Center for International Tropical Agriculture

Harare, Zimbabwe

Center for International Tropical Agriculture

Harare, Zimbabwe
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Hergoualc'h K.,Center for International Forestry Research | Gutierrez-Velez V.H.,Center for International Forestry Research | Gutierrez-Velez V.H.,Temple University | Menton M.,Center for International Forestry Research | And 2 more authors.
Forest Ecology and Management | Year: 2017

Peru has the fourth largest area of peatlands in the Tropics. Its most representative land cover on peat is a Mauritia flexuosa dominated palm swamp (thereafter called dense PS), which has been under human pressure over decades due to the high demand for the M. flexuosa fruit often collected by cutting down the entire palm. Degradation of these carbon dense forests can substantially affect emissions of greenhouse gases and contribute to climate change. The first objective of this research was to assess the impact of dense PS degradation on forest structure and biomass carbon stocks. The second one was to explore the potential of mapping the distribution of dense PS with different degradation levels using remote sensing data and methods. Biomass stocks were measured in 0.25 ha plots established in areas of dense PS with low (n = 2 plots), medium (n = 2) and high degradation (n = 4). We combined field and remote sensing data from the satellites Landsat TM and ALOS/PALSAR to discriminate between areas typifying dense PS with low, medium and high degradation and terra firme, restinga and mixed PS (not M. flexuosa dominated) forests. For this we used a Random Forest machine learning classification algorithm. Results suggest a shift in forest composition from palm to woody tree dominated forest following degradation. We also found that human intervention in dense PS translates into significant reductions in tree carbon stocks with initial (above and below-ground) biomass stocks (135.4 ± 4.8 Mg C ha−1) decreased by 11 and 17% following medium and high degradation. The remote sensing analysis indicates a high separability between dense PS with low degradation from all other categories. Dense PS with medium and high degradation were highly separable from most categories except for restinga forests and mixed PS. Results also showed that data from both active and passive remote sensing sensors are important for the mapping of dense PS degradation. Overall land cover classification accuracy was high (91%). Results from this pilot analysis are encouraging to further explore the use of remote sensing data and methods for monitoring dense PS degradation at broader scales in the Peruvian Amazon. Providing precise estimates on the spatial extent of dense PS degradation and on biomass and peat derived emissions is required for assessing national emissions from forest degradation in Peru and is essential for supporting initiatives aiming at reducing degradation activities. © 2017 The Authors


Heinritz S.N.,University of Hohenheim | Hoedtke S.,University of Rostock | Martens S.D.,Center for International Tropical Agriculture | Peters M.,Center for International Tropical Agriculture | Zeyner A.,University of Rostock
Livestock Research for Rural Development | Year: 2012

Herbage of Cratylia argentea, Desmodium velutinum, Fleminigia macrophylla, Leucaena diversifolia, Canavalia brasiliensis, Centrosema brasilianum, Clitoria ternatea, Lablab purpureus, Stylosanthes guianensis and Vigna unguiculata from the CIAT (International Center for Tropical Agriculture) gene bank were assessed for their nutritional value and in-vitro digestibility for pigs in order to predict their potential as alternative protein supplement in a tropical smallholder context. Crude protein (CP) contents ranged from 137 to 257 g kg -1 dry matter (DM) (mean 191 g kg -1 DM), although a considerable proportion of it, 27% on average, was bound to neutral detergent fiber (NDF). Interesting levels of lysine were found in Cratylia argentea (14 g kg -1 DM) and Leucaena diversifolia (13 g kg -1 DM), whereby the latter was also high in tannic acid concentration (49 g kg -1 DM) thus limiting the amino acid digestibility. Vigna unguiculata presented highest in-vitro enzymatic degradability (521 g kg -1 DM), which even increased in a 40:60 mixture with maize. Lowest degradation was obtained with Flemingia macrophylla (248 g kg -1 DM), while the median of the forages approached 390 g kg -1 DM. It is concluded, that Vigna unguiculata herbage meal has the highest potential to be successfully included in pig diets, while Cratylia argentea meal should equally be assessed in vivo.


Nkala P.,University of Natural Resources and Life Sciences, Vienna | Mango N.,Center for International Tropical Agriculture | Corbeels M.,CIRAD - Agricultural Research for Development | Veldwisch G.J.,Wageningen University | Huising J.,Soil Scientist and Coordinator of the Below Ground
African Journal of Agricultural Research | Year: 2011

Low crop productivity, food insecurity, hunger and malnutrition; inadequate farming knowledge and skills, implements and inputs are characteristic of smallholder agriculture in Southern Africa. Many researchers argue that conservation agriculture can guarantee higher crop productivity, food security, improved livelihoods and environmental protection, better than the unsustainable traditional systems of slash and burn practices. In this paper, we present the results of a meta-analysis of over 40 academic publications to review conservation agriculture's role in influencing desired livelihood outcomes in Southern Africa. We conclude that the effectiveness of conservation agriculture towards better livelihood outcomes in Southern Africa remains debatable, especially when supportive government policies are lacking. © 2011 Academic Journals.

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