Smallholder rubber and swidden agriculture in Borneo: A sustainable adaptation to the ecology and economy of the tropical forest

This is a study of the role of Para rubber cultivation in a system of swidden agriculture in Indonesian Borneo. Such smallholdings produce most of Indonesia’s rubber, which is the country’s largest agricultural generator of foreign exchange. Rubber integrates well into Bornean systems of swidden agriculture: the comparative ecology and economy of Para rubber and upland swidden rice result in minimal competition in the use of land and labor — and even in mutual enhancement — between the two systems. Rubber occupies a distinct niche in the farm economy: it meets the need for market goods, while the swiddens meet subsistence needs. The intensity of production on these smallholdings is, as a result, characteristically low (and may even vary inversely with market prices). This reflects the independence of these smallholders from external economic and political influences, which has been the key to their historical success. The special virtues of such “composite systems” merit greater attention by development planners. Penilitian ini mempelajari peranan karet rakyat sebagai pasangan bagi sistem perladangan di Kalimantan-Indonesia. Perkebunan karet rakyat merupakan penghasil utama karet Indonesia, yang merupakan penyumbang pertanian terbesar bagi devisa negara. Karet rakyat membaur dengan baik dalam sistem perladangan di Kalimantan: pembandingan ekologi dan ekonomi antara karet rakyat dan sistem perladangan menunjukkan persaingan yang minimum dalam pemakaian lahan dan tenaga kerja—dan bahkan saling menguntungkan—antara kedua sistem tersebut. Karet rakyat menempati kedudukan yang penting dalam ekonomi usaha para peladang: yaitu memenuhi kebutuhan barang-barang pasar, sedangkan sistem perladangan memenuhi kebutuhan pokok hidup. Intensitas produksi perkebunan karet rakyat oleh karena itu, brasanya agak rendah (yang kadang-kadang berbeda berbalikan dengan harga pasar). Hal ini menggambarkan ketidak-bergantungan petani karet pada pengaruh-pengaruh ekonomi dan politik dari luar, dan ini merupakan kunci sukses mereka. Hal-hal khususyang menguntungkan dari sistem terpadu inipatut mendapatkanperhatian yang lebih besar dari perencana-perencana pembangunan.     

Fertilizers and biological nitrogen fixation as sources of plant nutrients: Perspectives for future agriculture

Biological nitrogen fixation (BNF) has an assured place in agriculture, mainly as a source of nitrogen for legumes. Legumes are currently grown mostly as a source of vegetable oil and as food for humans and animals, but not as nitrogen source.Other crops with BNF capability may be eventually be developed eventually. Such crops will also need mineral fertilizers to maintain a good status of soil nutrients, but their possible effects to the environment is also a concern. Fertilizers, however, will remain a necessary and sustainable input to agriculture to feed the present and increasing human population. It is not a case of whether BNF is better or worse than mineral fertilizers because both plays an important role in agriculture.     

我国三大城市群地区城市和农业用地地表热环境效应对比研究

以大中小城市协同发展为特征的城市群已成为我国城市化发展的主要形式，城市化和农业作为城市群地区最主要的土地利用活动，其气候效应是国际研究的热点。然而过去研究多关注大城市的热岛效应，对更为普遍的农业活动以及中小城市城市化的气候效应认识十分薄弱。基于MODIS地表温度数据，以自然林地为参照，提出了一种可逐像元估算土地利用地表热环境效应的新方法，进而对比分析了我国三大城市群地区（京津冀、长三角和珠三角）城市和农业用地地表热环境效应及其驱动因子差异。结果表明各城市群白天城市热岛效应明显，地级以上城市年平均热岛强度达3.2℃以上，但最强热岛均未发生在核心城市。夜晚热岛效应明显减弱，京津冀和长三角部分城市甚至出现冷岛效应。农业用地在白天亦表现出明显的增温效应，特别是在京津冀地区，而在夜晚除珠三角城市群外，降温效应明显，京津冀和长三角地区平均降温2.3℃和0.7℃。虽然城市用地平均增温强度大于农业用地，但农业用地因面积优势对区域温度变化起控制作用。白天城市和农业用地整体导致各城市群温度明显增加，京津冀增温最高（4.0℃），夜晚二者导致长三角和京津冀地区平均温度降低。研究还发现各城市群城市和农业用地地表热环境效应时空异质性极大，主要受植被、地表反照率、气候背景和人口密度控制。本文对制定缓解气候变化的土地利用策略具有重要的指导意义。     

Instructions for Authors

<正>Aims and scope SCIENCE CHINA Life Sciences(Sci China Life Sci)is a journal published monthly in English by the Chinese Academy of Sciences,and co-sponsored by the National Natural Science Foundation of China.It is published in both printed and electronic forms by Science China Press and Springer.The journal publishes high-quality papers from a wide range of areas in life sciences,including biology,medicine,and agriculture and ecology.Six categories of papers are published:Review,Research Paper,CUSBEA Article Series,Insight,Letter to the Editor,and News and Views.     

