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1.
豫东平原聚落景观格局变化   总被引:4,自引:1,他引:3  
杨慧敏  娄帆  李小建  白燕飞 《生态学报》2017,37(16):5313-5323
中国的快速城镇化必然导致聚落景观格局的变化,但目前相关研究对平原地区关注相对较少。文中选取豫东平原地区的开封、商丘、周口市,运用GIS空间分析方法和ENVI遥感影像处理技术,对该地区1972、2015年市域中观尺度上的聚落规模、聚落景观空间变化特征进行分析。结果显示:(1)在聚落发展过程中,1972—2015年聚落斑块数量有所减少,聚落规模逐渐扩张,市域内最大聚落斑块扩张相对更为明显;对聚落斑块扩张强度的分析发现,城市市辖区及周边乡镇聚落扩张强度相对较高。(2)地区内聚落斑块空间分布表现出聚集分布特征,但该时期聚集程度有所减弱;两个年份聚落核密度分布格局大致相似,局部地区存在多核扩散现象,市域尺度上的核密度分布存在地区差异。(3)对斑块形状指数的分析发现,研究区狭长或曲折聚落斑块在空间上分散布局,整体上区域内聚落形状趋于规则。(4)随着距河流、道路距离的增加,聚落斑块总面积和数量有所减少,且道路对聚落分布仅在一定范围内存在较大影响,距中心城市0—6km范围内聚落受中心城区发展辐射影响较大。本文的分析可为平原地区聚落景观的优化布局和聚落用地的集约化发展提供一定的参考。  相似文献   

2.
The paper presents a study of settlement processes in western Nepal. It emphasizes the linkages between settlement history, cultural ecology, and political economy as these relate to resources, marginality, and territory. Regional settlement trends are examined in accordance with land occupancy and tenure arrangements. Village settlement strategies are analyzed within a micro-processual framework that incorporates political economic perspectives on village land use and resource distributions. The past, present, and future roles of settlement in the human adaptation process of west Nepal's mountain populations is critically examined in the contexts of historical land policies and current rural political and environmental systems.  相似文献   

3.
乡村生态学概论   总被引:10,自引:0,他引:10  
城市生态学已逐渐发展成一门受众人肯定的生态学分支学科,但乡村生态学未引起广泛重视。本文定义乡村生态学为研究村落形态、结构、行为及其与环境本底统一体客观存在的生态学分支科学。村落是以一定年龄结构、一定数量人口或人群为基本特征,以户为组成单位,以土地为经营对象,以相应的生物(牲畜和作物)为主要价值资源的人类聚居的空间单元。村落除具空间和生命涵义外,还直接联系地理位置、地形地势、气候、土壤和植被等景观要素与资源参数;同时,它还与历史传统、社会习俗等多方面复杂因素有关。乡村生态学的意义在于揭示村落与所有这些相关因素的关系,并用以指导乡村建设。  相似文献   

4.
城市生态学已逐渐发展成一门受众人肯定的生态学分支学科,但乡村生态学未引起广泛重视。本文定义乡村生态学为研究村落形态、结构、行为及其与环境本底统一体客观存在的生态学分支科学。村落是以一定年龄结构、一定数量人口或人群为基本特征,以户为组成单位,以土地为经营对象,以相应的生物(牲畜和作物)为主要价值资源的人类聚居的空间单元。村落除具空间和生命涵义外,还直接联系地理位置、地形地势、气候、土壤和植被等景观要素与资源参数;同时,它还与历史传统、社会习俗等多方面复杂因素有关。乡村生态学的意义在于揭示村落与所有这些相关因素的关系,并用以指导乡村建设。  相似文献   

5.
1. The hydraulic and geomorphic characteristics of stream patches are often associated with distinctive assemblages or densities of stream invertebrates, and it is routinely presumed that these patterns reflect primarily species‐specific habitat requirements. An alternative hypothesis is that such patterns may be influenced by constraints on movement, such as the results of departure and settlement processes. We describe a manipulative experiment that examined how the hydraulic environments created by topographic bedforms influenced the drift behaviour and potential settlement sites for two species of mayfly (Baetis rhodani and Ecdyonurus torrentis). These species are common in the drift and often co‐occur in streams, but differ in their small‐scale distribution patterns, body shape and movement behaviour. 2. Flume experiments were carried out to determine how the hydraulic environments conditioned by a step bedform influence the behaviour of mayflies in the drift (swimming, posturing, tumbling), and the consequences of those behaviours (drift distance and time), compared to drift over a plane bed. The ramped step in the flume mimicked step bedforms that are common in coarse‐grained, high‐gradient streams. In contrast to the plane bed, a zone of recirculating flow was created downstream of the step, above which flow was faster and more turbulent. Uniform flows are used in most flume studies of drift; our approach is novel in recreating a complex hydraulic environment characteristic of stream channels. 3. Both species had some behavioural control over drift, and drift distances and times were shorter for live larvae than for dead larvae over the plane bed. The step had no impact on drift time or distance for live Baetis, but dead larvae were trapped in the flow separation eddy and drift time increased accordingly. Some Ecdyonurus also became trapped in the eddy, but live larvae drifted farther than dead larvae, and farther over the step than the plane bed. 4. Whilst in the drift, larvae altered their behaviour according to the ambient hydraulic environment, but in a species‐specific manner. Over the plane bed, Baetis had occasional swimming bursts, but primarily postured (maintained a stable body orientation), whereas Ecdyonurus spent roughly equal time posturing and swimming. In the more turbulent flows generated by the step, Baetis spent proportionately more time swimming, whereas Ecdyonurus spent more time posturing and often tumbling as body orientation became unstable. 5. In a high‐gradient stream, Baetis was more abundant close to steps than in plane bed patches with less complex flow, whereas the opposite pattern held for Ecdyonurus. Thus, the small‐scale distribution patterns of these species within streams correspond to their drift behaviours and ability to access various hydraulic patch types in our flume. These results are consistent with the hypothesis that constraints on movement and settlement may be important driver of distribution patterns within streams.  相似文献   

