collected fro...