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1. Restoration ecology is moving towards designing restoration actions to maximize ecosystem services (ES). Such restoration actions require planning at large spatial scales, as these are often more meaningful for ecosystem functioning and ES supply. As economic resources to undertake ecological restoration at large scales are scarce, prioritizing sites to enhance multiple ES supply is critical. 2. Our study presents an index, the Relative Aggregated Value of ES (RAVES), to prioritize sites for ecological restoration based on the assessment of multiple ES. We tested the spatial heterogeneity of ES to identify the relevant scale to managing ES and to applying the RAVES index using a local case study. We also used the RAVES index to compare three alternative restoration scenarios to enhance ES based on the availability of socio-economic resources. 3. The highest RAVES values were found in areas with natural vegetation and in gorges with riparian forests. The lowest RAVES values were found in crop fields, steep slopes, and river stretches without riparian forest. 4. The multi-scale spatial analysis indicated that most ES showed significant heterogeneity at multiple spatial scales, especially at broad (20–30 km) and very broad (40–50 km) scales. However, at spatial scales smaller than 2 km, only biological control showed significant heterogeneity. 5. The optimal socio-economic conditions to enhance ES supply were met in a scenario where both private and public land and economic funds were available to implement ecological restoration. As most areas with low RAVES were in private lands, even with scarce economic funds restoration of private lands would result in a large increase of RAVES. 6. Synthesis and applications. The RAVES index is a practical tool to hierarchically prioritize sites for ecological restoration across large spatial scales. When linked to scenario analysis, the RAVES index can also be used to identify optimal management scenarios. By linking ES assess

Soil micromorphology in thin section and near infrared reflectance spectroscopy (NIRS) are useful techniques for assessing the participation of soil macrofauna in the formation of aggregates and soil structure. The purpose of this study was to use micromorphological analysis and NIRS techniques to assess the role of soil fauna in the recovery of soil aggregates and in the modification of soil microstructure in a chronosequence of rehabilitated areas at Cerrejon coal mine (La Guajira, Colombia). 64 soil samples were taken from rehabilitated areas (from 1 to 20 years ago) and from natural dry tropical forests Soil macroaggregates were subdivided into three categories: biogenic (BA), physical (PA), and non-aggregated soil (NAS). 32 samples were used for NIRS analysis, while ten thin sections of resin-impregnated soil blocks were micromorphologically analyzed. Principal component analysis of NIRS spectra showed a clear separation between BA, PA, and NAS. Likewise, an increase in BA was observed in the intermediate and advanced stages of rehabilitation. Respect to the micromorphological features, there was a clear change from a matrix of silt-sized quartz, unaccomodated peds, and unstructured materials with non-existent biogenic activity at the 2-year site to the formation of consolidated aggregates, more homogenized soil and increased biological activity at the 20-year site. Soil biological activity, principally the footprint of macrofauna, was recognized using the two techniques as well as at both the micro- and macro-morphology scales. These results reveal how the rehabilitation program being undertaken at Cerrejón mine is promoting the soil macrofauna population and associated bioturbation.

1. Atmospheric nitrogen (N) deposition and climate warming are two major components of global change that drive species richness and composition in plant communities. However, their combined effects have been insufficiently investigated across large spatial and temporal scales particularly in high-elevation, nutrient-limited ecosystems. 2. We examine whether and how N deposition and climate warming have altered the plant richness and the composition of subalpine semi-natural, extensively grazed grasslands of the Pyrenees, using two complementary approaches: (i) analysis of 553 releves to explore vegetation changes across large ecological gradients including temperature and N deposition (spatial approach) and (ii) a re-sampling of a subset of 40 sites among the 553 sites to assess temporal changes over the past decades (temporal approach). 3. Both approaches showed that the vascular plant species richness increased when temperature and cumulative N deposition increase, shifting the species composition towards more thermophilic and eutrophic communities. 4. Synthesis. We hypothesize that the release from abiotic constraints (milder temperature and higher nitrogen availability) due to global changes and long-standing extensive grazing counteracting the negative effects of nitrogen deposition have been responsible for the diversity and compositional changes of plant communities over the last decades in the Pyrenees. Thus, in contrast with other grasslands, high-elevation grazed grasslands may increase in species diversity with nitrogen deposition under climate warming.

