Informations et ressources scientifiques
sur le développement des zones arides et semi-arides

Titre : Seasonal population dynamics of diurnal butterflies in East Africa’s gallery-forest and dry Savannah biome

Auteur : Stieringer, Daniel

Université de soutenance : Universität Salzburg

Grade : Master of Science, MSc 2021

Résumé
Human activities have altered the face of the earth to a decisive extent. Most Scientists interpret the ongoing biodiversity crisis as human driven and articulate the possibility of stumbling into an 6th mass extinction event. In contrast to temperate zone habitats the pressure on tropical ecosystems is thought to become even more drastically since unsustainable deforestation and degradation of ecosystems is rapidly increasing. Research addressing the specific ecology of biota is highly relevant for enabling a holistic picture of local diversity and for assessing the impact of mankind on local communities and biodiversity. Applied nature conservation relies on low- cost techniques ; the indicator species approach is seen as potentially highly efficient and feasible. Many butterfly species are recognised as indicator species for assessing the ecological status of a particular habitat. To account for shortcomings in biodiversity assessment and evaluation of temporal succession in East Africa’s dry savannah field studies, incorporating inter- annual variation in species assemblages, were carried out. Conducting field studies and following a non- metric multidimensional scaling approach we detect pronounced seasonal fluctuations and temporal succession considering butterfly community assemblages. Fluctuations in natural habitats exceed fluctuation in anthropogenically shaped environments, reflecting dampening of seasonal effects by additional nectar provisioning of crop plants. We assume that this process can dampen short term effects of biodiversity loss, but could, in the long run, further deteriorate ecosystem stability. We propose a combination of Indicator species characteristic for disturbed and partially degraded dry Savannah, namely widespread and insensitive to human disturbance Hypolimnas misipus, Papilio demodocus and Acrea eponina and indicator species characteristic for intact East African Gallery- forest and dry Savannah biome (Hamanumida daedalus, Salamis anacardii and Charaxes zoolina).

Mots clés :

Présentation

Version intégrale (2 Mb)