Biodiversity and Key Ecosystem Services in Agroforestry Coffee Systems in the Brazilian Atlantic Rainforest Biome
Total Page：16
File Type：pdf, Size：1020Kb
Biodiversity and Key Ecosystem Services in Agroforestry Coffee Systems in the Brazilian Atlantic Rainforest Biome Helton Nonato de Souza i Thesis committee Thesis supervisors Prof. dr. L. Brussaard Professor of Soil Biology and Biological Soil Quality, Wageningen University Prof. dr. I.M. Cardoso Department of Soils, Federal University of Viçosa, Brazil Thesis cosupervisors Dr. M.M. Pulleman Researcher, Department of Soil Quality, Wageningen University Dr. R .G.M de Goede Assistant professor, Department of Soil Quality, Wageningen University Other members Prof. dr. P. Kabat, Wageningen University Prof. dr. B.J.M. Arts, Wageningen University Dr. ir. J. de Graaff, Wageningen University Prof. dr. R.G.A. Boot, Utrecht University This research was conducted under the auspices of the C. T. de Wit Graduate School of Production Ecology and Resource Conservation ii Biodiversity and Key Ecosystem Services in Agroforestry Coffee Systems in the Brazilian Atlantic Rainforest Biome Helton Nonato de Souza Thesis submitted in fulfilment of the requirements for the degree of doctor at Wageningen University by the authority of the Rector Magnificus Prof. dr. M.J. Kropff, in the presence of the Thesis Committee appointed by the Academic Board to be defended in public on Wednesday 18 January 2012 at 4 p.m. in the Aula. iii Helton Nonato de Souza Biodiversity and Key Ecosystem Services in Agroforestry Coffee Systems in the Brazilian Atlantic Rainforest Biome Thesis, Wageningen University, Wageningen, NL (2012) With references, with summaries in Dutch and English ISBN 978-9461731098 iv Dedication To my mom, Maria das Graças (Gracita, in memoriam) who taught me to be brave, persistent without losing the sense of humanity. To my brother, Geraldo (in memoriam) who taught me that to pursue dreams we have to build our own way. v vi Abstract This thesis reports the results of longterm experimentation (since 1993) of family farmers with agroforestry (AF) coffee systems in the Brazilian Atlantic Rainforest region, a highly fragmented and threatened biodiversity hotspot. The farmers used native trees from forest fragments during a transition from the predominant full suncoffee (SC) production to more diversified agriculture. The aim of the research was to gain understanding of different agricultural management systems within the complex landscape matrix with respect to farmers’ capacity to diminish negative impacts on the environment, based on an ecosystem services approach. Participatory Rural Appraisal was used to obtain data from the family farmers. A method of systematization of their experiments created platforms for reflexion and development of agroforestry systems for farmers, technicians and researchers beyond only listing the negative and positive results. Longterm effects of coffee agroforestry (AF), full sun coffee (SC) systems and surrounding reference forest fragments (RF) were assessed on: tree biodiversity, microclimate, soil quality, costs of labour and inputs and profitability. Selection of appropriate tree species was essential to the success of agroforestry. The main criteria for selecting tree species by farmers were: compatibility with coffee, amount of tree biomass produced, diversification of the production and the labour needed for tree management. The farmers used 85 tree species across the area, 28 of which belonged to the Leguminosae, a family of nitrogenfixing plants. Most trees were either native to the biome, or exotic fruit trees. The diversification of production, especially with fruit trees, contributed to food security and to a low cost/benefit ratio of AF. Comparisons between reference forest fragments, agroforestry coffee and sun coffee revealed the potential of AF to conserve local tree biodiversity. Litter quality onfarm was functional in terms of soil erosion and fertility management. The canopy of the trees mitigated high temperature extremes: maximum temperature in SC systems (32oC) was 5.4 oC higher than in AF. Some soil quality parameters (total organic carbon, microbial carbon, soil respiration and potential nitrogen mineralization) showed higher values in RF than AF and SC, but no differences were observed between AF and SC. There was considerable diversity in the strategies and management of farmers for AF (including the choice of tree species), affecting the productivity and profitability. The total production value of AF was on average 43% higher than that of SC, largely due to other vii products than coffee. Both systems had an overall higher return of labour than the wage rate in the area. Continued participative work among scientists and stakeholders may help to increase the delivery of ecosystem services provided by family agriculture. Production systems based on ecosystem service delivery beyond just crop production have potential to reduce the need for external inputs and contribute to major local, regional and global objectives, such as food security, adaptation to climate change and conservation of biodiversity. viii ix Propositions (Stellingen) 1. Soil management in agroforestry is key to enhance ecosystem services at different scales (this thesis). 