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A pulse of respiration is induced by rewetting dry soil. Here we study the microbial responses underlying this pulse of respiration when rewetting soil dried for 4-days or 1-year. In the 4-days dried soil, respiration increased to a maximum rate immediately upon rewetting after which it decreased exponentially. In the 1-year dried soil, respiration also increased immediately, but then remained hig

An expectation in soil ecology is that a microbial communities' fungal:bacterial dominance indicates both its response to environmental change and its impact on ecosystem function. We review a selection of the increasing body of literature on this subject and assess the relevance of its expectations by examining the methods used to determine, the impact of environmental factors on, and the expecte

Centuries of artificial selection have dramatically improved the yield of human agriculture; however, strong directional selection also occurs in natural symbiotic interactions. Fungus-growing attine ants cultivate basidiomycete fungi for food. One cultivar lineage has evolved inflated hyphal tips (gongylidia) that grow in bundles called staphylae, to specifically feed the ants. Here we show exten

Bacterial and fungal growth rate measurements are sensitive variables to detect changes in environmental conditions. However, while methods to assess the species composition and biomass of fungi and bacteria has made much progress, information about growth rates remains surprisingly rudimentary. We review the recent history of approaches to assess bacterial and fungal growth rates, leading up to c

The clover seed weevils Apion fulvipes Geoffroy, 1785 and Apion trifolii L., 1768 (Coleoptera: Apionidae) cause major losses to seed production of white clover (Trifolium repens L.) and red clover (Trifolium pratense L.), respectively. Clover is important as animal forage and an alternative to inorganic fertilizers. Because clover is mainly pollinated by bees, the use of insecticides in management

Increasing nitrogen(N) deposition due to anthropogenic activities has become a significant global change threat to N-poor terrestrial ecosystems. We compared bacterial growth and nutrients limiting bacterial growth in one of the longest running experiments on increasing N-deposition to a temperate forest, the Chronic Nitrogen Amendment Study at Harvard Forest, USA. Soil samples were collected in f

Under chronically elevated N deposition, N retention mainly occur at high soil C-to-N ratio. This may be mediated through soil microbes, such as ectomycorrhizal (EM) fungi, saprotrophic fungi and bacteria, and the aim of this study was to evaluate the relationship between soil microbes and forest floor C-to-N ratios. Soil samples from 33 Norway spruce (Picea abies (L.) H. Karst) forests in Denmark

The influence of soil pH on the phospholipid fatty acid (PLFA) composition of the microbial community was investigated along the Hoosfield acid strip, Rothamsted Research, UK - a uniform pH gradient between pH 8.3 and 4.5. The influence of soil pH on the total concentration of PLFAs was not significant, while biomass estimated using substrate induced respiration decreased by about 25%. However, th

Microbial decomposition of soil organic matter (SOM) is the source of most of the terrestrial carbon dioxide emission. Consequently, our ability to predict how climate warming will affect the global carbon (C) budget relies on our understanding of the temperature relationship and adaptability of microbial processes. We exposed soil microcosms to temperatures between 0 and 54 degrees C for 2 months

Boreal forest soils function as a terrestrial net sink in the global carbon cycle. The prevailing dogma has focused on aboveground plant litter as a principal source of soil organic matter. Using C-14 bomb-carbon modeling, we show that 50 to 70% of stored carbon in a chronosequence of boreal forested islands derives from roots and root-associated microorganisms. Fungal biomarkers indicate impaired

Foliose lichens with cyanobacterial bionts (bipartite and tripartite) form a distinct assemblage of epiphytes strongly associated with humid microclimatic conditions in inland British Columbia. Previous research showed that these cyano- and cephalolichen communities are disproportionately abundant and species-rich on conifer saplings beneath Populus compared to beneath other tree species. More rev

Mycorrhizal fungi constitute a considerable sink for carbon in most ecosystems. This carbon is used for building extensive mycelial networks in the soil as well as for metabolic activity related to nutrient uptake. A number of methods have been developed recently to quantify production, standing biomass and turnover of extramatrical mycorrhizal mycelia (EMM) in the field. These methods include min

Archaea are ubiquitous in forest soils, but little is known about the factors regulating their abundance and distribution. Low molecular weight organic compounds represent an important energy source for archaea in marine environments, and it is reasonable to suspect that archaeal abundance is dependent on such compounds in soils as well, represented by, for example, plant and fungal exudates. To t

A more detailed mechanistic understanding of how low molecular weight (MW) carbon (C) substrates are mineralized within the rhizosphere by soil microbial communities is crucial to accurately model terrestrial C fluxes. Currently, most experiments regarding soil C dynamics are conducted ex-situ (laboratory) and can fail to account for key variables (e.g. temperature and soil water content) which va

Background: Array comparative genomic hybridization (aCGH) is commonly used to screen different types of genetic variation in humans and model species. Here, we performed aCGH using an oligonucleotide gene-expression array for a non-model species, the intertidal snail Littorina saxatilis. First, we tested what types of genetic variation can be detected by this method using direct re-sequencing and

Rewetting a dry soil can result in two response patterns of bacterial growth and respiration. In type 1, bacterial growth starts to increase linearly immediately upon rewetting and respiration rates are highest immediately upon rewetting. In type 2, bacterial growth starts to increase exponentially after a lag period with a secondary increase in respiration occurring at the start of the exponentia

To estimate the production of external ectomycorrhizal mycelia (EMM) in Norway spruce forests with varying nitrogen (N) and phosphorus (P) levels, and to relate this to the N retention capacity of ectomycorrhizal fungi (EMF) and N leaching. Seasonal changes in EMF production (in ingrowth mesh bags) and soil water N (in suction lysimeters) were analyzed after fertilization with N or N combined with