Community Studies in Latin America

Revolt Against the Dead: The Modernization of a Mayan Community in the High- lands of Guatemala. Douglas E. Brintnall .
Agrarian Reform and Peasant Economy in Southern Peru. David Guillet .
San Rafael: Camba Town. Ally MacLean Stearman .     

Community Based Fisheries Management and Fisher Livelihoods: Bangladesh Case Studies

Poor fishers in Bangladesh have been disadvantaged by policies that favored powerful people leasing fishing rights. Community-based management was expected to improve fisher access, livelihoods, and the sustainability of fisheries. The impacts of community management in three floodplain waterbodies differed according to the environment and property rights. Where a set of fishers jointly held exclusive rights to a small enclosed lake they increased production by stocking fish and shared the returns. This strategy is productive but attracts competition for profits and fish consumption was unchanged. Access to capture fisheries in floodplain waterbodies enables the poor to catch diverse small fish for their consumption. Yet sustainability requires limits on fishing. Fish sanctuaries were respected, yet catches per day fell when more people from several villages increased fishing effort in a large wetland, while a tightly knit community restored the fishery in a smaller floodplain. Community organizations will need recognition of their long-term use rights to overcome future threats.

Community Resilience in Southern Appalachia: A Theoretical Framework and Three Case Studies

A fundamental assumption in nearly all research on social adaptation to environmental change is that there is a concomitant and inverse relationship between human communities’ dependence upon particular natural resources affected by environmental change and those communities or societies’ resilience to disturbances. However, recent theoretical and empirical developments suggest resilience is a dynamic social process determined, in part, by the ability of communities to act collectively and solve common problems. The interactional approach to community is utilized to develop a framework whereby various patterns of social interaction define the process of social resilience. Data come from multiple mixed methods case studies of forest dependent communities within Southern Appalachia. The findings reveal varied processes of social resilience can occur in communities with similar levels of resource dependence; a community’s composition of internal social ties and their cross-scale linkages to external agencies and organizations define these processes.     

协作与包容——新加坡锦簇社区计划解析

社区花园是公众共建、共享城市绿化的重要实践。当前中国社区花园建设正迅速开展,责权明晰的管理日益重要。选取新加坡锦簇社区计划为案例,基于文献分析与实地调研,探析新加坡社区花园建设的管理机制。研究发现位于公共组屋的社区花园采用“政府—社区”协作式管理机制,国家公园局、市镇理事会、居民委员会与居民等多元主体协作承担在园艺计划审批、花园选址、花园规划和建设过程中的系列职责,遵循机会平等、参与治理、共享成果的基本原则,促进了包容性社区的建设。其经验主要包括：政府积极引导,中间层级有效衔接;建立弹性的管理规则;以民为主,公平共享。     

井冈山自然保护区福建柏群落的研究

对井冈山福建柏(Fokienia hodginsii)群落4个样地的物种组成、区系成分和物种多样性进行了统计和分析.结果表明:该群落有维管植物32科43属59种,其中蕨类植物有4科4属5种,裸子植物3科3属3种,被子植物25科36属51种.区系分析显示该植物区系起源古老,地理成分复杂,以温带性成分为主,热带亚热带成分占有较大比例.群落为复层异龄结构,类型有福建柏 甜槠(Castanopsis eyrei)群落、福建柏 猴头杜鹃(Rhododendronsimiarum) 甜槠群落.群落物种多样性指数较高,各样地间多样性指数变幅不大;福建柏群落的4种多样性指数基本表现出相同的趋势,福建柏群落物种多样性在群落不同层次的变化规律为:灌木层>乔木层>草本层.     

