Stephen F. Siebert

Medicinal plant ecology, knowledge and conservation in Kalimantan, Indonesia

This study documents the abundance, distribution and knowledge of medicinal plant species in a Ransa Dayak village and adjoining forest in West Kalimantan, Indonesia. Over 250 medicinal plant species from 165 genera and 75 families are utilized by the local healer. Late successional, primary and river bench forests contained the highest diversity of locally-utilized medicinal species and the greatest number of species restricted to a single forest type for which alternative species or remedies were unavailable. Epiphytes and trees restricted to primary forests are particularly important sources for plants used to treat unusual ailments. A 100% survey of village residents 15 years of age and older (N = 32) revealed that people older than 25 years of age, and older females in particular, possessed greater knowledge of medicinal plants and their uses than younger people and males. All residents, except the male healer, were more knowledgeable about medicinal plants found in early successional forests than those of primary forests. Commercial logging and the loss of traditional knowledge through acculturation pose twin challenges to the persistence of traditional medicinal plant use in this Ransa village and throughout much of Kalimantan.RésuméPenelitian ini mengumpulkan informasi mengenai keberadaan, penyebaran dan pengetahuan tentang jenis tumbuhan obat di daerah perkampungan Daya’ Ransa dengan hutan sekitarnya di Kalimantan Barat, Indonesia. Lebih dari 250 spesies tumbuhan obat dari 165 genus dan 75 suku digunakan oleh dukun setempat. Hutan sekunder tua, hutan primer dan daerah hutan sepanjang pinggir sungai merupakan tipe hutan yang memiliki keanekaragaman dan jenis tumbuhan obat paling tinggi yang hanya tumbuh di tipe hutan tersebut serta tidak adanya jenis tumbuhan obat pengganti untuk mengobati penyakit yang sama di tipe hutan lain. Jenis epipit dan pohon yang ditemukan khusus di hutan primer mempunyai arti sangat penting bagi masyarakat karena digunakan untuk menogobati jenis penyakit yang tidak biasa. Dari survey 100% yang dilakukan terhadap penghuni desa yang usianya lebih dari 15 tahun (N = 32) diketahui bahwa penduduk yang berusia lebih dari 25 tahun, terutama perempuan berusia tua, mempunyai pengetahuan yang lebih banyak mengenai pemanfaatan tumbuhan obat dibandingkan dengan laki-laki dan perempuan yang lebih muda. Seluruh penduduk, kecuali sang dukun, lebih mengetahui pemanfaatan tumbuhan obat yang tumbuh di hutan sekunder muda dibandingkan dengan tumbuhan obat yang tumbuh di hutan primer. Kegiatan pembalakan hutan berskala besar (HPH) dan hilangnya pengetahuan tradisional lewat perubahan budaya adalah dua tantangan yang dihadapi untuk dapat mempertahankan pemakaian dan melestarikan tumbuhan obat di kampung ini khususnya dan di seluruh Kalimantan umumnya.

World Agriculture and Soil Erosion

A dequate food supplies depend on productive land. Soil erosion is a major environmental problem that threatens world food production (UNEP 1980). Today the human population is greater than ever before, and more people are malnourished (Swaminathan 1983). At present, one billion people are malnourished and the problem is growing rapidly (Latham 1984). Currently 97% of the worlds food supply comes from land rather than oceans and other aquatic systems (CEQ 1980). Therefore, the control of soil erosion for a sustainable agricultural system is essential to any program to improve world food security and development. Just at a time when agricultural efforts are focused on increasing crop yields, land degradation is increasing. The dimensions of land destruction

From shade- to sun-grown perennial crops in Sulawesi, Indonesia: implications for biodiversity conservation and soil fertility

