Dokument

Summary:
Human activities have strongly modified forest ecosystems across Europe. Today, less than 40 % of the total land surface area are covered by forests and only 4 % of those are strictly protected. Forest ecosystems are naturally shaped by disturbances that modulate their structural character-istics at different spatiotemporal scales. In general, intermediate natural disturbances are posi-tively associated with habitat quality and biodiversity, but human interventions strongly modify the spatiotemporal patterns of these dynamics. While habitat generalist species may be able to adapt to these novel dynamics, forest specialist species - often a priority for conservation - mostly respond negatively to human interference. To assess to what extent natural and human disturbances influence an elusive forest specialist species, I focused my research on a population of the Western Capercaillie (Tetrao urogallus) covering two adjacent national parks, Šumava National Park (Czech Republic) and the Bavarian Forest National Park (Germany). In particular, I studied (i) the population size and genetic population structure of the Capercaillie population, (ii) its spatial distri-bution and (iii) its physiological stress response to various disturbance regimes. Within the scope of my studies, I determined a population size of approximately 550 individuals and therefore revealed this population as viable and one of the largest relict populations in the low mountain ranges of temperate Europe. Moreover, autocorrelation analysis revealed no significant spatial genetic structure and unrestricted gene flow across the entire Bohemian Forest. These findings indicate that after a strong decline in population size in the 1970ies the subsequent reenforcement program promoted the longterm conservation of this endangered species. Furthermore, I recorded Capercaillie in more than 60 % of the studied grid cells. The intensity of habitat use (presence/absence and number of Capercaillie records) was negatively associated with increasing anthropogenic recreational activities (tourism) even within suitable habitat types pointing to the avoidance of certain areas with human activities. Forestry activities did not reveal any trend in changes of presence, absence or count data of Capercaillie. These results highlight the relevance of restricting recreation activities even in protected areas by setting aside selected zones to preserve the refuge of this flagship spe-cies. This is clearly supported by my studies showing that the physiological stress response levels of 1.096 individuals decreased with increas-ing habitat quality. Further, increasing tourism intensity was associated with elevated physiological stress response levels at least when controlling for true individuals by the use of genetic fingerprinting technology. Management disturbances in terms of forestry activities – on the other hand – did not indicate any increase in physiological response. These findings suggest that individuals differ considerably in their physiological response to disturbances through touristic recreational ac-tivities. To conclude, I was able to clearly demonstrate that both monitoring of population size and physiological responses - preferably at the individual level - in combination with analyses of habitat quality and possible disturbance factors are adequate tools for delivering valuable baseline data for the development of management strat-egies for the conservation of the Capercaillie, the emblematic forest specialist of both national parks. The overall conservation status indicates a good prerequisite for the future persistence of the population. However, given that only two thirds of the individuals were detected within the boundaries of the national parks, a coherent management strategy particularly regarding the complexity of habitats is essential to guarantee the long-term viability of the population. As the results clearly show that both the spatial distribution patterns and the physiological stress responses respond to touristic recreation activities, a comprehensive cross-border monitoring project in combination with management plans should be established. Such a management plan should provide an intelligent visitor guidance concept with sufficient refuge zones in high quality habitats to preserve this forest specialist species. Moreover, such a monitoring project should also consider changes in forest structures given that the forest still is – after large scale windthrow events and bark beetle calamities – under ongoing successional changes which will likely modulate the habitat use of the Capercaillie. The Capercaillie as forest specialist has been shown to serve as a suitable regional indicator species for guiding the national park authorities in evidence-based and close-to-nature management deci-sions considering both of their aims: wildlife con-servation and sustainable human recreation.

Das Dokument ist im Internet frei zugänglich - Hinweise zu den Nutzungsrechten