MSc Student
Advisor: Konrad Fiedler

Department of Botany and Biodiversity Research
University of Vienna

Abstract

Although tropical rainforests are the most diverse terrestrial ecosystems worldwide, ongoing forest degradation and land conversion endanger these precious ecosystems. Aside from designating protected areas, reforestations with native tree species and sustainable forest management by local people are a promising strategy to counteract the losses. The Biological Corridor La Gamba (COBIGA) in SW Costa Rica preserves old-growth forests and reforests former agricultural land to establish patches of secondary forest, which form a connecting corridor between the larger, pristine forests of two national parks. The reforestation areas also function as a unique study system, offering a chronosequence of different successional stages. Nocturnal moths, and particularly the diverse subfamily of Arctiinae (Erebidae), are regularly used as focal taxon for tropical biodiversity research, as they are tightly entangled with their environment and occupy species-specific ecological niches. Thus, they reflect the condition and complexity of the ecosystem itself. While the community composition of the regional old-growth forests is well-known from previous studies, this study investigates if and how fast the moth communities of the reforested areas recover. It is hypothesized that community composition will approximate the original state over time, with certain taxa taking more time than others (thereby potentially acting as indicator taxa). To further investigate this hypothesis, Arctiinae communities were investigated simultaneously at two old-growth forests and three reforestations of varying age. At each site, two sampling locations were identified and sampled from mid-March to the beginning of June 2022 with automatic funnel traps and LED lamps as light sources. In total, 50 samplings (= trap nights) were carried out. Additionally, parameters on vegetation structure were recorded at each sampling site. The collected specimens were tentatively sorted and counted at the La Gamba field station, while species identification started upon return to the University of Vienna, where sufficient space, access to relevant literature and advice by taxonomic experts is available. Selected individuals were also barcoded for identification. After species identification is complete, analysis of the community composition will include the parameters on vegetation structure as explanatory variables, together with the time passed since reforestation, the size of the reforested area as well as the distance from old-growth forests. The findings of the thesis will not only provide valuable information about the current state of the reforested areas of the COBIGA but also shed light on the sensitivity of tropical moth species to human influence. Finally, I will be able to reveal which species profit from reforestations, and which species depend on the protection of pristine old-growth forests.