Soil organic matter (SOM) is key to maintaining soil fertility, mitigating climate change, combatting land degradation, and conserving above- and below-ground biodiversity and associated soil processes and ecosystem services. In order to derive management options for maintaining these essential services provided by soils, policy makers depend on robust, predictive models identifying key drivers of SOM dynamics. Existing SOM models and suggested guidelines for future SOM modelling are defined mostly in terms of plant residue quality and input and microbial decomposition, overlooking the significant regulation provided by soil fauna. The fauna controls almost any aspect of organic matter turnover, foremost by regulating the activity and functional composition of soil microorganisms and their physical–chemical connectivity with soil organic matter. We demonstrate a very strong impact of soil animals on carbon turnover, increasing or decreasing it by several dozen percent, sometimes even turning C sinks into C sources or vice versa. This is demonstrated not only for earthworms and other larger invertebrates but also for smaller fauna such as Collembola. We suggest that inclusion of soil animal activities (plant residue consumption and bioturbation altering the formation, depth, hydraulic properties and physical heterogeneity of soils) can fundamentally affect the predictive outcome of SOM models. Understanding direct and indirect impacts of soil fauna on nutrient availability, carbon sequestration, greenhouse gas emissions and plant growth is key to the understanding of SOM dynamics in the context of global carbon cycling models. We argue that explicit consideration of soil fauna is essential to make realistic modelling predictions on SOM dynamics and to detect expected non-linear responses of SOM dynamics to global change. We present a decision framework, to be further developed through the activities of KEYSOM, a European COST Action, for when mechanistic SOM models i

[EN] The Ordesa and Monte Perdido National Park and the Pyrenean Institute of Ecology (CSIC) recently joined the Spanish LTER network. As part of our strategy to understand recent changes in this protected area, we are carrying out a number of projects to evaluate changes at different spatio-temporal scales, using a variety of methods and approaches. We highlight here some of the most consolidated ones: long-term reconstructions from sedimentary lake records and cave speleothemes, the dynamics of one of the few active Iberian glaciers, the physico-chemical components of alpine streams, springs and lakes, the fingerprint of climatic change from ancient trees, changes in the composition and structure of biodiversity of alpine communities, natural and man-made grasslands at different altitudes, and the treeline, and population dynamics of endangered species or habitat indicators. The ecological monitoring shows that changes in both climate and land use, are having a strong influence in the physiognomy and structure of some of the most iconic and abundant habitats in the National Park. However, we found an important spatial variability in some processes, and also that others do not fit the established paradigms. The integration of partial results obtained from different methodologies and approaches diminishes the importance of each perception separately, helps to evaluate current changes in a long-term framework (geological scale), and will serve to validate the forecasts when modeling future environmental scenarios., [ES] Los espacios protegidos, por el hecho de albergar una gran geo-biodiversidad y asegurar una baja intervención humana, constituyen lugares muy adecuados para el seguimiento de organismos y procesos a escala ecológica, así como para la obtención de series temporales largas a escala geológica. En el marco de la red LTER-España, el Parque Nacional de Ordesa y Monte Perdido (PNOMP) y el Instituto Pirenaico de Ecología-CSIC están impulsando estudios para la detección de cambios a distintas escalas mediante variados métodos y aproximaciones. Destacamos aquí los más consolidados, entre los que se encuentran los análisis de registros de sedimentos en lagos, espeleotemas en cuevas, la dinámica de uno de los pocos glaciares activos de la Península ibérica, el análisis físico-químico de aguas corrientes e ibones de alta montaña, el registro del cambio climático actual en árboles longevos, la afección que éste ejerce sobre masas actuales de pinos en el límite superior del bosque y de abetales en zonas húmedas, la matorralización de algunos pastos y los procesos mecanicistas que subyacen, la reorganización de la diversidad florística en pastos tras el abandono paulatino o drástico de la ganadería, la biodiversidad de las comunidades alpinas y la dinámica poblacional de especies amenazadas o indicadoras de hábitats o de motores de cambio global. Los seguimientos ecológicos actuales muestran que tanto el cambio climático como el de usos del suelo están teniendo una considerable trascendencia en la fisionomía y la estructura de algunos de los ambientes más icónicos y frecuentes del parque (deterioro del glaciar, termofilización de la flora en cumbres alpinas, densificación del bosque en su límite superior, pérdida de productividad en algunos pastos supraforestales, etc.). También sugieren una importante variabilidad espacial en los procesos (por ej. en el PNOMP conviven pastos matorralizados y pastos muy estables), y evidencian que los cambios observados no siempre siguen los p