Experimental and Ecological Studies on the Rubber-tea Artificial Community

This paper sums up the ecological data recorded in the south of Yunnan on our experiment of the rubber-tea artificial community during 1960 to 1980. It is a part of our studies of the tropical artificial ecosystem. The following results concern its dynamic productivity, stability, interspecific relationships, structure and function. 1. By the introduction of tea into the rubber plantation, its annual productive period has been prolonged from seven to ten months, while the non-productive period of young plants has also been shortened by three to four years. Its monthly productivity curve shows a change corresponding to the monthly variation of local solar radiation. In contrast, the monthly productivity curve of the monocultural tea plantation is not so. This is due to the fact that a tea-plantation must possess a certain amount of shade before it can grow well. 2. The rubber-tea community has a comparatively high stability in productivity. Low temperature is the major problem of rubber plantations in the south of Yunnan. It often causes cracks in the root collar barks of rubber trees and may even cause the death of the trees. We believe that the problem is caused by lack of heat from sun light, and have found that the critical least amount of heat necessary is 123 calories/sq em per day. In order to obtain more amount of heat, during the past twenty years, we have compared the annual productivity variations of various rubber-tea community structures, and are convinced that the cold-resistant ability of one kind of rubber-tea community structure has been greatly improved. This is achieved by discovering and applying two kinds of heat effects; namely, the directional heat effect of side rows and the lower story heat effect in the community. By adopting the wide row and thick planting structure of rubbertea community, arable land suitable for the rubber tree has been raised from 800 m. to 1000 m. in altitude. 3. The rubber-tea community possesses a high environmental protection capability. Owing to the introduction of the tea plants in the lower story, the annual rate of water loss in the community decreases by 42%, and that of soil erosion by 23.8%. Before the dry season sets in, the rubber-tea community contains 150 tons more water per hectare than that of a rubber plantation, and 322.5 tons more than that of a tea plantation (2.2 m thickness of Soil). The content of the organic matter in the soil of the rubber-tea community is 0.15% higher than that of a rubber plantation, and 0.2% higher than that of a tea plantation. Moreover, the soil unit weight of the rubber-tea community is comparatively lighter. 4. A corresponding relationship of the underground story-formation has been found in rubber-tea community; for example, rootlets of the rubber trees are concentrated in soil 0–20 cm below the surface, and those of the tea trees in soil 20–50 cm in depth. This shows the possibility of mutual aceomodation of the two species. 5. In conformity with the changes in altitute and latitude, the proportion of rubber and tea should also be changed accordingly. In the plains, the rubber trees will play a dominant part in the community. As the altitude rises, tea trees will gradually replace the rubber trees in playing the dominant role. Finally, the rubber trees entirely disappear from the scene and are replaced by plants such as camphor tree (Cinnamomum porrectum (Roxb.) Kosterm.). A camphor-tea community is formed. In fact, it is a type of artificial community welcomed by people in the south of Yunnan. Now, rubber-tea community is being rapidly spread in the southern part of our country, amounting to more than 10,000 hectares in area.     

A Framework for Australian Studies: Some Reflections on Community,Class and Culture

Community studies as a form of study in complex societies cart be unduly restrictive though this need not be the case. It depends on the criteria employed to select a field location, and on the types of social organization studied within that location. These themes are illustrated by reference to the Australian community studies of Ron Wild and Harry Oxley. Some limitations in their studies are noted only in order to illustrate how their work might have been linked profitably with debates in Australian historiography over issues of class culture, ideology and consciousness. I propose a framework for Australian community studies that would allow anthropologists to explore some of the themes introduced in this discussion.     

Investigation of an Iron-Oxidizing Microbial Mat Community Located near Aarhus, Denmark: Laboratory Studies

We constructed a small flow chamber in which suboxic medium containing 60 to 120 μM FeCl₂ flowed up through a sample well into an aerated reservoir, thereby creating an suboxic-oxic interface similar to the physicochemical conditions that exist in natural iron seeps. When microbial mat material from the Marselisborg iron seep that contained up to 10⁹ bacterial cells per cm³ (D. Emerson and N. P. Revsbech, Appl. Environ. Microbiol. 60:4022-4031, 1994) was placed in the sample well of the chamber, essentially all of the Fe²⁺ flowing through the sample well was oxidized at rates of up to 1,200 nmol of Fe²⁺ oxidized per h per cm³ of mat material. The oxidation rates of samples of the mat that were pasteurized prior to inoculation were only about 20 to 50% of the oxidation rates of unpasteurized samples. Sodium azide also significantly inhibited oxidation. These results suggest that at least 50% and up to 80% of the Fe oxidation in the chamber were actively mediated by the microbes in the mat. It also appeared that Fe stimulated the growth of the community since chambers fed with FeCl₂ accumulated masses of either filamentous or particulate growth, both in the sample well and attached to the walls of the chamber. Control chambers that did not receive FeCl₂ showed no sign of such growth. Furthermore, after 4 to 5 days the chambers fed with FeCl₂ contained 35 to 75% more protein than chambers not supplemented with FeCl₂. Leptothrix ochracea and, to a lesser extent, Gallionella spp. were responsible for the filamentous growth, and the sheaths and stalks, respectively, of these two organisms harbored large numbers of Fe-encrusted, nonappendaged unicellular bacteria. In chambers where particulate growth predominated, the unicellular bacteria alone appeared to be the primary agents of iron oxidation. These results provide the first clear evidence that the “iron bacteria” commonly found associated with neutral-pH iron seeps are responsible for most of the iron oxidation and that the presence of ferrous iron appears to stimulate the growth of these organisms.     

