Jesús Pozo | University of the Basque Country, Euskal Herriko Unibertsitatea (original) (raw)

Papers by Jesús Pozo

Advances in Ecological Research, 2016

Methods to Study Litter Decomposition

... Thus local benthic CPOM is related to the riparian vegetation, underlining the strong influen... more ... Thus local benthic CPOM is related to the riparian vegetation, underlining the strong influence of the terrestrial environment on the energy basis of low-order forest streams (Wallace et al. 1999). ... (1997); 8 = Smock (1990); 9 = Wallace et al. (1999); 10 = Webster et al. ...

With 3 figures and 4 tables Abstract: The life history and temporal dynamics in density, biomass,... more With 3 figures and 4 tables Abstract: The life history and temporal dynamics in density, biomass, growth rate and secondary production of Habrophlebia lauta and Habroleptoides confusa were compared in 3 sites along the Agüera stream in northern Spain. Both species had univoltine winter life histories. Hb. lauta showed greater abundance and production at downstream sites, while Hd. confusa did at the headwater site. The life history and temporal dynamics in population parameters differed between both species. As a result, temporal overlaps of abundance and, especially, production of these two mayflies were very low, which suggests that irrespective of their abundance, interspecific competition between Hb. lauta and Hd. confusa was unimportant along this stream system.

The Science of the total environment, Jan 14, 2017

Climate change and anthropogenic disturbances are expected to lead to more intense and frequent d... more Climate change and anthropogenic disturbances are expected to lead to more intense and frequent droughts, with potentially severe effects on structure and function of perennial temperate streams. However, more information is required on whether streams flowing through basins already affected by exotic plantations will respond to droughts in the same way as streams under native forests. The recolonisation dynamics of benthic macroinvertebrate communities and leaf litter decomposition rates were examined in nine streams of oceanic-temperate climate that differed in catchment vegetation (three streams draining native deciduous forest, three in pine plantations and three in eucalypt plantations) after a marked drought. In each stream, five benthic samples were collected three times (ca. 1.5months between sampling dates) after flow recovery, and the taxonomic and functional trait compositions of the macroinvertebrate communities were analysed. The decomposition rate of Alnus glutinosa wa...

Knowledge and Management of Aquatic Ecosystems, 2016

Canadian Journal of Fisheries and Aquatic Sciences, 2016

Human activities enhance the atmospheric CO2 concentration and modify climatic patterns, which co... more Human activities enhance the atmospheric CO2 concentration and modify climatic patterns, which could change the growth and quality of plant materials, as well as their subsequent decomposition, thus altering stream ecosystem functioning. These effects could be modulated by interactions between plant species differing in biological traits and competitive capacity. We cultivated the forb Trifolium pratense and the grass Agrostis capillaris under different CO2 concentration (ambient or elevated), water availability (control or drought), and competition (monoculture or mixture). The material thus grown was conditioned in a stream for microbial colonization, and its subsequent decomposition was measured in laboratory microcosms. Elevated CO2 reduced the quality of T. pratense but not that of A. capillaris. Water shortage limited plant quality but did not interact with CO2 concentration. Interspecific competition only affected nitrogen concentration in A. capillaris. Elevated CO2 did not ...

PloS one, 2018

Biodiversity loss in riparian forests has the potential to alter rates of leaf litter decompositi... more Biodiversity loss in riparian forests has the potential to alter rates of leaf litter decomposition in stream ecosystems. However, studies have reported the full range of positive, negative and no effects of plant diversity loss on decomposition, and there is currently no explanation for such inconsistent results. Furthermore, it is uncertain whether plant diversity loss affects other ecological processes related to decomposition, such as fine particulate organic matter production or detritivore growth, which precludes a thorough understanding of how detrital stream food webs are impacted by plant diversity loss. We used a microcosm experiment to examine the effects of plant diversity loss on litter decomposition, fine particulate organic matter production, and growth of a dominant leaf-shredding detritivore, using litter mixtures varying in species composition. We hypothesized that plant diversity loss would decrease the rates of all studied processes, but such effects would depend...

Revista de Estudios del Campo de Montiel, 2021

En un pequeño territorio de las comarcas del Campo de Montiel y de la Sierra de Alcaraz (sur de C... more En un pequeño territorio de las comarcas del Campo de Montiel y de la Sierra de Alcaraz (sur de Castilla-La Mancha, España) se inician las redes de drenaje de 4 de las principales cuencas hidrográficas de la Península Ibérica: Guadalquivir, Guadiana, Júcar y Segura. Este trabajo pretende examinar la variabilidad físico-química de los ríos de cabecera de estas cuencas. Visores geográficos, medidas de campo y análisis de aguas en laboratorio han proporcionado los datos que indican que orografía, litología y clima condicionan el régimen hidrológico de estos ríos, muchos de ellos, intermitentes o efímeros. Escasez de agua y contaminación por nitratos derivados de la agricultura son problemas que podrían agravarse con el cambio climático, especialmente en la cabecera del Guadiana.

