Usable wild plant species in relation to elevation and land use at Mount Kilimanjaro, Tanzania

Abstract

We used the broad elevational gradient of Kilimanjaro ranging from warm tropical lowland to cold Afroalpine temperature regimes and the occurrence of natural, nearly untouched as well as of anthropogenic and heavily disturbed habitats to study how elevation and disturbance by humans affect the proportion of useful plant species in different habitat types. Of the 962 vascular plant species recorded in our 60 study plots, 563 species turned out to be listed as useful in the literature. We classified these species into six usage categories. With linear models we tested for relationships between the proportion of useful species per plot and elevation for natural habitats, and with analysis of variance we compared the proportion of useful species between plots in disturbed and natural habitats at similar elevation. The proportion of useful species for all usage categories increased from 860 to 2500 m asl and decreased with higher elevation. We also found an overall positive correlation between the number of useful plants and the species richness of our plots. Human-influenced habitats had higher proportions of useful species for all usage categories, except for construction and fuel wood usage which were higher in natural savanna and lower montane forest than in used habitats at these elevations. Given the high proportions of useful species, we conclude that preserving the biodiversity of Kilimanjaro ecosystems is indispensable for maintaining the diversity of useful plants species for the local people who rely on it for food, sustainable access to medicinal, fuel, construction and forage material.

Ecosystem Services and Importance of Common Tree Species in Coffee-Agroforestry Systems: Local Knowledge of Small-Scale Farmers at Mt. Kilimanjaro, Tanzania

“…Rauvolfia caffra ranked as an important shade tree species which is in line with other findings from Mt. Kilimanjaro [22,26]. Fernandes, et al [19] report the potential of R. caffra to suppress various coffee pests.…”

“…Fernandes, et al [19] report the potential of R. caffra to suppress various coffee pests. Its contribution to the production of traditional banana beer underlines its importance in traditional Chagga homegardens [19,22,40]. Croton macrostachyus provides good litter, preserves soil moisture, facilitating high coffee yield and high bean weight [43].…”

“…Although several studies have investigated how the Chagga people living on Mt. Kilimanjaro in Tanzania use their natural environment [19][20][21][22], research has so far not identified which tree species are considered superior in providing relevant ESs for the local coffee farmers. Our aim is to assess indigenous knowledge of local farmers on Mt.…”

Broken bridges: The isolation of Kilimanjaro's ecosystem

“…Since savanna grasslands and woodlands are one of the most important habitat types in terms of plant species numbers, and because the highest diversity is found below 1,000 m (Hemp, ; Peters et al., ), the loss of natural savanna habitats represents a major threat to Kilimanjaro's biodiversity. This affects also traditional medicinal plants, most numerous in the lowlands of Kilimanjaro (Mollel, Fischer, & Hemp, ). In addition, global warming is affecting ecosystem services in particular in savanna habitats with lowest plant–pollinator network robustness at Mt.…”

The climatic challenge: Which plants will people use in the next century?

“…The efficient exploitation of many underutilised useful plants depends to a large degree upon the preservation of associated, and often diverse indigenous knowledge, for example the complex cultivation and processing practices for enset in Ethiopia . It is important to recognise that many communities still cultivate relatively few species, and are reliant on harvested (wild) plants for construction, medicine, tools, food, firewood (and also game animals dependent on plants) (Mollel, Fischer, Hemp, & Fischer, 2017). Indigenous knowledge combined with science has been suggested as one of the most effective approaches to achieving agricultural climate adaptation (Makondo & Thomas, 2018).…”