Investigation of an Iron-Oxidizing Microbial Mat Community Located near Aarhus, Denmark: Field Studies

We investigated the microbial community that developed at an iron seep where anoxic groundwater containing up to 250 μM Fe²⁺ flowed out of a rock wall and dense, mat-like aggregations of ferric hydroxides formed at the oxic-anoxic interface. In situ analysis with oxygen microelectrodes revealed that the oxygen concentrations in the mat were rarely more than 50% of air saturation and that the oxygen penetration depth was quite variable, ranging from <0.05 cm to several centimeters. The bulk pH of the mat ranged from 7.1 to 7.6. There appeared to be a correlation between the flow rates at different subsites of the mat and the morphotypes of the microorganisms and Fe oxides that developed. In subsites with low flow rates (<2 ml/s), the iron-encrusted sheaths of Leptothrix ochracea predominated. Miniature cores revealed that the top few millimeters of the mat consisted primarily of L. ochracea sheaths, only about 7% of which contained filaments of cells. Deeper in the mat, large particulate oxides developed, which were often heavily colonized by unicellular bacteria that were made visible by staining with acridine orange. Direct cell counts revealed that the number of bacteria increased from approximately 10⁸ to 10⁹ cells per cm³ and the total iron concentration increased from approximately 0.5 to 3 mmol/cm³ with depth in the mat. Primarily because of the growth of L. ochracea, the mat could accrete at rates of up to 3.1 mm/day at these subsites. The iron-encrusted stalks of Gallionella spp. prevailed in localized zones of the same low-flow-rate subsites, usually close to where the source water emanated from the wall. These latter zones had the lowest O₂ concentrations (<10% of the ambient concentration), confirming the microaerobic nature of Gallionella spp. In subsites with high flow rates (>6 ml/s) particulate Fe oxides were dominant; direct counts revealed that up to 10⁹ cells of primarily unicellular bacteria per cm³ were associated with these particulate oxides. These zones exhibited little vertical stratification in either the number of cells or iron concentration. Finally, mat samples incubated anaerobically in the presence of acetate or succinate exhibited significant potential for iron reduction, suggesting the possibility that a localized iron cycle could occur within the mat community.     

濒危植物小勾儿茶伴生群落特征研究

从植物生活型、群落垂直结构、物种多样性以及群落稳定性4个方面研究小勾儿茶伴生群落特征,分析小勾儿茶在该生境幸存的原因。生活型谱反映出生境温热高湿且四季分明的亚热带气候特点;小勾儿茶处于群落顶层,能够获得充足的阳光;群落结构稳定、物种丰富。小勾儿茶的数量已极为稀少,应采取调查、保护和扩繁3种主要措施扩大其种群数量,即：(1)加大力度在相似的生境中寻找小勾儿茶;(2)对其生境加大保护力度;(3)开展种子生理方面的研究,探索有效的发芽途径,同时用组培的方法繁殖幼苗。     

Studies on the Population and Community Characteristics in Platycladus orientalis Forest

The population and community characteristics in the Platycladus orientalis forest on Qianfo Mountain in Jinan are studied. The specific composition, spatial pattern, biological spectrum and main species dispersions are reported. It is found that all the main species dispersions are aggregated. The diversity of Shannon-Wiener and Simpson indexes are markedly not correlated with the habitat factors. The patch indexes and niche breadths of the main species have been analysed on such axes as light, soil water and soil organic matter. The value of niche overlap between every two species is high on soil resource axis.     

井冈山云锦杜鹃群落特征研究

以井冈山云锦杜鹃群落10个样地调查资料为基础,对该群落的物种组成、区系成分、群落结构和物种多样性进行研究。结果表明：该群落有维管植物44科67属83种,其中蕨类植物有6科6属6种,裸子植物4科4属5种,被子植物34科57属72种;区系分析显示,该群落植物区系地理成分复杂,热带性成分和温带成分均占较大比例;群落为复层异龄结构,云锦杜鹃、交让木和猴头杜鹃是组成该群落的建群种;物种多样性分析显示,群落Simpson指数和Pielou指数较高,Shannon-Wiener指数和物种丰富度指数较低,物种多样性指数在样地间有一定差异,在群落不同层次未表现出一致的变化规律。     

浙江仙居俞坑森林群落特征研究

浙江省仙居县俞坑境内由于地形复杂 ,水热条件优越 ,加上以前交通不便 ,限制了人类的频繁活动 ,使原有的植物种类得以保存和发展。这是括苍山系仅存的一片次生湿润常绿阔叶林 ,属中亚热带低海拔地区典型的地带性植被。此地于 1991年建立了县级自然保护区 ,目前对该群落仅在演替方面作过研究[1] 。本文主要对该群落的特征进行研究 ,为这一类型的植被研究和资源保护提供资料。1　自然概况俞坑位于浙江省仙居县境内 ,距括苍山主峰米筛浪约 4 0ｋｍ ,为括苍山尾部。地理位置为 2 8°0′5″Ｎ、12 0°0′5″Ｅ ,面积约 3ｋｍ2 [2 ] ,海拔高度在 4…