Browsing by Author "Burgess, N. D."

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Deforestation and CO 2 emissions in coastal Tanzania from 1990 to 2007
(Foundation for Environmental Conservation, 2011) Godoy, F. L.; Tabor, K.; Burgess, N. D.; Mbilinyi, B. P.; Kashaigili, J. P.; Steininger, M. K.
Conversion of forest to other land uses is a major contributor to climate change. The coastal forests of Tanzania have increasingly been recognized as being of global biodiversity importance, due to high rates of species endemism. Rates of forest loss are similar to those of other tropical regions, resulting in increasing levels of threat for the biological values within the remaining forest and potentially significant source of CO 2 emissions. This study estimated the remaining cover and carbon stock of Tanzania’s coastal forests and the CO 2 emissions due to forest loss between c. 1990 and c. 2007. Coastal Tanzania contained over 273 700 ha of forest in 2007. Deforestation rates in the area have slowed from 1.0 % yr −1 , or > 3735 ha yr −1 during the 1990s, to 0.4 % yr −1 , or > 1233 ha yr −1 during 2000–2007. Despite lower deforestation rates in 2000–2007, the percentage forest lost from within reserved areas has remained steady at 0.2 % yr −1 for both time periods. CO 2 emissions from deforestation slowed from at least 0.63 Mt CO 2 yr −1 in 1990–2000 to at least 0.20 Mt CO 2 yr −1 in 2000–2007. Regional forest clearance in Tanzania is highly dynamic; while rates have slowed since 2000, forest habitat conversion has continued and there is no guarantee that future rates will remain low. A rigorous policy on reducing emissions from deforestation and degradation (REDD) should be implemented to avoid future increases in deforestation rates.
Forest and woodland cover and change in coastal Tanzania and Kenya, 1990 to 2000
(Nature Kenya/East African Natural History Society, 2010) Tabor, K.; Burgess, N. D.; Mbilinyi, B. P.; Kashaigili, J. J.; Steininger, M. K.
Forest and woodland cover and change were calculated for the Zanzibar-Inhambane biogeographical region of Tanzania and Kenya from ~1990 to ~2000. A cover and change map was derived from high-resolution satellite imagery from Landsat and supplemental data from aerial overflights, field surveys, and local knowledge. Analyses showed that around 6820 km2 of coastal forest habitat remained in ~2000 (2260 km2 in Kenya and 4560 km2 in Tanzania). In terms of change, a total of 424 km2 (6%) of forest was cleared between ~1990 and ~2000; 53 km2 in Kenya and 371 km2 in Tanzania. Rates of forest loss were 8 times higher in unprotected areas than in protected sites such as Forest Reserves and National Parks. Key Biodiversity Areas had forest loss rates 2.5 times faster than protected areas while Alliance for Zero Extinction sites had the slowest rates of forest loss for the region. These baseline forest cover and change estimates along with future updates can contribute to national and sub-national carbon emission baselines and assessments of species threat within the global Red List.
Land cover change and carbon emissions over 100 years in an African biodiversity hotspot
(Wiley Researcher Academy., 2016) Willcock, S.; Phillips, O . l.; Platts, P. J.; Swetnam, R. D.; Balmford, A.; Burgess, N. D.; Ahrends, A.; Bayliss, J.; Doggart, N.; Doody, K.; Fanning, E.; Green, J. M. H.; Hall, J.; Howell, K. l.; Lovett, J. C.; Marchant, R.; Marshall, A. R.; Mbilinyi, B.; Munishi, P. K. T.; Owen, N.; Topp-Jorgensen, E. J.; Lewis, S. l.
Agricultural expansion has resulted in both land use and land cover change (LULCC) across the tropics. However, the spatial and temporal patterns of such change and their resulting impacts are poorly understood, particularly for the presatellite era. Here, we quantify the LULCC history across the 33.9 million ha watershed of Tanzania’s Eastern Arc Mountains, using geo-referenced and digitized historical land cover maps (dated 1908, 1923, 1949 and 2000). Our time series from this biodiversity hotspot shows that forest and savanna area both declined, by 74% (2.8 million ha) and 10% (2.9 million ha), respectively, between 1908 and 2000. This vegetation was replaced by a fivefold increase in cropland, from 1.2 million ha to 6.7 million ha. This LULCC implies a committed release of 0.9 Pg C (95% CI: 0.4– 1.5) across the watershed for the same period, equivalent to 0.3 Mg C ha 1 yr 1. This is at least threefold higher than previous estimates from global models for the same study area. We then used the LULCC data from before and after protected area creation, as well as from areas where no protection was established, to analyse the effectiveness of legal protection on land cover change despite the underlying spatial variation in protected areas. We found that, between 1949 and 2000, forest expanded within legally protected areas, resulting in carbon uptake of 4.8 (3.8–5.7) Mg C ha 1, compared to a committed loss of 11.9 (7.2–16.6) Mg C ha 1 within areas lacking such protection. Furthermore, for nine protected areas where LULCC data are available prior to and following establishment, we show that protection reduces deforestation rates by 150% relative to unprotected portions of the watershed. Our results highlight that considerable LULCC occurred prior to the satellite era, thus other data sources are required to better understand long-term land cover trends in the tropics.
