Spatial Variation of Above Ground Biomass and Diversity of Trees in Nyungwe Montane Rain Forest in Rwanda

• Tropical rainforest plays an important role in the global terrestrial carbon cycle. This zone is undergoing rapid deforestation and degradation due to clearance for croplands, cattle pasture, logging and shifting cultivation. Few tropical forest sites have been the object of forest C cycle studies in detail. The lack of field data on the status of carbon stock and fluxes in central Africa is evident, which together with the high diversity of tree species contributes to the uncertainties in understanding the source/sink relationship of tropical African forests. A study has therefore been initiated to address questions on biodiversity (plant species), carbon fluxes and stocks and scaling of results to whole forests. The study aims at answering the following research questions: Is high diversity connected to high carbon stocks? Is variation in vegetation structure linked to the variation in carbon storage? Are nutrients, climate, disturbances (fire, logging) or topography important determinant factors for carbon storage and biodiversity? The study will be conducted in Nyungwe montane rain forest gazetted as a National Park to protect its extensive floral and faunal diversity covering an area of 970km2. Nyungwe is located in Southwest Rwanda (2o17´-2o50´S, 29o07´-29o26A´E). The forest is ranging between 1600-2950 m.a.s.l. and is one of the most biologically important rainforest in Albertine Rift region in terms of Biodiversity. Nyungwe consists of a mixture of primary and secondary forest. It supports a richness of plant and animal life. More than 260 species of trees and shrubs have been found at Nyungwe, including species endemic to the Albertine Rift. Nyungwe is also one of the most important sites for bird. 260 bird species have been found, some are endemic to the Albertine Rift. Thirteen species of primates populate the forest, including chimpanzees. The forest has a climate with a mean annual temperature of 15.5oC and rainfall averages 1744 mm/yr, with July and August being the only months when rainfall drops. Many forms of human disturbance occur in the forest, including fires, tree cutting, gold mining, honey collection, trapping, and poaching. In this study an east-westerly transect of experimental plots is to be set up where different types of forest occur on approximately the same altitude 2400-2500 m.a.s.l. primary forests stands, secondary forests stands and plantations in the buffer zones. We are sampling within the two plant communities with the highest relative density of Syzygium guineense (18.2 %) representing primary forest and Macaranga kilimandscharica (17.5 %) representing secondary forest and in the two most frequently occurring genus in the buffer zone: Eucalyptus and Pinus. We will describe forest C dynamics in different live biomass components (aboveground and belowground live biomass) and soil organic matter divided into two components: litter and humus. Finally we will investigate fluxes between Carbon pools on live over-story and under-story of trees, shrubs, herbs, and its fine roots. An outline of the study, together with results from an initial measurement campaign on spatial diversity of trees species and above ground biomass, is currently being compiled and will be reported.

Ämnesord

NATURVETENSKAP  -- Geovetenskap och miljövetenskap -- Miljövetenskap (hsv//swe)

NATURAL SCIENCES  -- Earth and Related Environmental Sciences -- Environmental Sciences (hsv//eng)

NATURVETENSKAP  -- Biologi (hsv//swe)

NATURAL SCIENCES  -- Biological Sciences (hsv//eng)

NATURVETENSKAP  -- Biologi -- Ekologi (hsv//swe)

NATURAL SCIENCES  -- Biological Sciences -- Ecology (hsv//eng)

Nyckelord

Tropical montane forests

biodiversity

carbon dynamics

nutrient dynamics

biomass

Publikations- och innehållstyp

vet (ämneskategori)

kon (ämneskategori)