Productivity of Sumatran sheep, in a project integrating sheep and rubber plantations, was analyzed from 1985 to 1988. Ewes that had more than three lambings and managed under continuous exposure to rams had a nonseasonal distribution of lambings. Ewe weights averaged 22 kg at lambing and weaning, and were influenced (P < 0.01) by parity, nutrition and litter size. Repeatability of ewe weight at birth and weaning was 0.73 and 0.70, respectively. Lamb birth weights (1.8 kg) and weaning weights (9.3 kg), were heavier in male offspring (P < 0.01) and in small litters (P < 0.01). Litter size averaged 1.54 and its repeatability 0.32. Survival of singles (92%) and multiples (74%) were different by years (P < 0.01). Litter size and survival of multiples were affected by nutrition and ewe weight (P < 0.01). Weights of lambs born (2.74 kg) and weaned (11.45 kg) were significantly related to litter size and ewe weight. Weaned lamb output by ewes raising singles was 34–61% of those raising multiples. Repeatability of weights of lambs born and weaned was 0.38 and 0.36, respectively. Lambing interval averaged 201 days and repeatability 0.06. Parity, season, year and treatment had significant effects on lambing intervals. With a production rate of 1.82 lambings and some ewes weaning 3.6 lambs weighing 31.9 kg per 22 kg ewe per production year, Sumatran sheep have exceptional potential for accelerated lambing in integrated sheep and rubber plantation systems and humid tropical conditions.
Tag: hevea brasiliensis
Socially constructed rubber plantations in the swidden landscape of southwest China
The contribution of agroforestry systems to reducing farmers’ dependence on the resources of adjacent national parks: a case study from Sumatra, Indonesia
There is much debate about the way conservation and development are best integrated to reduce the encroachment pressures of poor rural communities on the biodiversity resources of protected areas in the tropics. One frequently recommended instrument is to intensify farming systems in the adjacent areas, so as to decrease the need to harvest resources from national parks. This study examined this issue by analyzing the effects of different household land uses in villages near a national park on their propensity to harvest resources from the park. In the northern part of the Kerinci Seblat National Park (Sumatra Island, Indonesia) the park buffer zone is comprised largely of community or village forests and human settlements. The village forests were formerly managed as production forests and provided significant cash income to the village. They were converted into farmland, particularly to mixed-tree gardens or agroforests. Natural forest coverage has now declined to 10% of the former area within village forest land. We analyzed the characteristics of the mixed gardens and village forests, and their practical contribution to reducing farmers’ dependence on the adjacent national park resources. Households with farms that were more diversified were found to have much less dependency on the national park resources. Households that farmed only wetland rice fields registered the highest value of forest products obtained from inside the park. Households that farmed only mixed gardens had an intermediate level of park resource extraction, while those that had farms composed of both components (i.e. wetland rice fields and mixed gardens) had a dramatically lower level of economic dependency on park resources than households in either of the other two categories.
On-farm evaluation of the establishment of clonal rubber in multistrata agroforests in Jambi, Indonesia
Perennial tree crops are often grown in complex multistrata systems that incorporate natural vegetation. These systems contribute simultaneously to sustaining rural livelihoods and to the conservation of biodiversity, but their productivity is usually low. Introduction of high yielding germplasm, usually selected in monocultural plantations, is a potential way to increase productivity, but a critical requirement is that such plants can be established in a competitive multispecies environment. The establishment of clonal planting stock in the jungle rubber agroforests of Indonesia was explored through participatory on-farm research. The trial involved four farmers who grew clonal rubber trees in a total of 20 plots, constituting five replicate experimental blocks spread across four farms. Unexpectedly, vertebrate pest damage by monkeys (Presbytis melalophos nobilis) and wild pigs (Sus scrofa) was the most important influence on establishment, explaining almost 70% of the variation in rubber tree growth. The amount of labour invested in weeding was also positively correlated with rubber tree growth. Farmers generally decided to completely cut back vegetation between rows of rubber trees, including potentially valuable trees, rather than weeding within the rows and selectively pruning trees in the inter-row. Farmers thought that the inter-row vegetation would harbour vertebrate pests and compete with the clonal rubber, and they had access to fruits, firewood and other non-timber forest products from other land. Thus, contrary to expectations, when offered clonal germplasm, farmers opted to use plantation monoculture methods to protect what they considered a valuable asset, rather than maintain the traditional multispecies strategy they use with local germplasm.