The authors discuss and demonstrate the growth of InN surface quantum dots on a high-In-content In0.73Ga0.27N layer, directly on a Si(111) substrate by plasma-assisted molecular beam epitaxy. Atomic force microscopy and transmission electron microscopy reveal uniformly distributed quantum dots with diameters of 10–40 nm, heights of 2–4 nm, and a relatively low density of ∼7 × 109 cm−2. A thin InN wetting layer below the quantum dots proves the Stranski-Krastanov growth mode. Near-field scanning optical microscopy shows distinct and spatially well localized near-infrared emission from single surface quantum dots. This holds promise for future telecommunication and sensing devices.

Alteration in vitamin D metabolism has been growing in importance until be considered a health public problem. Increasingly are more frequent the etiologies related to vitamin D deficiency and the long-term effects, which making necessary to know not only the molecular basis of vitamin D metabolism, with special attention to the participation of cytochrome p450 family enzymes, but also the description of the metabolic pathways, interaction with the specific receptor, genomic and non-genomic actions, results in bone metabolism and extraskeletal actions. In addition, the direct action of antiepileptic drugs on cytochrome P450 enzymes and their negative effects on vitamin D levels and bone metabolism. This review aims to provide the basis that allow to extrapolate these concepts to clinical practice and identify patients at risk of vitamin D deficiency due to the chronically use antiepileptic drugs that require therapeutic conduct. It should be remembered that currently there is no universal protocol on clinical monitoring of these patients even with the improvement in access to diagnostic resources., La alteración en el metabolismo de la vitamina D ha ido creciendo en importancia hasta considerarse un problema de salud pública. Cada vez son más frecuentes las etiologías relacionadas al déficit de la vitamina D y con consecuencias a largo plazo, lo que hace necesario conocer no sólo las bases moleculares del metabolismo de la vitamina D, con especial atención en la participación de las enzimas de la familia del citocromo P450, sino la descripción de las vías metabólicas, la interacción con el receptor específico, las acciones genómicas y no genómicas, sus resultados en el metabolismo óseo y las acciones extra esqueléticas. Además, la acción directa de los antiepilépticos sobre las enzimas de la citocromo P450 y su efecto negativo sobre los niveles de la vitamina D y el metabolismo óseo. Esta revisión pretende brindar las bases que permitan extrapolar estos conceptos a la práctica clínica e identificar los pacientes con riesgo de hipovitaminosis D debido al uso crónico de antiepilépticos que requieren una conducta terapéutica. Es necesario tener presente que en la actualidad no hay un protocolo clínico universal sobre el seguimiento de estos pacientes incluso con la mejoría en el acceso a recursos diagnósticos.