Quantifying and understanding carbon storage and sequestration within the Eastern Arc mountains of Tanzania, a tropical biodiversity hotspot
(Carbon Balance and Management., 2014) Willcock, S.; Phillips, O. L.; Platts, P. J.; Balmford, A.; Burgess, N. D.; Lovett, J .C.; Ahrends, A.; Bayliss, J.; Doggart, N.; Doody, K.; Fanning, E.; Green, J. M. H.; Hall, J.; Howell, K. L.; Marchant, R.; Marshall, A. R.; Mbilinyi, B.; Munishi, P. K .T.; Owen, N.; Swetnam, R. D.; Jorgensen, E. J. T.; Lewis, S. L.
Background: The carbon stored in vegetation varies across tropical landscapes due to a complex mix of climatic and edaphic variables, as well as direct human interventions such as deforestation and forest degradation. Mapping and monitoring this variation is essential if policy developments such as REDD+ (Reducing Emissions from Deforestation and Forest Degradation) are to be known to have succeeded or failed. Results: We produce a map of carbon storage across the watershed of the Tanzanian Eastern Arc Mountains (33.9 million ha) using 1,611 forest inventory plots, and correlations with associated climate, soil and disturbance data. As expected, tropical forest stores more carbon per hectare (182 Mg C ha-1) than woody savanna (51 Mg C ha-1). However, woody savanna is the largest aggregate carbon store, with 0.49 Pg C over 9.6 million ha. We estimate the whole landscape stores 1.3 Pg C, significantly higher than most previous estimates for the region. The 95% Confidence Interval for this method (0.9 to 3.2 Pg C) is larger than simpler look-up table methods (1.5 to 1.6 Pg C), suggesting simpler methods may underestimate uncertainty. Using a small number of inventory plots with two censuses (n = 43) to assess changes in carbon storage, and applying the same mapping procedures, we found that carbon storage in the tree-dominated ecosystems has decreased, though not significantly, at a mean rate of 1.47 Mg C ha-1 yr-1 (c. 2% of the stocks of carbon per year). Conclusions: The most influential variables on carbon storage in the region are anthropogenic, particularly historical logging, as noted by the largest coefficient of explanatory variable on the response variable. Of the non-anthropogenic factors, a negative correlation with air temperature and a positive correlation with water availability dominate, having smaller p-values than historical logging but also smaller influence. High carbon storage is typically found far from the commercial capital, in locations with a low monthly temperature range, without a strong dry season, and in areas that have not suffered from historical logging. The results imply that policy interventions could retain carbon stored in vegetation and likely successfully slow or reverse carbon emissions.
Two decades of change in state, pressure and conservation responses in the coastal forest biodiversity hotspot of Tanzania
(Cambridge CB3 0DL, UK, 2016) Burgess, N. D.; Malugu, I.; Sumbi, P.; Kashindye, A.; Kijazi, A.; Tabor, K.; Mbilinyi, B. P.; Kashaigili, J. J.; Wright, T. M.; Gereau, R. E.; Coad, L.; Knights, K.; Carr, J.; Jeahrends, A.; Newh, R. L.
We present an analysis of changes of state, pres- sures and conservation responses over 20 years in the Tanzanian portion of the Coastal Forests of Eastern Africa biodiversity hotspot. Baseline data collected during 1989-1995 are compared with data from a synthesis of recently published papers and reports and new field work carried out across the region during 2010-2014. We show that bio- diversity endemism values are largely unchanged, although two new species (amphibian and mammal) have been named and two extremely rare tree species have been relo- cated. However, forest habitat continues to be lost and de- graded, largely as a result of agricultural expansion, charcoal production to supply cities with cooking fuel, log- ging for timber and cutting of wood for firewood and build- ing poles. Habitat loss is linked to an increase in the number of species threatened over time. The government-managed forest reserve network has expanded slightly but has low ef- fectiveness. Three forest reserves have been upgraded to National Parks and Nature Reserves, which have stricter protection and more effective enforcement. There has also been rapid development of village-owned forest reserves, with more than 140 now existing; although usually small, they are an important addition to the areas being managed for sustainable resource use, and also provide tangible benefits to local people. Human-use pressures remain in- tense in many areas, and combined with emerging pressures from mining, gas and oil exploration, many endemic species remain threatened with extinction.