Forest Ecology and Management, 2016

Scientific Reports, 2020

Plant litter decomposition is a key ecosystem process that can be altered by global changes such ... more Plant litter decomposition is a key ecosystem process that can be altered by global changes such as biodiversity loss. These effects can be particularly important in detritus-based ecosystems, such as headwater streams, which are mainly fuelled by allochthonous plant litter inputs. However, experiments examining effects of plant diversity on litter decomposition in streams have not reached consensus about which measures of biodiversity are more relevant. We explored the influence of two of these measures, plant species richness (SR; monocultures vs. 3-species mixtures) and phylogenetic distance (PD; species belonging to the same family vs. different families), on leaf litter decomposition and associated processes and variables (nutrient dynamics, fungal biomass and detritivore growth), in a stream microcosm experiment using litter from 9 tree species belonging to 3 families. We found a negative effect of SR on decomposition (which contradicted the results of previous experiments) bu...

Ecosystems, 2020

Plant biodiversity loss in riparian forests is known to alter key stream ecosystem processes such... more Plant biodiversity loss in riparian forests is known to alter key stream ecosystem processes such as leaf litter decomposition. One potential mechanism mediating this biodiversity–decomposition relationship is the increased variability of plant functional traits at higher levels of biodiversity, providing more varied resources for decomposers and thus improving their function. We explored this in a field experiment exposing litter from different assemblages with low or high trait variability (measured through phylogenetic distance, PD) to microbial decomposers and invertebrate detritivores within litterbags in a low-order stream. Litter assemblages generally lost less mass but more phosphorus (P) than expected from monocultures, and nitrogen (N) tended to increase in the absence of detritivores and decrease in their presence, with little effect of PD. In contrast, there were strong influences of mean values and variability of specific traits (mostly N, P and condensed tannins) on decomposition and on net diversity effects. The negative diversity effect on litter mass loss was mainly driven by negative complementarity (that is, physical or chemical interference among species or traits), although there was positive selection (that is, particular species or traits with large effects on decomposition) in high-PD assemblages with detritivores. High-PD assemblages tended to have more invertebrates and attracted more typical litter-consuming detritivores. Our study suggests that decomposition of litter assemblages is mainly driven by concentration and variability of several key litter traits, rather than overall trait heterogeneity (measured through PD). However, differences in invertebrates colonizing high-PD and low-PD assemblages pointed to potential long-term effects of PD on decomposition.

The Science of the total environment, 2017

Input of allochthonous leaf litter is the main carbon source for heterotrophic metabolism in low-... more Input of allochthonous leaf litter is the main carbon source for heterotrophic metabolism in low-order forested streams. A major part of this leaf litter is accumulated at benthic retention structures or buried in the hyporheic zone. As a result of hyporheic sediment characteristics, hyporheic physicochemistry differs from that of the benthic zone selecting the microbial community. The present study aimed at understanding the influence of the hydrological and physiochemical differences between the benthic and hyporheic zone on microbial leaf litter decomposition and on the structure and function of the associated microbial community. Leached leaves of Alnus glutinosa were exposed for 62days in 250-μm mesh bags in the benthic zone and buried in the hyporheic zone at a depth of 2-3cm. Decomposition rates were comparable for both zones. In contrast, respiration, bacterial abundance, ergosterol content, fungal spore production and richness of fungal morphotypes were lower associated wit...

Marine and Freshwater Research, 2014

Although the effect of resource quality on density, biomass, growth rate and secondary production... more Although the effect of resource quality on density, biomass, growth rate and secondary production of consumers has been frequently documented, the direct repercussion of resource quality on reproduction has been less investigated. Here we tested the hypothesis that resource quality can limit body-condition recovery of reproducing individuals. For this, we reared ovigerous females of the freshwater amphipod Echinogammarus berilloni in the laboratory and fed them with leaves differing in quality (native Alnus, Quercus, or the exotic Eucalyptus) conditioned in three streams differing in the concentration of dissolved nutrients. Both consumption and growth rate, as well as the length-corrected mass and protein content of females after the release of the eggs, were negatively related to the C : N and C : P ratios of the resource. Survival was significantly lower with the exotic eucalypt leaf litter compared to native alder and oak, a result likely explained by the toxicity of the leaves....