A detailed understanding of the study area is essential to achieve key information and optimize the monitoring, analysis, and evaluation of water quality of natural ecosystems that have been highly transformed into agricultural areas. Using classification techniques like the hierarchical cluster analysis (CA) and partial triadic analysis (PTA), we assessed the sources of water pollution and the seasonal influence of human activities in water composition in a river basin from northeastern Spain. The results suggested that a strong connection existed between water quality and the seasonality of the human activities. The CA showed the spatial relationship between water chemistry and the adjacent land uses. The PTA associated the analyzed variables to their pollutant source. Electrical conductivity (EC), Cl−, SO4 2−–S, Na+, and Mg2+ ions were related with agricultural sources, whereas NH4 +–N, PT, and PO4 3−–P were linked with urban polluted sites. Concentration of NO3ˉ–N was associated with urban land use. Differences in water composition according to the irrigation intensity were also found during the irrigation season. The statistical tools used in this work, especially the PTA, allowed us to jointly analyze the spatial and seasonal components of water pollutant trends. We obtained a more comprehensive knowledge of water quality patterns in the study area, which will be essential when taking measures to minimize the effects of water pollution.

Multivariate techniques for two-dimensional data matrices are normally used in water quality studies. However, if the temporal dimension is included in the analysis, other statistical techniques are recommended. In this study, partial triadic analysis (PTA) was used to investigate the spatial and temporal variability in water-quality variables sampled in a northeastern Spain river basin. The results highlight the spatiality of the physical and chemical properties of water at different sites along a river over one year. PTA allowed us to clearly identify the presence of a stable spatial structure that was common to all sampling dates across the entire catchment. Variables such as electrical conductivity (EC) and Na⁺ and Clˉ ions were associated with agricultural sources, whereas total dissolved nitrogen (TDN), NH₄⁺-N concentrations and NO₂ˉ-N concentrations were linked to polluted urban sites; differences were observed between irrigated and non-irrigated periods. The concentration of NO₃ˉ-N was associated with both agricultural and urban land uses. Variables associated with urban and agricultural pollution sources were highly influenced by the seasonality of different activities conducted in the study area. In analyzing the impact of land use and fertilization management on water runoff and effluents, powerful statistical tools that can properly identify the causes of pollution in watersheds are important. PTA can efficiently summarize site-specific water chemistry patterns in an applied setting for land- and water-monitoring schemes at the landscape level. The method is recommended for land-use decision-making processes to reduce harmful environmental effects and promote sustainable watershed management.

Paciente de 13 años de edad sin antecedentes médico-quirúrgicos de interés. Acude por hipermovilidad en primer dedo de la mano izquierdacon antecedente de fractura de la base del primer metacarpiano de cuatro meses de evolución, tratada de forma conservadora, con férula antebraquial con extensión al primer dedo, durante tres semanas.

La patología postraumática de la articulación radiocubital distal, es un problema frecuente y de dificil tratamiento, sobre todo en aquellos casos que pasan desapercibidos inicialmente y se cronifican.A continuación presentamos una paciente con una inestabilidad crónica postraumática de la articulación radiocubital distal tratada quirúrgicamente mediante una técnica de reconstrucción ligamentosa de forma satisfactoria.

[Background] Studying the drivers and determinants of species, population and community spatial patterns is central to ecology. The observed structure of community assemblages is the result of deterministic abiotic (environmental constraints) and biotic factors (positive and negative species interactions), as well as stochastic colonization events (historical contingency). We analyzed the role of multi-scale spatial component of soil environmental variability in structuring earthworm assemblages in a gallery forest from the Colombian “Llanos”. We aimed to disentangle the spatial scales at which species assemblages are structured and determine whether these scales matched those expressed by soil environmental variables. We also tested the hypothesis of the “single tree effect” by exploring the spatial relationships between root-related variables and soil nutrient and physical variables in structuring earthworm assemblages. Multivariate ordination techniques and spatially explicit tools were used, namely cross-correlograms, Principal Coordinates of Neighbor Matrices (PCNM) and variation partitioning analyses., [Results] The relationship between the spatial organization of earthworm assemblages and soil environmental parameters revealed explicitly multi-scale responses. The soil environmental variables that explained nested population structures across the multi-spatial scale gradient differed for earthworms and assemblages at the very-fine- (<10 m) to medium-scale (10–20 m). The root traits were correlated with areas of high soil nutrient contents at a depth of 0–5 cm. Information on the scales of PCNM variables was obtained using variogram modeling. Based on the size of the plot, the PCNM variables were arbitrarily allocated to medium (>30 m), fine (10–20 m) and very fine scales (<10 m). Variation partitioning analysis revealed that the soil environmental variability explained from less than 1% to as much as 48% of the observed earthworm spatial variation., [Conclusions] A large proportion of the spatial variation did not depend on the soil environmental variability for certain species. This finding could indicate the influence of contagious biotic interactions, stochastic factors, or unmeasured relevant soil environmental variables.

