With the increased occurrence of climate extremes, there is an urgent need to better understand how management strategies affect the capacity of the soil microbial community to maintain its ecosystem functions (e.g. nutrient cycling). To address this issue, intact monoliths were extracted from conventional and ecological managed grasslands in three countries across Europe and exposed under common air condition (temperature and moisture) to one of three altered rain regimes (dry, wet and intermittent wet/dry) as compared to a normal regime. Subsequently, we compared the resistance and recovery of the soil microbial biomass, potential enzyme activities and community composition. The microbial community composition differed with soil management and rain regimes. Soil microbial biomass increased from the wetter to the dryer rain regime, paralleling an increase of available carbon and nutrients, suggesting low sensitivity to soil moisture reduction but nutritional limitations of soil microbes. Conversely, enzyme activities decreased with all altered rain regimes. Resistance and recovery (considering absolute distance between normal and altered rain regime) of the microbial communities depended on soil management. Conventional‐intensive management showed higher resistance of two fundamental properties for nutrient cycling (i.e. bacterial biomass and extracellular enzyme activities) yet associated with more important changes in microbial community composition. This suggests an internal community reorganization promoting biomass and activity resistance. Conversely, under ecological management bacterial biomass and enzyme activities showed better recovery capacity, whereas no or very low recovery of these properties was observed under conventional management. These management effects were consistent across the three altered rain regimes investigated, indicating common factors controlling microbial communities’ response to different climate‐related stresses. Synthesis and applications. Our study provides experimental evidence for an important trade‐off for agroecosystem management between (a) stabilizing nutrient cycling potential during an altered rain regime period at the expense of very low recovery capacity and potential long‐term effect (conventional sites) and (b) promoting the capacity of the microbial community to recover its functional potential after the end of the stress (ecological sites). Thus, management based on ecologically sound principles may be the best option to sustain long‐term soil functioning under climate change.

Projected climate change and rainfall variability will affect soil microbial communities, biogeochemical cycling and agriculture. Nitrogen (N) is the most limiting nutrient in agroecosystems and its cycling and availability is highly dependent on microbial driven processes. In agroecosystems, hydrolysis of organic nitrogen (N) is an important step in controlling soil N availability. We analyzed the effect of management (ecological intensive vs. conventional intensive) on N-cycling processes and involved microbial communities under climate change-induced rain regimes. Terrestrial model ecosystems originating from agroecosystems across Europe were subjected to four different rain regimes for 263 days. Using structural equation modelling we identified direct impacts of rain regimes on N-cycling processes, whereas N-related microbial communities were more resistant. In addition to rain regimes, management indirectly affected N-cycling processes via modifications of N-related microbial community composition. Ecological intensive management promoted a beneficial N-related microbial community composition involved in N-cycling processes under climate change-induced rain regimes. Exploratory analyses identified phosphorus-associated litter properties as possible drivers for the observed management effects on N-related microbial community composition. This work provides novel insights into mechanisms controlling agro-ecosystem functioning under climate change. As in many terrestrial ecosystems, nitrogen (N) is the most limiting nutrient for plant growth in agroecosystems 1-3. The last century has been characterized by a considerable increase of N inputs in agricultural soils 4-7 , mostly in mineral form (NH 4 +), making plant growth less dependent on microbial N provisioning. However, the increased amount of reactive N in the environment has severe environmental and human health consequences 7 .

Organic farming (OF) enhances top soil organic carbon (SOC) stocks in croplands compared with conventional farming (CF), which can contribute to sequester C. As farming system differences in the amount of C inputs to soil (e.g. fertilization and crop residues) are not enough to explain such increase, shifts in crop residue traits important for soil C losses such as litter decomposition may also play a role. To assess whether crop residue (leaf and root) traits determined SOC sequestration responses to OF, we coupled a global meta‐analysis with field measurements across a European‐wide network of sites. In the meta‐analysis, we related crop species averages of leaf N, leaf‐dry matter content, fine‐root C and N, with SOC stocks and sequestration responses in OF vs. CF. Across six European sites, we measured the management‐induced changes in SOC stocks and leaf litter traits after long‐term ecological intensive (e.g. OF) vs. CF comparisons. Our global meta‐analysis showed that the positive OF‐effects on soil respiration, SOC stocks, and SOC sequestration rates were significant even in organic farms with low manure application rates. Although fertilization intensity was the main driver of OF‐effects on SOC, leaf and root N concentrations also played a significant role. Across the six European sites, changes towards higher leaf litter N in CF also promoted lower SOC stocks. Our results highlight that crop species displaying traits indicative of resource‐acquisitive strategies (e.g. high leaf and root N) increase the difference in SOC between OF and CF. Indeed, changes towards higher crop residue decomposability was related with decreased SOC stocks under CF across European sites. Synthesis and applications. Our study emphasizes that, with management, changes in crop residue traits contribute to the positive effects of organic farming (OF) on soil carbon sequestration. These results provide a clear message to land managers: the choice of crop species, and more importantly their functional traits (e.g. leave and root nitrogen), should be considered in addition to management practices and climate, when evaluating the potential of OF for climate change mitigation.

No abstract

No abstract

gered species (Beissinger & Westphal, 1998). Although it is a good tool in population studies, spatial distribution is dependent of several variables that determine the suitability of sites for the establishment of individuals in the environment, such as sun exposure, soil or air humidity, altitude, availability of food and shelter, and sites for nesting and breeding (Soares & Schoereder, 2001; Van Gils & Vanderwoude, 2012).

Espécies de Diptera, principalmente as moscas, tem se mostrado como potenciais bioindicadores para mudanças ambientais. Para captura destes animais, há diferentes métodos, incluindo as armadilhas com atrativos alimentares. Neste estudo, para avaliar a eficiência de armadilhas na captura de moscas usando isca de melaço de cana-de-açúcar, foram avaliados os parâmetros ecológicos: abundância, riqueza e composição de espécies de moscas, comparando diferentes períodos de exposição das armadilhas em campo: 24, 48, 72 e 96h. A riqueza e abundância apresentaram mudança significativa em relação ao tempo de exposição da isca, tendo se estabilizado após 48h, e a composição diferiu entre o primeiro dia (24h) e os demais (48, 72, 96h). Effect of Aging Bait for Catching Flies (Diptera: Brachycera) in a Caatinga Area Abstract. Diptera species, especially flies, has shown potential as bioindicators for environmental changes. There are different methods to capture these animals, including traps with food baits. In this study, we assess the efficiency of traps for catching flies using bait of cane sugar molasses, analyzing the ecological parameters: abundance, species richness and species composition of flies during different periods of exposure of the traps in the field: 24, 48, 72 and 96h. Species richness and abundance showed significant change with respect to exposure time in the field, with stabilization after 48h, and species composition differed between the first and the other days.

No abstract