Humans are altering the composition of biological communities through a variety of activities that increase rates of species invasions and species extinctions, at all scales, from local to global. These changes in components of the Earths biodiversity have a strong potential to alter ecosystem. Ecological experiments, observations, and theoretical developments show that ecosystem properties depend greatly on biodiversity in terms of the functional characteristics of organisms present in the ecosystem and the distribution and abundance of those organisms over space and time. Species effects...

Los hongos, como organismos vivos que son, no pueden considerarse aislados ni independientes del medio ambiente en que se desarrollan, ya que se establecen relaciones con los demas seres vivos y el biotopo al que pertenecen. Los hongos son elementos de fundamental importancia en la ecologia de nuestro planeta. Un bosque, un matorral, una pradera, estan influidos fundamentalmente por los hongos que poseen. Desde un punto de vista ecologico se puede decir que son imprescindibles para el mantenimiento del equilibrio de todo tipo de ecosistemas. Contribuyen de forma muy directa a la degradacion...

Nuestro objetivo es describir aquellas especies de setas mas representativas de nuestro entorno provincial, bien por su abundancia, bien por su desarrollo en aquellos biotopos mas asequibles en dias de excursion, por su tamano o sus llamativos colores, y sobre todo seguir catalogando nuestro gran acerbo micologico provincial. En efecto, muchas de las especies conocidas son raras y dificiles de encontrar para el observador casual. Ademas muchas especies solo pueden diferenciarse con un examen meticuloso y detallado de sus diminutas estructuras utilizando un potente microscopio compuesto. Por...

Los mixomicetos son un grupo de organismos con aproximadamente 700 especies descritas hasta la fecha, siendo su determinacion bastante compleja, incluso hay autores que durante mucho tiempo no los han incluido como hongos verdaderos y los han relacionado con las plantas, animales y otros hongos. Se caracterizan porque comparten, en terminos generales, un ciclo de vida compuesto por una fase ameboidal, una plasmodial y una esporangial. Estos organismos se distribuyen practicamente desde los polos hasta los tropicos y el reciente hallazgo de un plasmodio fosilizado en ambar indica que su...

Forest soil respiration is the sum of heterotrophic (microbes, soil fauna) and autotrophic (root) respiration. The contribution of each group needs to be understood to evaluate implications of environmental change on soil carbon cycling and sequestration. Soil respiration is a key ecosystem process that releases carbon from the soil in the form of CO2. This CO2 is acquired from the atmosphere and converted into organic compounds in the process of photosynthesis. Plants use these organic compounds to build structural components or respire them to release energy. When plant respiration occurs...

The aboveground biomass, litterfall and its accumulation, litter weight loss due to decomposition, N return and seasonal leaf N dynamics and nutrient pools in relation to soil properties may be performed in different forest ecosystems in order to better understand the recycling of elements associated with the turnover of organic matter. The leaves were found to accumulate a qualitatively important fraction of mobile nutrients as compared with their low percentage in total above-ground biomass (3%). Nutrient management seems to be related to the availability for the trees of elements such as...

Sweet chestnut (Castanea sativa Mill) stands are very common around the western Mediterranean Basin. Over many centuries, chestnut fruits had an important role as food for humans and as feed for domestic animals, while wood chestnut was used for local purposes such as wine barrels, vineyard pegs, tool handles and carpentry. Until the end of the last century, chestnut stand management has been more or less abandoned owing to rural exodus and diseases. Nevertheless, chestnut stands, groves, coppices, cover large areas in the Mediterranean Basin and particularly in Portugal, Spain, France, Italy...

Decomposition of organic matter derived from plants is an important ecosystem process in many environments, both aquatic and terrestrial. This process underlies soil formation and the liberalization of energy to higher trophic levels. Since consumers do not influence the renewal rate of detritus, this donor controlled resource often serves to stabilize food web dynamics. How species loss influences decomposition rate involves different mechanisms than invoked for plant and consumer communities. In particular, loss of tree species in forests translates into loss of leaf litter species in the...