In alpine areas, shifts in traditional grazing activities are globally affecting ecosystem properties and rural livelihoods. The ongoing decrease in extensive husbandry, with a decline in sheep numbers and a relative increase in cattle stocking rates, has resulted in the abandonment of large alpine grazing areas. This pastoral change has been recently associated with increased disturbances of wild boar (Sus scrofa), mainly within cattle-stocked ranges. In turn, cattle areas favor earthworm communities, a preferred trophic resource for wild boars in mountain environments. However, it is unknown whether wild boar disturbances, together with grazing activities, can affect earthworm communities. Our aim is to analyze the abundance, richness and ecological categories of earthworms and soil parameters (soil C and N concentrations, moisture, and C:N ratio) in relation to the occurrence of wild boar disturbances and grazing activities at different stocking pressures. We sampled two different grazing scenarios differing in the distribution of cattle along a grazing gradient, which was represented by three levels of stocking pressure (high, intermediate and low). Our results showed a complex effect of grazing activities and disturbances on the abundance and richness of earthworms, along with variations in C:N ratio and soil moisture, especially with increasing cattle presence. At high-stocking pressures differences in earthworm abundance and richness between disturbed and undisturbed areas were limited, whereas at intermediate-stocking pressures earthworms were favored by wild boar disturbances. Ecological categories of earthworms responded differently; endogeic species were the most affected by grazing pressures and wild boar rooting, with highest occurrence at high-stocking pressures and within boar disturbed areas. In sum, pastoral use and soil disturbances affected earthworm community structure and composition in complex ways. These results indicate an interaction of proc

Biolog EcoPlates™ can be used to measure the carbon substrate utilisation patterns of microbial communities. This method results in a community-level physiological profile (CLPP), which yields a very large amount of data that may be difficult to interpret. In this work, we explore a combination of statistical techniques (particularly the use of generalised additive models [GAMs]) to improve the exploitation of CLPP data. The strength of GAMs lies in their ability to address highly non-linear relationships between the response and the set of explanatory variables. We studied the impact of earthworms (Aporrectodea caliginosa Savigny 1826) and cadmium (Cd) on the CLPP of soil bacteria. The results indicated that both Cd and earthworms modified the CLPP. GAMs were used to assess time-course changes in the diversity of substrate utilisation (DSU) using the Shannon-Wiener index. GAMs revealed significant differences for all treatments (compared to control -S-). The Cd exposed microbial community presented very high metabolic capacities on a few substrata, resulting in an initial acute decrease of DSU (i.e. intense utilization of a few carbon substrata). After 54 h, and over the next 43 h the increase of the DSU suggest that other taxa, less dominant, reached high numbers in the wells containing sources that are less suitable for the Cd-tolerant taxa. Earthworms were a much more determining factor in explaining time course changes in DSU than Cd. Accordingly, Ew and EwCd soils presented similar trends, regardless the presence of Cd. Moreover, both treatments presented similar number of bacteria and higher than Cd-treated soils. This experimental approach, based on the use of DSU and GAMs allowed for a global and statistically relevant interpretation of the changes in carbon source utilisation, highlighting the key role of earthworms on the protection of microbial communities against the Cd.