Traditional, complex forest farming systems are increasingly convertedto sun-grown monocultures throughout the tropics. Biophysical, soil andbiodiversity effects associated with sun- vs. shade-grown coffee and cacao wereinvestigated in a case study in Sulawesi, Indonesia. Canopy height, tree,epiphyte, liana and bird species diversity, vegetation structural complexity,percent ground cover by leaf litter, and soil calcium, nitrate nitrogen andorganic matter levels in the O horizons were all significantly greater in shadedthan in sun-grown farms. In contrast, photosynthetic active radiation (PAR), airand soil temperatures, weed diversity and percent ground cover by weeds weresignificantly greater in sun compared to shade farms. At the landscape level,conversion of shade-grown crops to sun conditions isolates protected areas andremnant primary forest fragments. Local cultivators are cognizant of theagronomic and socioeconomic risks associated with sun-grown perennialmonocultures and some are increasing the density and diversity of fruit treecultivation in an effort to provide shade and organic matter, and increase anddiversify crop yields. The maintenance of traditional, complex forest farmingsystems, particularly shade-grown perennial crops, warrants greater attention inagricultural development and biodiversity conservation efforts.

Cultivating cacao Implications of sun-grown cacao on local food security and environmental sustainability

The reasons why upland farmerson the Indonesian island of Sulawesi areengaged in a cacao boom and its long termimplications are addressed in the context ofprotected area management regulations, andpolitical and economic conditions inPost-Suharto, Indonesia. In the remote casestudy village of Moa in Central Sulawesi, wefound that while few households cultivatedcacao in the early 1990s, all had planted cacaoby 2000. Furthermore, the vast majoritycultivate cacao in former food-crop focusedswidden fields under full-sun conditions.Farmers cultivate cacao to establish propertyrights in light of a land shortage driven inpart by the prohibition of farming and forestproduct collecting in a nearby national park,and to secure a future source of income, aconcern that has been exacerbated byIndonesias economic crisis. However,conversion of swidden fields to sun-grown cacaoconstrains future food productionopportunities, increases susceptibility todrought stress and potential soil nutrient andorganic matter losses, and increases householddependence on a commodity that is subject toextreme price volatility. These factors raisesignificant concerns for local food securityand agricultural sustainability.

Forest-product trade in a lowland Filipino village

Forest-product use among nonforest dwelling cultural groups in Southeast Asia is not well known, particularly in contrast to what is known about indigenous forest-product collectors. A case study in one lowland Filipino village in Leyte, Philippines, revealed that over half of village households depend upon 8 species of commercially valuable rattan and 8 species of timber as a primary source of livelihood, and that all village households collected forest-products for supplementary and emergency income. The future of the rattan and timber trade on Leyte is seriously threatened by agricultural encroachment and intensive collecting pressures in the absence of forest management.

Land use intensification in tropical uplands: Effects on vegetation, soil fertility and erosion

Abstract Impacts of intensified hillside farming on land use patterns, vegetation cover, soil nutrient status, and erosion were evaluated in the Bayhang River watershed, Leyte, The Philippines. Forests in the Bayhang watershed provide subsistence food and income to landless lowlanders, primarily through forest product collecting and food and cash-crop cultivation. Unregulated forest product collecting has depleted mature, commercially harvestable rattan and hardwood species (e.g., Calamus spp., Dipterocarpaceae and Pterocarpus indicus ) throughout the watershed. Intensified agricultural activities (i.e., shortened swidden fallow cycles) have led to a depauperate, largely exotic, xerophytic flora dominated by Imperata cylindrica, Saccharum spontaneum and various Compositae. Continuous cultivation of corn and sweet potato gradually exhaust soil calcium, magnesium, available phosphorus, and organic matter levels and increase soil acidity. However, soil nutrient and physical characteristics appear to decline more slowly under sweet potato monocropping than under corn + sweet potato relay intercropping. An average of 3.3 cm (± 3.1 cm) of soil (approximately 489 metric tons per ha) eroded from hillside farm study plots during the first 6 months of cultivation. Sustainable and productive forest gathering and hillside farming activities that incorporate existing land use practices are reviewed, including: the cultivation of rattan in farms and forests, the introduction of agronomic soil conservation measures, and the construction of agroforestry countour bunds and drainage ditches.

