Browsing by Subject "Lokales Wissen"

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Reconciling indigenous and scientific ecosystem and soil fertility indicators in swidden systems of Northern Thailand
(2021) Tongkoom, Krittiya; Cadisch, Georg
Crop rotations in today’s swidden systems of Northern Thailand typically include five to ten years of fallow. Regarding ecosystem functions, these systems are relatively close to secondary forests when compared to modern agricultural systems; but they are under pressure for intensification, i.e. shortened fallow periods. In general, criteria are needed to decide whether fallow duration can be reduced, safeguarding ecosystem restoration and provision of food and income for farmers. Acknowledging that a comprehensive assessment would cover multiple aspects, our study focuses on the role of fallow duration on tree community succession and use abundances of tree species considered as soil fertility indicators. We studied recovery indicators of tree communities at two potential broad-leaved forest climax sites that differ in soils, forest type and agricultural intensification: An intensive system of one-year upland rice, then one- to two-year maize cultivation with synthetic inputs followed by six years fallow; and an extensive system with one-year upland rice cultivation without agrochemicals and ten years fallow. In a case study village of extensive site, we investigated in how far abundance of indicator tree species corresponded to measured soil fertility parameters and whether an extended list of indicator species could improve prediction of these soil properties. Contrasting systems were chosen to test the applicability of our indicators, not to compare their management practices. From 2010 to 2011, eight variables related to stand structure and tree diversity and four soil properties were either monitored or surveyed in chronosequence plots representing different fallow ages. For each variable, means per fallow year were compared by least squares means (LS-means), and quadratic regressions from mixed models were fitted. Significant differences between LS-means and optima of regressions served to distinguish fallow stages and served as indicators of recovery and system stability. Stepwise multiple regressions confirmed fallow age as main determinant for most variables. Tree species indicator also identify by the component of multiple linear regressions function of each interested soil properties. Numbers of tree species and diversity index recovered to levels of the previous rotation within the respective fallow time, but in both systems were far from climax communities, probably due to seed-bank depletion and shift toward resprouting species. While species dominance changed over time in the extensive system, the intensive system was dominated by a single species. In the extensive system only tree density passed a peak during the fallow period, while biomass-related variables approached plateaus. In combination with the replacement of early fallow species, this points to the onset of competition and transition between successional stages. For the intensive system, no structural variable passed a maximum. With only one of eight indicators on the extensive site fulfilling the statistical criterion of passing a peak during the prevailing fallow time, reducing fallow periods is not recommended for our cases. Generally, combining LS-means and quadratic regression allowed assessing fallow duration based on distinct successional stages at different sites. The approach should include various relevant site-specific indicators, in our case representing biomass and carbon storage, species and structural diversity, considered crucial for both sites. From interview on the extensive site, farmers listed 11 tree species that relate to certain soil quality related properties. They named indicators of good soils for cropping, inappropriate soils for upland rice cropping and hard soils. Botanical tree inventories on 135 plots of one to ten years fallow age were conducted. Abundances of farmers’ indicator on one hand as well as inventory species on the other were introduced into different regression models to predict soil fertility parameters measured on the same plots. Both models were then compared regarding predictive power. Measured fertility parameters such as soil organic matter (SOM), pH, plant available phosphorus (Pav) - related to farmers’ criteria ‘good soil’ or inappropriate for rice cropping’ - as well as bulk density (BD, for ‘hard soil’), changed significantly during the fallow period, initially towards temporary pessima in years 6 to 7 followed by recovery towards year ten. Most indicator species, like Macaranga denticulata for Pav or Dalbergia cultrata for SOM, were clearly related to the soil quality characteristics attributed to them by farmers. Only in one case a species used as farmer indicator for hard soils was selected by multiple regression as predictor for high Pav. Including all tree species found during inventories into multiple regressions significantly improved predictions of measured soil parameters by AIC > |2|. Ten additional species from the survey model had potential to improve the farmer indicator model. Relative density, i.e. abundance of indicator tree species over abundance of all species, did not always match soil properties dynamics, so that the use of the regressions appears more informative for cropping decisions. Our approach to relate indicator species and measured soil parameters is not site-specific, but parameters are. Applicability of the approach could be extended if further farmer criteria such as weed suppression, represented by tree structure parameters as predictors of adequate fallow age, would complement soil fertility indicators. Based on the development of the multiple indicators of recovery of ecosystem services and soil fertility, it is not recommended to reduce fallow age at the two investigated study sites.