Many dryland areas are being converted into intensively managed irrigation crops, what can disrupt the hydrological regime, degrade soil and water quality, enhance siltation, erosion and bank instability, and affect biological communities. Still, the impacts of irrigation schemes on the functioning of terrestrial and aquatic ecosystems are poorly understood. Here we assess the effects of irrigation agriculture on breakdown of coarse organic matter in soil and water. We measured breakdown rates of alder and holm oak leaves, and of poplar sticks in terrestrial and aquatic sites following a gradient of increasing irrigation agriculture in a semi-arid Mediterranean basin transformed into irrigation agriculture in 50% of its surface. Spatial patterns of stick breakdown paralleled those of leaf breakdown. In soil, stick breakdown rates were extremely low in non-irrigated sites (0.0001-0.0003day-1), and increased with the intensity of agriculture (0.0018-0.0044day-1). In water, stick breakdown rates ranged from 0.0005 to 0.001day-1, and increased with the area of the basin subject to irrigation agriculture. Results showed that irrigation agriculture affects functioning of both terrestrial and aquatic ecosystems, accelerating decomposition of organic matter, especially in soil. These changes can have important consequences for global carbon budgets. © 2013 Elsevier B.V.

[EN] Terrestrial invertebrate species play a dominant role in the trophic dynamics of agricultural ecosystems. Subtle changes in the composition of communities and species interactions at different trophic levels, and role of ecosystem engineers can dramatically modify the effects of invertebrates on plant productivity in agricultural systems. The effect of climate change on relevant invertebrates in agricultural systems, and their potential to adapt or move is discussed. All terrestrial systems (including forestry and pasture) are considered, although the main focus is on crop production systems. Our treatise centres on whole organisms (as opposed to genetic information from invertebrates) that play key roles in agricultural systems.Westart with an overview of current thinking on how climate change may affect invertebrates. Then, recognizing the great invertebrate biodiversity associated with agro-ecosystems, the review focuses on three key groups - soil invertebrates, biological control agents and pollinators. A variety of research gaps became apparent during the course of our review. Specific conclusions regarding the impact of climate change on particular elements of invertebrate genetic resources in agriculture are not possible yet. Existing evidence suggests that three general assumptions can be made. First, it is probable that climate change will disrupt to varying degrees the role and use of invertebrates in agriculture, especially sustainable agriculture, even though the precise nature of the disruptions is not yet known. Second, without intervention, these disruptions will result in production losses particularly in sustainable agriculture, even though the scale and extent of the losses is not yet known. Third, the extent of some of the losses will justify intervention to facilitate adaptations of the invertebrates, even though the methods with which to intervene and policies to facilitate this intervention are not yet in place. © 2013 CAB International.

This study focuses on three main groups of organisms: soil invertebrates, biological control agents (BCAs) and pollinators. These groups play key roles in agricultural systems, and have the potential to be used, moved or manipulated for the benefit of agriculture. Soil invertebrates are a key component of agricultural landscapes. They participate in essential soil processes that maintain healthy productive soils in the face of changing environmental conditions. Reducing the diversity of a community of soil invertebrates reduces its beneficial functions and services, with drastic ecological effects such as long-term deterioration of soil fertility and agricultural productive capacity. The introduction of a keystone species may have detrimental or beneficial effects depending on the context. The interaction between soil invertebrates and soil microorganisms is critical: the activities of soil invertebrates regulate microbial activity in soils, and micro-organisms enter into intimate relationships with soil invertebrates to help them degrade highly complex compounds such as cellulose. Different groups of invertebrates provide biological control of crop pests. In many situations, they form the basis of, and tools for, the integrated pest management (IPM) approach. Given that the losses caused by pre- and post-harvest pests can be very substantial, the potential benefits of using invertebrates as BCAs are vast, but as yet only partially tapped. The potential for soil invertebrates to assist in this function is still largely unknown. Pollination services by animals, especially by insects, are among the most widespread and important processes that structure ecological communities in both natural and agricultural landscapes. An estimated 60-90% of the world's flowering plants - including a range of economically important species - depend on insects for pollination. Crop pollination used to be (and often still is) provided by wild pollinators spilling over from natural and s

