Effects of Deforestation and Land-use Change on the Environment in SubAndean Amazonia, Peru
The aim of the study is to increase the understanding of how natural factors (geology, pedology, climate, hydrology) and land use (deforestation and farming) affect the chemical composition of soil, sediment and stream waters. The samples will be collected both in temporal and spatial dimensions in selected catchments, and the chemical analyses will be carried out in commercial and university laboratories in Peru, Canada and Finland. To achieve a holistic perspective on the effects of deforestation the study also includes an interview study focusing on farmer’s attitudes and perceptions to natural resources and environmental change. An important part of the overall strategy is to develop collaboration with local research institutes and universities.
The objective of this study is to enhance the current understanding on how deforestation and the subsequent land-use change affects the natural environment (water and soil) and the living conditions for farmers in the SubAndean Amazon. The environmental data (including results on behavior of potentially toxic metals, soil-nutrient losses and water-quality degradation) together with the sociological data (perceptions on resource degradation) will be an important asset for the planning of environmental sustainability and socioeconomic growth in this and similar regions.
Two catchments located in the SubAndean Amazon were selected as study areas. During the first round of field work water samples from 50 tributaries to the main rivers in these two basins were collected. The chemical compounds and elements were evaluated in respect to each other and to discharge, subbasin characteristics, lithology and land cover. The latter was produced by analysing optical remote sensing data. Historical water chemistry and geochemistry data are virtually non-existing in this region, thus, to study historical changes in geochemistry five vertical profiles of floodplain sediments were collected and analysed. The geochemistry of this sediment type has often been used for tracking natural and anthropogenic processes in catchments. In the current land practices (slash and burn agriculture) the soils capacity to carry crops rapidly decreases after deforestation. As a result 80% of the deforested area in this region is composed of secondary vegetation currently not used for agricultural production. A more effective way to cultivate the soils could be an important measure in reducing the extent of deforestation of virgin tropical forest. To investigate changes in soil quality when pristine forest is replaced, samples were collected from virgin forest and varying kinds of land use including successional forest, crops and pasture. The material is currently being analysed. The upcoming field study consists of an in-situ interview study focusing on farmer’s attitudes and perceptions towards natural resources and environmental change. Differences in opinions between the natives and the colonists will be analysed.
In the great Amazon basin there are still continuous and vast areas of primary forest that holds a unique biodiversity and an ecological and biogeochemical complexity largely unknown to man. The pressure from anthropogenic activities, however, results in an ever increasing extent of deforested areas. One of the regions experiencing the most severe deforestation is the Andean Amazon. The main reason for deforestation in this region is small scale sustenance agriculture which continuously increases due to population growth partly caused by migration from other regions. The Andean Amazon is, for several reasons, a very important part of the Amazon basin. According to Conservation International the Tropical Andes is the richest and most diverse region on Earth. Further, the Andean
Amazon is the main source of river-transported chemical and physical components in the downstream Amazon plain. Deforestation in the Andean Amazon has thus the potential to strongly affect the hydrochemical and hydrophysical characteristics of the Amazon River, its adjacent floodplain, and estuary.
The water chemistry in the study area is dominated by dissolution of carbonate rock with massive evaporitic deposits and variations in topography. However, an influence from deforestation cannot be ruled out, especially regarding potassium, dissolved oxygen and water temperature. We also have detected significant deviations, compared to background concentrations, of potentially toxic metals (e.g. Hg, Pb, Cd, Co, Ni, As) in the floodplain sediments. The origin of these metal peaks may be deforestation followed by increased surface erosion, causing a deposition of sediments enriched in organic material complexing atmospherically deposited elements. However, in-situ processes may also, partly or completely, have caused the accumulation of metals.
NOVA research and development platform, Sida, OASIS, Memory of Bengt Lundqvist’s Foundation, Helge Ax:son Johnsson’s Foundation, Futura Foundation, Carl-Fredrik von Horn’s Foundation
WWF-Perú, Amresam, Cedisa, Capirona, Emapa, Huallaga and El Dorado Municipality
Main Supervisor, Mats Åström
Assisting supervisors, Marianne Lindström, Pasi Peltola and Tommy Claesson
Curriculum Vitae – short
PhD candidate – Environmental Science, School of Natural Sciences, Linnaeus University.
M.Sc. Aquatic and Environmental Engineering, Uppsala University.
Supervisor of Master Students
Karin Olsson (Swedish University of Agricultural Sciences)-finished December 2008
Elin Sandström (University of Kalmar) -finished October 2008
Alexandra Röttorp (Uppsala University) -finished April 2009
Sara Lindgren (Uppsala University) -finished April 2009
Maria Persson (Uppsala University/Swedish University of Agricultural Sciences) – finished October 2009
Refereed journal articles
Lindell, L., Åström, M., Öberg, T., 2010. Land-use versus natural controls on soil fertility in the Subandean Amazon, Peru. Science of the total environment. 408:965-975.
Lindell, L., Åström, M., Öberg, T., 2010. Land-use change versus natural controls on stream water chemistry in the Subandean Amazon, Peru. Appl. Geochem. 25:485-495.
Lindell, L., Åström, M.E., Sarenbo, S., 2010. Effects of forest slash and burn on the
distribution of trace elements in floodplain sediments and soils of the Subandean Amazon, Peru. Appl. Geochem. 25:1097-1106.
Lindell, L., Åström, M., 2008. Los Efectos de la Agricultura de Tala y Quema sobre la Fertilidad de los Suelos de la Amazonia Subandina, Perú [abstract]. In: Proceedings of XI Congreso Nacional y IV Internacional de la Ciencia del Suelo; 2008. Nov 16-21; Tarapoto. San Martin, Peru. pp 114-117.
Lindell, L., Nilsson, K., 2002. Swedish Contribution to the Greenhouse Effect and Required Reductions to Meet the 550 ppmv Target, B 1497, Swedish Environmental Research Agency IVL, Stockholm.
Halmstad, S., Lindell, L., 2003. Estudio de Prefactibilidad de un Projecto de Riego en los Andes – el Caso de Balda Lupaxi Bajo, Chimborazo, Ecuador. Committee for Tropical Ecology, Uppsala University, Uppsala.
Lindell, L., 2004. Djupförvarsteknik. Grundvattenkemidata och grundvattennivåer för privata brunnar 2003. SKB TD-04-10. SKB, Stockholm.
Morosini, M., Lindell L., 2004. Compilation of measurements from manually gauged hydrological stations, October 2002 – March 2004. Oskarshamn site investigation. SKB P-04-246. SKB, Stockholm.