Recording, validating and scaling up local ecological knowledge of ethnic minority farmers in Northern Thailand and Northern Laos
(2015) Choocharoen, Chalathon; Hoffmann, Volker
Conceptually, local knowledge is recognized and investigated by a wide array of disciplines, and the focus has shifted from definition of ‘indigenous’ or ‘traditional’ knowledge to a perception of local knowledge as a dynamic concept and a principal basis for decision-making processes. This enables the creation of a research environment that is conducive to participatory approaches seeking to bridge the division between local and scientific knowledge. This thesis explains how local knowledge systems are composed by different know-ledge types, such as practices and beliefs, values, and worldviews. The knowledge systems change constantly under the influence of power relations and cross-scale linkages both within and outside the community. Likewise, local knowledge and practices need to be understood as adaptive responses to internal and external changes which result e.g. in disaster preparedness or sustainable growth of livelihoods at the local level. This thesis is based on interviews and using PRA tools about local knowledge and practices and attempts to give an overview and framework of local knowledge in sustainable land use and an understanding of the benefits and problems involved. Local knowledge systems (LKS) are an important part of the lives of the poor. They are the basis for decision-making of communities in food security, human and animal health, education, and natural resource management. LKS point to how indigenous people manipulate their knowledge, which has accumulated, evolved and practiced for generations. They epitomize the relationship and interaction between local peoples and their natural surroundings. In the study shown in paper I (Chapter 4), results based on group discussions shows farmers use 6 out of 8 scientific soil classifications. Through participatory soil mapping exercises, it was sought to develop a single, comprehensive soil classification reflecting the main soil types in the village territory. This process helped to explore the potential for using local soil classification towards regional soil mapping. It was concluded that the comparison of scientific soil classification and soil survey maps with local knowledge of soils can generate valuable synergies through integrating the perceptions of soil properties of scientists and farmers. Moreover, villagers in this research area will be able to have alternative or complementary options to grow plants and to generate improved revenues in the future. In paper II (Chapter 5), it was found that traditional silvopastoral systems are a key component of sustainable forest management. Forestry and forst use is a part of the established activities of upland farmers, who show interest in sustainable management and utilization of their natural resources. Local farmers knowledge has been so far excluded from governmental development policies. A country comparative analysis shows similar strategies of farmers but different (promoting / prohibiting) national policies. Local ecological knowledge about sylvo-pastoral systems can provide useful resources for striving towards more sustainable highland agro-ecosystems, if it is integrated into scientific analysis and policy making. Paper III (Chapter 6) found that cardamom plantations/collections are considered as an effective approach to poverty alleviation and sustainable rural development under conditions of increased resource scarcity in the uplands of Northern Laos. The analysis of the value chain revealed various potentials for development. The main policy implication is that protecting the remaining of natural and secondary forests, for instance through making use of evolving international support mechanisms for community based forest protection including REDD-plus, will not only be of advantage for biodiversity conservation and climate change mitigation, but would also improve the livelihoods of the poorest in the uplands of Northern Laos. The challenge for national resource managers is to combine the management of agricultural functions with ecological benefits through sustainable agriculture practices to enhance the livelihoods of local people. Local ecological knowledge can offer proven alternatives and complementary explanations of ecological cause-and-effect relationships. It may prove useful in further scientific investigation and can be utilized as a cross-reference with other findings and therefore contribute to sustainable resource management and improve the quality of local resources and livelihoods.