[EN] Disentangling how communities of soil organisms are deterministically structured by abiotic and biotic factors is of utmost relevance, and few data sets on co-occurrence patterns exist in soil ecology compared to other disciplines. In this study, we assessed species spatial co-occurrence and niche overlap together with the heterogeneity of selected soil properties in a gallery forest (GF) of the Colombian Llanos. We used null-model analysis to test for non-random patterns of species co-occurrence and body size in assemblages of earthworms and whether the pattern observed was the result of environmental heterogeneity or biotic processes structuring the community at small scales by means of co-inertia analysis (CoIA). The results showed that earthworm species co-occurred more frequently than expected by chance at short distances, and CoIA highlighted a significant specific relationship between earthworm species and soil variables. The effect of soil environmental heterogeneity on one litter-feeding species but also the impact of soil-feeding species on soil physical properties was revealed. Correlogram analysis on the first axis extracted in the CoIA showed the scale of the common structure shared by the fauna and soil variable tables. The earthworm community was not deterministically structured by competition and co-occurrence of competing species was facilitated by soil environmental heterogeneity at small scales in the GF. Our results agreed with the coexistence aggregation model which suggests that spatial aggregation of competitors at patchily distributed resources (environment) can facilitate species coexistence.

[EN] In this study, we investigated the spatial distribution of an earthworm community together with the heterogeneity of selected soil properties in a gallery forest (GF) of the Colombian “Llanos”. We performed fine-scale spatial variability by intensively sampling 100 points distributed in the nodes of a regular grid with 5 m inter-sample distance. Non-parametric statistics were used and included SADIE analysis and partial Mantel test, in addition to geostatistics (semi-variograms) and correlogram computation. Our results indicated that the spatial distribution of earthworms was characterized by areas of presence (patches) and absence (gaps), although the general pattern was random at the scale of this study (<5 m), while soil physico-chemical characteristics showed a clumped spatial distribution. Contrary to previous results reported for the nearby savanna, a significant spatial association was found for two competing endogeic species Andiodrilus sp. and Glossodrilus sp. in the GF. Semi-variograms of soil environmental factors were adjusted to model families most commonly used (spherical and linear), and correlograms for earthworms showed significant positive and negative spatial autocorrelation for lag distances <15 m and >30 m, respectively. Partial Mantel test revealed specific significant relationships between soil variables and some species. The earthworm community of the GF displayed a random structure in a spatially clumped soil environment, and our results suggested that spatial distribution observed for some species could be the result of preferential selection of soil environmental factors. In other words, soil heterogeneity contributed to the formation of population patches for some earthworm species. The variability of suitable sites (resource availability patchiness) exerted an influence in the spatial distribution of earthworms at the scale used in this study, and we identified the spatial scale at which both environmental heterogeneity could influe

Earthworm assemblages are usually spatio-temporally structured in mosaics of patches with different species composition. We re-analysed results of past research carried out in Eastern Colombia to explore how interspecific competition accounts for this pattern. In three sown pastures and three native savannas, density data matrices were obtained from spatially explicit samplings at several successive dates, and spatio-temporal patterns of species assemblages were described through partial triadic analyses and geostatistics. This first analysis detected assemblage patchiness in the six plots at spatial scales ranging from 6 to 33 m. Species richness ranged from 5 to 6 species per plot. Null models were further used to analyse niche overlap and morphometric distribution patterns at two different scales, i.e. at the ‘plot level’ and the ‘patch level’. Seasonal and vertical niche overlaps were higher than expected by chance at both scales, indicating high environmental constraints on assemblage membership. Within-patch overlaps were lower than plot-scale overlaps. Biometric niche overlap was random at the plot level and was weakly lower than that expected by chance in patches. Body weight was significantly overdispersed and constant whatever the scale, while body length and diameter showed a similar trend within patches. These results suggest that earthworms form distinct assemblages within patches, mainly driven by deterministic responses to competition: ecologically similar species avoid competition through spatial segregation, whereas a minimal level of ecological segregation is required to allow co-existence in a given patch.