Project description

Mountains are a highly heterogeneous, dynamic, yet increasingly vulnerable terrestrial environment undergoing rapid change in the Anthropocene. Mountains are vital for biodiversity and key ecosystem services such as freshwater storage and provision. Mountain regions display large climate gradients within small spatial scales, host a diversity of microclimates and macroclimates, are biodiversity hotspots and priority regions for conservation.

Mountains also intersect important environmental boundaries such as tree lines, snow lines, and freezing lines. They are also systems characterized by intense natural disturbance regimes and perpetual change. However, the dynamic nature of mountain environments is now threatened by pervasive anthropogenic impact.

Mountain ecosystems worldwide face multiple threats arising from global change and its interactions with socio-cultural, economic and political developments. Together, these factors impact on the ability of mountains to support the livelihoods of more than 50% of the human population with essential ecosystem services, such as clean drinking water. Mountain regions have warmed considerably over the last 100 years, at a rate comparable to that of lowland regions and future temperature increases are expected at high altitudes. This makes alpine species particularly suitable for tracing climate-change impacts, most often resulting in a shift of species’ ranges to higher altitudes.

Evidence for such shifts comes mostly from re-visitations of historical sites. Responses to global changes depend on species-specific life-history parameters, so that communities will not respond to climate warming as a whole, but single species will respond in different ways. A further challenge for predicting shifts in alpine community structure is the dual threat of colonization by upward-migrating thermophilic species and conventional alien invasive species.

Alien species spread is promoted by land-use changes (e.g. clearcutting, road construction), grazing and tourism that cause habitat disturbances. This makes mountains excellent model systems for understanding drivers of plant. Thus, understanding the role of life history traits in colonizing success is crucial for predicting changes in species composition under climate change. A new set of species distribution modelling (SDM) tools is being developed that replaces the binary information on species occurrence with fitness-related phenotypic traits.

Retezat National Park was selected as a study site for several reasons:

(i) it is the oldest national park in Romania;

(ii) it was intensively studied, especially in the alpine region where the construction of a research station at 1780 m in the 60’s facilitated access and promoted research that resulted in numerous publications, including several monographs;

(iii) it is a biodiversity hotspot;

(iv) long term climate data is available from a nearby Meteorological station (Tarcu, at 2190 m);

(v) the sediments of the alpine water bodies provided specific paleolimnological proxies that allow reconstruction of past climatic fluctuations and associated ecological changes during the late glacial and the Holocene; while atmospherically deposited persistent organic pollutants, trace elements, and spheroidal carbonaceous particles allowed to infer past pollution history as early as the 16th century;

(vi) Despite its high conservation value, RNP was subjected to grazing and locally overgrazing, fish stocking in alpine lakes, tourism and atmospheric pollution from nearby coal mines and steel factories.

All these available historical datasets provide a unique opportunity for estimating the response and developing models regarding the trajectory of alpine ecosystems and communities in response to global changes.