Freshwater ponds and lakes have often been used as model systems to study different aspects of metacommunity dynamics. However, the role of niche‐ and dispersal‐based dynamics on aquatic organisms of alpine lentic water bodies is still largely unknown. Alpine lakes and ponds are considered sentinels of environmental change and hence represent an ideal system model to study the effects of global warming on metacommunities. The rise of temperature and the changes in the patterns of precipitation as a result of anthropogenic climate change will have important outcomes on the ponds' hydrology. These hydrological changes can have important implications for the structure of pond metacommunities.
The Sierra Nevada (SN) mountain range in Spain (maximum altitude 3,482 masl) is the southernmost high mountain system in Europe and represents one of the areas with the highest values of biodiversity and endemism of the Iberian Peninsula. Sierra Nevada hosts a system of ~50 ponds of glacial origin between approximately 2800 and 3100 masl, and many of these have been analysed in numerous limnological studies. These remote ponds harbour relatively simple biological communities because of their environmental homogeneity, but contain highly specific, cold-adapted species assemblages.
Insects from orders Diptera, Coleoptera and Hemiptera are known to inhabit this system of alpine ponds, with diving beetles (Family Dytiscidae) dominating the aquatic macroinvetebrate community in terms of biomass and species richness. Populations of each taxon in the ponds represent metapopulation systems with frequent extinction and colonization processes; with the interaction of taxa metapopulations determining the metacommunity dynamics.
OBJECTIVES
The main goal of this research proposal is to understand the potential effects of climate change on macroinvertebrate metacommunity structuring of Mediterranean alpine ponds. Specifically, we aim to disentangle the spatial distribution of five cohabiting dytiscid beetles, their metapopulation dynamics and coexistence mechanisms, as well as to test whether climate change can cause shifts in metacommunity structure.
Specific aims:
O1. To determine the spatial patterns in the genetic population structure of the focal species. We will study population genetic patterns and how these are explained by distance between habitat patches and mountain landscape characteristics such as elevation, river valley identity and mountain ridges.
O2. To compare multi-stress tolerance of species. We will develop experimental tests in the laboratory to study behavioural and physiological responses to combinations of temperature and desiccation stress.
O3. To determine mechanisms of coexistence of species (habitat filtering, niche differentiation, priority effects) through field co-occurrence patterns and the characterization of their ecological niche. We will characterize different aspects of the ecological niche (habitat specialization and functional niche) of each species and their niche overlap, using behavioural, physiological and biological traits obtained from field and laboratory approaches, as well as through competition experiments.
O4. To estimate shifts in metacommunity structure under climate change. We will infer changes in the structure of alpine pond metacommunities by integrating all the information obtained from all the previous goals. We will use correlative and hybrid species distribution models that incorporate dispersal, physiology and population dynamics in order to estimate range dynamics of individual species and infer changes in the composition, structure and functioning of metacommunities.
Hydroporus marginatus
(Duftschmid, 1805)
Boreonectes ibericus
(Dutton & Angus, 2007)
Hydroporus nevadensis
(Sharp, 1882)
CONTEXT
Agabus nevadensis
(Lindberg, 1939)
Hydroporus sabaudus sierranevadensis
(Shaverdo, 2004)