Traditional Agriculture and the Conservation of Biological Diversity in Crete, Greece

The biological diversity in traditional agroecosystems and potential diversity loss associated with land use change in upland Crete was investigated. Using transects, plots and point count sampling methods, the dominant vegetation types and land uses, floristic diversity, breeding birds, and key biophysical attributes of remnant traditional agroecosystems in three upland catchments were identified. Eight vegetation/land use types were observed, including: chestnut stands, old olive groves, maquis, phrygana, intensively cropped parcels, rock walls and hedges, woodlands, and intensive olive groves. Eighty-three native plant species in traditional agroecosystems were recorded, the majority of which were shade intolerant perennial herbs and shrubs adapted to grazing and browsing. The vegetation types/land uses were distributed in a complex mosaic across the landscape, exhibited a wide range of light conditions, structural attributes, percent ground cover, soil organic matter levels, and provided breeding habitat for at least 19 bird species. Traditional farming, grazing and forestry are declining throughout the northern Mediterranean. Woodlands and intensive olive monocultures have replaced diverse land use mosaics and contain less biological diversity than traditional agroecoystems. The conservation of Mediterranean floristic diversity necessitates understanding disturbance regimes and may require maintaining the land use practices and mosaics associated with traditional cultivation practices and livestock grazing.

The abundance and site preferences of rattan (Calamus exilis and Calamus zollingeri) in two Indonesian national parks

Abstract The abundance and site preferences of Calamus exilis and Calamus zollingeri were studied in primary forests of Kerinci-Seblat National Park and Dumoga Bone National Park, Indonesia, respectively. Forty sample plots, each 0.05 ha in size, were established at random in principal rattan collecting areas in both parks. In each plot the number of rattan plants and canes, predominant light regime, soil nutrient characteristics and soil drainage patterns were measured. An average of 284 C. exilis plants with 191 mature canes and 1910 m of harvestable cane were observed per hectare in Kerinci-Seblat National Park. An average of 38 C. zollingeri plants with 86 mature canes and 2660 m of harvestable cane were observed per hectare in Dumoga Bone National Park. Populations of C. exilis (number of plants and canes) were negatively related to high light intensities. Conversely, populations of C. zollingeri (number of plants and canes) were positively related to high light intensities, specifically those associated with gaps in the forest canopy. Implications of rattan abundance and light preferences for cane harvesting and forest management are discussed.

Agricultural Change in Bumthang, Bhutan: Market Opportunities, Government Policies, and Climate Change

Interviews with elderly farmers and a review of government data, policies, and programs reveal that farmers in the Bumthang District of Bhutan have transitioned from cultivating a diversity of subsistence grains through swidden farming with no external inputs in the 1980s to intensive monocropping of potatoes utilizing fertilizers and tractors in 2011. During the same time, household diets changed from locally cultivated buckwheat and barley to make greater use of purchased rice. The primary underlying driving forces noted by farmers for the changes were improved road and market access, and government prohibitions against swidden agriculture. Farmers also stated that climatic conditions have changed; however, temperature and precipitation data do not reveal significant change, although the variability of mean monthly precipitation has increased. Understanding the site- and time-specific ways in which farmers respond to underlying forces is essential to the identification and development of effective agricultural policies, research, and development.

Tree cutting to float rattan to market: a threat to primary forests?

Cutting small trees to float bundles of rattan cane to market is widespread in Indonesia and is purported to adversely affect primary forests and biodiversity conservation. I monitored rattan cane harvesting, tree species used as floater logs, and the locations and volume of floater log cutting in two forest villages adjacent to Lore Lindu National Park in Central Sulawesi, Indonesia for two years. During this period, an average of 135 and 100 tons of commercial rattan cane, primarily Calamus zollingeri, was harvested annually from the two villages, respectively. Floating cane to market required approximately 2350 and 1667 logs (each 3 m in length and 15-20 cm in diameter) or about 1175 and 834 trees annually in the two villages. Eight tree species were regularly used as floater logs and all were light-weight, fast-growing, pioneer species. Floater logs were harvested from fallowed shifting cultivation fields and naturally disturbed riparian flood plains. Over the two year study period, there was little floater log cutting in primary forests either inside or outside of the national park. The use of early successional tree species to float rattan to market does not appear to adversely affect primary forests or protected area management in this region.