Kilimanjaro, which is Africa's tallest peak and a major ecological resource in Tanzania, supports millions of residents who depend on it for food, timber, and water regulation. However, the region faces mounting pressures from urban sprawl, agricultural intensification, and the transformation of savannah and forest into farmland. Between 1913 and 2022, population density on the lower mountain rose dramatically from 30 to 430 people per square kilometer, closely tracking with the observed loss in plant species richness.
Contrary to earlier assumptions that climate change is the foremost threat to mountain biodiversity, the study demonstrates that climate factors have not had a measurable direct effect on Kilimanjaro's plant diversity at the local scale. Researchers instead stress that conversion of natural landscapes into intensively farmed fields and rapid urban build-out have fragmented habitats, isolated populations, and disrupted gene flow. The shift toward monoculture agriculture and increased resource extraction has diminished native vegetation, leading to the near disappearance of many species in lower-elevation ecosystems.[3][4][1]
The loss of unique plant assemblages affects not only floral biodiversity, but also critically reduces the wider ecosystem services Kilimanjaro provides, including soil fertility, water retention, and carbon storage. Specialists from Germany, Switzerland, Japan, and Finland collaborated to validate these findings across diverse vegetation zones, reinforcing that savannah areas at the base of the mountain are especially vulnerable to overuse and are now nearly encircled by developed land.[4][3]
The authors highlight that traditional, diversified agroforestry systems and the establishment of protected areas show promise for preserving biodiversity in the Kilimanjaro region. Practices such as "Chagga homegardens" - which combine crop species under remnants of forest canopy - offer sustainable models that sustain both biodiversity and local livelihoods. However, the continued expansion of population and loss of natural corridors threaten to transform Kilimanjaro into an "ecological island," isolating species and exacerbating genetic erosion.[3]
"Our research reveals that land-use change driven by rapid population growth - not climate change - was the primary direct driver of biodiversity loss on Mount Kilimanjaro over the past century, with up to 75% of natural species per km lost on the lower slopes. Encouragingly, traditional agroforestry and protected areas emerged as promising strategies for mitigation."
"Investigating a century of ecological change on Kilimanjaro allowed us to disentangle complex human and environmental impacts. This study was the first, to our knowledge, to link human population densities with plant species densities at a 1 km scale in a tropical region - made possible by combining remote sensing with extensive ground-based species data. The process required cleaning and verifying ecological field data across diverse vegetation types, highlighting the critical role of biological collections and the taxonomic expertise of herbaria worldwide."
The study underscores that protecting and restoring natural corridors, implementing sustainable agricultural practices, and addressing the root causes of habitat destruction are urgently needed to prevent further losses. The resilience of Kilimanjaro's ecosystems - and the human populations that depend on them - requires policy and conservation focus on equitable land and resource management.
Research Report:Gain and loss: Human and environmental wellbeing - drivers of Kilimanjaro's decreasing biodiversity
Related Links
PLOS
Forestry News - Global and Local News, Science and Application
| Subscribe Free To Our Daily Newsletters |
| Subscribe Free To Our Daily Newsletters |
