In Sumatra, small-scale farmers in particular play a key role, according to a study on the conversion of rainforests into monocultures and their effects
Oil palm plantations as far as the eye can see. In addition to a dramatic loss of many animal and plant species, such plantations often lead to massive environmental problems. Small-scale farmers in the tropics are also converting from traditional cultivation of their land to economically more attractive land use systems such as these oil palm plantations. A recent study by 41 researchers now shows for the first time the economic-ecological trade-offs of these developments for Indonesia's oil palm landscapes. There, the conversion of forest and agroforestry systems to rubber and oil palm monocultures has led to significant increases in income for the small farmers. "However, this has led to a dramatic loss of species diversity," said the first author of the publication, Prof. Dr. Ingo Graß from the University of Hohenheim in Stuttgart. One solution to the dilemma could be changes in economic incentive structures, such as certification of sustainable cultivation practices.
Tropical rainforests are among the most species-rich habitats on our planet, but they are seriously threatened as agriculture spreads and intensifies. In recent years, environmental protection organizations and the media have focused on the constantly growing, large plantations, especially those of oil palms.
"However, it is small farmers with farms between 10 and 20 ha in size who cultivate the largest part of the agricultural land in many tropical regions," explained Prof. Dr. Graß. Although these smallholders strongly influence the landscape, the social, economic, and ecological consequences have not yet been studied in detail.
In an interdisciplinary study by the Universities of Göttingen and Hohenheim together with Indonesian partner universities as part of the Collaborative Research Center 990 "EFForTS" funded by the German Research Foundation (DFG), the economic-ecological trade-offs of these developments for Indonesia's oil palm landscapes have now been examined for the first time.
In recent decades, the lowlands of the Jambi province in Sumatra, Indonesia, have been transformed from a densely wooded landscape to a landscape dominated by rubber and oil palm plantations. Prof. Dr. Graß illustrated the extent of the problem: "While in 1990 about 50% of the area was still covered with rainforest, in 2013 it was only 35%. This trend is ongoing and has far-reaching consequences for humans and the environment."
Small-scale farmers significantly improve their income if they convert from traditional forest and agroforestry systems, in which various plant cultures grow together with trees on the same area, to rubber and oil palm monocultures. This is not only because oil palm fruits can command significantly higher market prices than other crops, but also because monocultures are easier to manage.
"In addition, the oil palm is about three times more productive than other oil fruits such as soy," explained Prof. Dr. Graß. "However, while the small-scale farmers in our study region cultivate about 61% of the area used for oil palms, they produce only 40% of the total amount of oil.”
This has dramatic consequences for biodiversity, affecting both above-ground and underground organisms. Thousands of different species can be found in an intact rainforest on Sumatra, ranging from bacteria, fungi, and worms to trees, insects, birds, and bats, but over 90% of the species have disappeared in the monocultures.
These monocultures also have a significantly reduced functionality. The soil, which lacks nutrients and species diversity, can store significantly less of the greenhouse gas CO2, while nutrients and pollutants can be more easily washed out and thus enter groundwater and rivers. As a result, wells and rivers become unusable as sources of drinking water because the water is contaminated with nitrates and aluminum, for example.
Not only biodiversity is threatened, however. The development towards small-scale monocultures also leads to social changes.
Those who have land on which oil palms can be grown are significantly more prosperous than people without sufficient knowledge or access to land and resources. The authors of the study fear that this poses a potential for conflict because the gap between rich and poor is growing.
So what would be a feasible solution? "There are many ideas, but they must be feasible for the respective region and accepted by the people," said Prof. Dr. Graß. At the same time, it must be possible to solve the dilemma between the preservation of biodiversity and the highest possible income for small farmers. On a national level, the oil palm boom since 2000 has lifted an estimated 2.6 million rural Indonesians out of poverty.
To this end, the team of authors simulated different types of land use on the computer to determine how much profit can be generated in the respective landscape and how many species can be found there. Using an optimization algorithm, they were able to determine which form of land use leads to the highest possible biodiversity for a given profit.
This resulted in landscape compositions that mitigate some of the conflicting objectives of optimal land use allocation. "Ideally, small-scale farming landscapes consist of a mosaic of forest fragments, agroforestry, monocultures, and settlements that have the potential to combine high yields and high species diversity," explained Prof. Dr. Graß.
However, the simulations show that landscapes dominated by intensive monocultures always lead to higher profits for small-scale farmers. In fact, the oil palm monoculture is the best way to make the highest possible profit from a small amount of land. However, in order to keep the loss of biodiversity and ecosystem functions to a minimum, compensatory areas must exist where the rainforest remains as natural as possible.
For the team of authors, new economic incentive structures aimed at sustainable land management are therefore urgently needed. These can be, for example, officially supported measures, such as an obligation to leave rainforest islands within monocultures, or premium prices for products manufactured using environmentally friendly methods, such as rubber or palm oil from certified landscapes. "Initial talks with local authorities are already underway," said Prof. Dr. Graß.
EFForTS is a collaborative research center funded by the German Research Foundation (DFG) that investigates the ecological and socio-economic effects of the transformation of forests into a crop-dominated landscape with rubber and oil palm plantations in the lowlands of Sumatra. It is based on research work carried out in the province of Jambi with a focus on small-scale farming systems.
More than 160 researchers from the Universities of Göttingen and Hohenheim in Germany and the Indonesian universities IPB University (Bogor), UNTAD (Tadulako University, Palu), and UNJA (University of Jambi) are working closely together in the EFForTS project. They represent a wide range of disciplines, including ecology, forestry, agriculture, remote sensing, economics, human geography, and cultural anthropology. BACKGROUND: Science Year 2020 Bioeconomy
In 2020, the Science Year will be dominated by the bioeconomy - and thus by a sustainable, biobased economy. The aim is to produce and use natural materials and resources in a sustainable and innovative way, replacing fossil and mineral raw materials, manufacturing products in a more environmentally friendly way, and conserving biological resources. This is more necessary than ever in times of climate change, a growing world population, and a drastic decline in species. The Bioeconomy Science Year, organized by the Federal Ministry of Education and Research (BMBF), puts the topic in the spotlight.
Bioeconomy is the leading research topic at the University of Hohenheim in research and teaching. It links the Faculty of Agricultural Sciences, the Faculty of Natural Sciences, and the Faculty of Business, Economics and Social Sciences. During the Science Year on Bioeconomy, the University of Hohenheim is hosting many events to inform the public and experts on the topic.