Isolation of microsatellite markers for Contarinia nasturtii,a European pest invading the New World

Microsatellite markers were developed for epidemiological studies on Contarinia nasturtii (Diptera, Cecidomyiidae), a native European pest that was introduced to the New World in 1996. Nine loci were found to be polymorphic and suitable for the analysis of 56 male individuals that were collected using pheromone traps. These markers all conform to Hardy–Weinberg expectations in at least one of the two tested populations, and carry an average number of 11 alleles among populations and observed levels of heterozygosity ranging from 0.32 to 0.86. Primers for all markers also successfully amplified fragments from Contarinia pisi and Contarinia tritici.     

Response of three lotic assemblages to riparian and catchment‐scale land use: implications for designing catchment monitoring programmes

1. Although many studies have focussed on the effects of catchment land use on lotic systems, the importance of broad (catchment) and fine (segment/reach) scale effects on stream assemblages remain poorly understood. 2. Nine biological metrics for macrophytes (498 sites), benthic macroinvertebrates (491) and fish (478) of lowland and mountain streams in four ecoregions of France and Germany were related to catchment and riparian buffer land use using partial Redundancy Analysis and Boosted Regression Trees (BRTs). 3. Lotic fauna was better correlated (mean max., r = 0.450) than flora (r = 0.277) to both scales of land use: the strongest correlations were noted for mountain streams. BRTs revealed strong non‐linear relationships between mountain assemblage metrics and land use. Correlations increased with increasing buffer lengths, suggesting the importance of near‐stream land use on biotic assemblages. 4. Several metrics changed markedly between 10–20% (mountain ecoregions) and 40–45% (lowland) of arable land use, irrespective of the buffer size. At mountain sites with >10% catchment arable land use, metric values differed between sites with <30% and sites with >30% forest in the near‐stream riparian area. 5. These findings support the role of riparian land use in catchment management; however, differences between mountain and lowland ecoregions support the need for ecoregion‐specific management.     

Tibetan land use and change near khawa karpo, Eastern Himalayas

Collaborating Authors: Bee Gunn, Wayne Law, George Yatskievych, Wu Sugong, Fang Zhendong, Ma Jian, Wang Yuhua, Andrew Willson, Peng Shengjing, Zhang Chuanling, Sun Hongyan, Meng Zhengui, Liu Lin, Senam Dorji, Ana, Liqing Wangcuo, Sila Cili, Adu, Naji, Amu, Sila Cimu, Sila Lamu, Lurong Pingding, Zhima Yongzong, Loangbao, Bianma Cimu, Gerong Cili, Wang Kai, Sila Pingchu, Axima, and Benjamin Staver.TIBETAN LAND USE AND CHANGE NEAR KHAWA KARPO, EASTERN HIMALAYAS. Economic Botany 59(4):312-325, 2005. Tibetan land use near Khawa Karpo, Northwest Yunnan, China, incorporates indigenous forest management, gathering, pastoralism, and agriculture. With field-based GIS, repeat photography, and Participatory Rural Appraisal we quantitatively compare land use between higher and lower villages, and between villages with and without roads. Households in higher elevation (> 3,000 meters) villages cultivate more farmland (z = -5.387, P ≤ 0.001), a greater diversity of major crops (z = -5.760, P < 0.001), a higher percentage of traditional crops, and fewer cash crops (z = -2.430, P = 0.015) than those in lower elevation villages (< 2,500 meters). Villages with roads grow significantly more cash crops (z = -6.794, P ≤ 0.001). Both lower villages and villages with roads travel farther to access common property resources. Historical analyses indicate agricultural intensification in valleys, an increase in houses, new crop introduction, hillside aforestation, cessation of hunting, glacial retreat, and timberline advance within the past century. We suggest that Tibetan land use reveals trade-offs between high, remote villages and lower villages near roads. Higher villages offer abundant land and access to natural resources but short growing seasons and little market access; in contrast, lower villages have road and market access, an extended growing season, and modern technology, but limited access to land and many other natural resources.