2. Diversity in agroforestry systems generates resilience (this thesis). 3. Using indigenous instead of exotic trees in agroforestry enhances the delivery of ecosystem services. 4. Sustainability will only be achieved when above- and belowground interactions in ecosystems become part of land managers’ collective awareness. 5. Agriculturalists and conservationists must learn from each other, including the mistakes made by both, to be able to inform society’s decisions on natural resource management. 6. Agroecology must be understood as a combination of science, practice and movement. 7. “The best things in life are free”. Propositions accompanying the PhD thesis ‘Biodiversity and Key Ecosystem Services in Agroforestry Coffee Systems in the Brazilian Atlantic Rainforest Biome’ Helton Nonato de Souza Wageningen, 18 January 2012 x xi Table of Contents Chapter 1 General Introduction ………………………………………………… 01 Chapter 2 Learning by Doing: a Participatory Methodology for Systematization of Experiments with Agroforestry Systems, with an Example of its Application 13 Chapter 3 Selection of native trees for intercropping with coffee in the Atlantic Rainforest biome ............................................................................................................ 37 Chapter 4 Protective shade, tree diversity and soil properties in coffee agroforestry systems in the Atlantic Rainforest biome ………..………………………………… 59 Chapter 5 Strategies and economics of farming systems with coffee in the Atlantic Rainforest Biome ………………………………..……………………… 87 Chapter 6 General discussion and Conclusions .......................................................... 110 References ……………………………………………………………………….…… 118 Summary …………………………………………………………………………….… 136 Samenvatting …………………………………………………………………………… 142 Acknowledgements ……………………………………………………………………… 149 Biography ………………………………………………………………………….…… 151 Education Certificate ……………………………………………………………….…. 153 xii Chapter One General introduction One of the challenges to society in areas with high biodiversity and a large human population is to develop agriculture that produces food and income to sustain rural livelihoods without further compromising biodiversity conservation. This raises the need to improve our understanding of the relations between biodiversity, agricultural production, resilience and equity in models of agriculture and land use. The overall objective of this thesis was therefore to obtain knowledge on agroforestry systems linked to ecosystem services. This chapter aims to give context to the current societal and scientific debate on the contribution of ecosystem services to the functioning of agroecosystems and the connection of biodiversity and human wellbeing, linking this to a case study in the Brazilian Atlantic Rainforest biome. 1. Common interests leading to a sustainable future Today’s challenge for society is to simultaneously achieve goals in the areas of food production, biodiversity conservation and sustainable natural resource management. In the context of an increasing global population, changing diets, climatic change, and environmental degradation, sustainability is gaining more and more urgency (Costanza et al, 1997; Evenson and Gollin, 2003; Tallis et al., Vandermeer et al., 1998). Continued climate change is foreseen to result in further biodiversity loss and to negatively affect production of agricultural goods, which in many cases poses an additional challenge to ecosystem management (Cincotta et al., 2000). The attention for food security, environmental protection, biodiversity, climate change, and the relations among them, is reflected in international policy frameworks, conventions and research efforts. These are, e.g., the Convention on Biological Diversity (CBD), the United Nations Convention to Combat Desertification (UNCCD), the reports of the Intergovernmental Panel on Climate Change (IPCC) and the Millennium Development Goals (MDGs) which aim at reducing disparities by eradicating hunger, poverty, child mortality, inequity between genders, lack of primary education and unhealthy conditions, all striving for environmental sustainability and forging a global partnership for development. An international scientific appraisal of the condition and trends in the world’s ecosystems has been conducted in the Millennium Ecosystem Assessment (MEA, 2003; MEA, 2005a). In order to stimulate scientific understanding