Aboveground biomass and leaf area index (LAI) mapping for Niassa Reserve, northern Mozambique

Abstract

[1] Estimations of biomass are critical in miombo woodlands because they represent the primary source of goods and services for over 80% of the population in southern Africa. This study was carried out in Niassa Reserve, northern Mozambique. The main objectives were first to estimate woody biomass and Leaf Area Index (LAI) using remotely sensed data [RADARSAT (C-band, l = 5.7-cm)] and Landsat ETM+ derived Normalized Difference Vegetation Index (NDVI) and Simple Ratio (SR) calibrated by field measurements and, second to determine, at both landscape and plot scales, the environmental controls (precipitation, woody cover density, fire and elephants) of biomass and LAI. A land-cover map (72% overall accuracy) was derived , respectively. On the landscape-scale, both biomass and LAI were strongly determined by mean annual precipitation (F = 13.91, p = 0.0002). On the plot spatial scale, woody biomass was significantly determined by fire frequency, and LAI by vegetation type.

Miombo Woodlands Research Towards the Sustainable Use of Ecosystem Services in Southern Africa

“…The impact of fires on biomass and carbon stocks has been addressed in a few countries. [53] in Zimbabwe, [54] and [31] in Zambia, and [46] and [55] in Mozambique have observed that fire protected sites had more woody biomass than frequently burned sites.…”

“…Woody biomass was observed to range from 1.5 Mg ha -1 (3-6 years old coppice) to 144 Mg ha -1 (mature wet Miombo) [9,[41][42][43][44][45]. Dry Miombo ranges between 53-55 Mg ha -1 [45][46][47][48]. It is confirmed that wood and soil compartments are the most important of these stocks [48][49], but grass, litter and root may contribute significantly to carbon sequestration.…”

“…Fires inside the park leveraged elephant's effect by killing young sapling and debarked susceptible trees. [32] and [46] analised the combined effect of fires and elephants in NNR, northern Mozambique, revealing denser woodlands and higher wood biomass in places with low fire frequency and low animal densities. Recently, [48] studied the dynamics of the biomass in the Miombo woodlands in NNR and observed that woody biomass had a net increase of 3 Mg ha -1 in a 5-year period of study.…”

Biodiversity Studies in Key Species from the African Mopane and Miombo Woodlands

“…Arg.) Pichon [51]. In southwestern Tanzania, [50] reported a tree species diversity score (Shannon-Wiener diversity) of 3.44 versus 2.86 in the Miombo woodlands subjected to low and high rates of resource use, respectively.…”

“…In the Niassa National Reserve (NNR), one of the most pristine and least disturbed areas of Africa's deciduous Miombo woodlands, notable alterations in vegetation structure and composition were reported in areas with high ire (mostly anthropogenic) frequency [51,52].…”