Ecology
Research topics
Miombo forests in Angola, Zambia and Namibia
Clearing for charcoal production, hunting, wildfires and the often illegal logging of valuable hardwood all degrade the Miombo woodlands, which still represent one of the last pristine forest ecosystems on earth. We investigate the ecosystem functions and services of the Miombo in Angola and Zambia, together with the dynamics of its degradation.
Francisco Maiato Amândio Gomes Manfred Finckh Rasmus Revermann
Nature conservation research in the Richtersveld National Park in South Africa
The Richtersveld National Park in the North Cape Province of South Africa allows the continuation of traditional nomadic land use with sheep and goats. We use experiments to investigate the consequences of different grazing methods on vegetation.
Pollinator networks in Morocco and Tunisia
We investigate the diversity and abundance of pollinators and their interactions with existing wild plants on our long-term observation plots in Morocco, as well as on plots at the edge of the Sahara in central Tunisia. From the observations gained, pollinator networks can be created which allow an estimation of the specialization of different pollinators on existing plant species. Additionally the complexity of these networks provides information about the system stability of the pollination processes within the observed locality. Furthermore we are studying the influence of land use, climatic conditions and altitude gradients on the species composition and the behaviour of local pollinator communities.
Hayfe Chamkhi Kristin Krewenka Manfred Finckh
Purgatories – Fire experiments in Angolan suffrutex-grasslands
Recurrent fires in the dry season are a common feature of Africa’s Miombo region and shape the boundaries and extent of the forest-grassland mosaic. The current vegetation is thought to be well adapted to fire disturbances, as many C4-grasses, geoxylic suffrutices, and trees either tolerate low intensity fires or readily resprout after burning.
Although today fires are a frequent disturbance factor in these landscapes, the vast majority of fires are manmade and thus fire frequency, seasonal timing and fire return period are controlled by people. The timing of fires in the dry season, however, has a great impact on fire intensity since the biomass/fuel becomes drier and the ambient temperature hotter with progressing dry season. Until now it is poorly understood how the vegetation of Angola’s highly diverse natural suffrutex-grasslands reacts to different timing and return intervals of fire. Particularly the effects on vegetation structure, i.e. growth height and dominant life forms, and on species composition (via competition between early and late succession species) are assumed to be great.
To quantify the effect of different fire treatments on vegetation structure and species composition we established systematic fire experiments (Purgatories) at sites typical for suffrutex-grasslands in central Angola, related to the Biodiversity Observatories (Bicuar National Park, S75, and Cusseque, S74). Research is done in close cooperation with the team of Dr. Fernanda Lages from ISCED da Huíla in Lubango.
Each Purgatory comprises a hectare of grassland divided into a 15 m x 15 m grid with a 5 m fire break along the outer edges. We apply three different treatments following a random design: 12 plots are burned early in the dry season, 12 late in the dry season and 12 are not burned at all. A complete vegetation survey follows in the subsequent wet season, including measurements of selected traits of perennial grasses, suffrutices and tree species.
Paulina Zigelski Manfred Finckh
Aerial image from the purgatory in Bicuar National Park in August 2017 (Photo:Fernanda Lages)
Controlled burning of early plots in June 2017 (Photo:Paulina Zigelski)
Rangeland ecology in Morocco
The southern edge of the High Atlas represents the transition from the Mediterranean zone to the Sahara. Since 2001, we have been investigating the effects of intensive grazing and firewood extraction on vegetation on 35 permanent observation plots along a transect from the high mountains into the desert. Changes in species composition and the population structure of persistent plant species are just as much a focus as forms of mobile pasture farming.
Sustainable resource management in the Okavango catchment
The natural resources of the Okavango catchment area are fresh water, flowing from the Central Angolan Plateau into the arid regions of Namibia and Botswana, and the nowadays still pristine Miombo woodlands. Both resources, however, are increasingly being changed due to overexploitation and anthropogenic disturbances. With unchanged continuation of current land use practices, critical tipping points will irreversibly be crossed in the next one or two decades which will inevitably lead to sustenance problems for people in the region.
Termites and ants as ecosystem engineers in Africa
Termites not only create the famous fairy circles of the Namib, but also create whole ecosystems in the savannah areas of Africa to their advantage, whereby often enormous quantities of soil material are transported. We investigate in detail the interactions between termites, ants and plants in Angola, Zambia, Namibia, Botswana and South Africa.
Norbert Jürgens Felicitas Gunter
Macrotermes falciger termitarium at Kafue in Zambia
Vegetation Ecology of the Namib
Along its 2000 km from Central Angola to South Africa, the Namib is distinguished by an extreme wealth of different ecosystems. We map the entire area with its organisms and examine many of the ecosystems in detail.
Net dunes near Dieprivier (Namibia)
Vegetation eccology of the succulent Karoo
Using vegetation-ecological methods we investigate the various drivers of the vegetation patterns in the species-rich succulent Karoo of South Africa. The focus of the investigations is on the vegetation of the quartz fields which are of high conservation value and the vegetation of the rangelands.
Vegetation of the quartz fields in the Succulent Karoo.
Wadi vegetation in Egypt
In cooperation with scientists from the Desert Research Center in Cairo, we investigate the ecology and diversity of plant communities in desert and mountain wadis of the Gebel Elba Mountains in south-east Egypt. Wadis are dry riverbeds that only lead water after rainfall. We investigate specifically how diversity behaves along the height gradient, as well as vegetation-environment relationships that determine the differences between different societies.