6.
史利莎  严力蛟  黄璐  许智钇 《生态学报》2011,31(21):6305-6316
中国传统乡土聚落作为多功能景观,其保护研究是我国生态及文化保护工作的重要组成部分,是可持续科学和跨学科研究的典型载体。从文化和生态两条研究路线出发,同时运用中国传统风水生态理念和现代景观格局理论对甘肃省迭部县扎尕那村藏族乡土聚落的景观立体结构、生态要素构成进行不同角度的解构,探析理想景观模式蕴含的生态合理性及文化与环境在聚落发展中的相互关系。风水模式分析表明扎尕那聚落立体结构为"盆地-豁口-走廊"的壶天模式,符合中国人心目中理想的"山-林-屋-水-林"景观模式,其空间要素组成在水平和垂直方向上均表现出以人类活动为中心的圈层结构。综合自然地理环境要素契合"藏风得水"的理想风水格局,整体形成以寺庙为核心的组团式聚居格局,各个独立自然村落具有相似的界面特征。景观格局指数分析表明扎尕那聚落景观以有林地和裸岩为基质,景观异质性和景观连接度都较高。人工斑块比例很低,聚落属于极稀疏区,人类活动对于自然环境的干扰较小。多重文化和自然环境的综合作用是扎尕那聚落格局演化的主要驱动因子。本研究为扎尕那聚落的保护和发展模式的制定奠定了理论基础,对于文化与环境相互关系的研究及中国多功能景观研究模式的探索具有一定的理论意义和应用价值。  相似文献   

7.
《Plains anthropologist》2013,58(42):310-338
Abstract

An examination of this site on the west bank of the Missouri River in north-central South Dakota has revealed an unfortified settlement of approximately 30 earthlodges. The settlement pattern and artifact inventory indicate that the Fox Island site is an Extended Coalescent village that appears to be a descendant of the complex defined at Mols, tad Village.  相似文献   

8.
Blood pressure variation was investigated among populations inhabiting islands and peninsula of Middle Dalmatia, Croatia. The number of previous anthropological studies pointed to isolation and different genetic population structure in this environmentally fairly homogeneous area. Variation in blood pressure (systolic and diastolic) among the populations of the islands of Brac, Hvar, Korcula, and the Peljesac peninsula was assessed at three levels involving village populations, regional (western and eastern) populations and the entire island populations. The blood pressure data were collected from 3834 adult individuals inhabiting 37 rural communities and were adjusted for age and body mass index. Variation in blood pressure levels existed among regions and villages. Due to the history of differential settlement, small village sizes and high levels of reproductive isolation, the observed blood pressure variation could be attributed to founder effect, genetic drift and inbreeding. The involvement of genetic factors was tested by relating blood pressure variation among villages to degree of isolation among them. Blood pressure means and proportions of hypertensives increased with endogamy levels in males. In females, this effect could not be observed. However, in both sexes the highest proportions of hypertensives (more than 40%) were found in villages that are most reproductively closed (endogamy greater than 80%). These populations are considered particularly promising for further genetic epidemiological research.  相似文献   

9.
ABSTRACT

In remote villages of the Eastern Highlands of Papua New Guinea, where official village courts and other state institutions are absent, local leaders routinely hold unofficial village courts to maintain law and order. They base their decisions on local perceptions of order and justice, all the while emulating elements of state justice and constantly referring to the state as the source of their legitimacy. As these unofficial judicial institutions historically emerged as a convergence of local patterns of leadership with colonial concepts of order, they neither form a completely new nor completely autochthonous method of conflict settlement, but are an example of para-statehood, in which local leaders take on state functions in the absence of the state.  相似文献   

10.
《Plains anthropologist》2013,58(95):37-56
Abstract

In 1976 Alfred E. Johnson proposed a subsistencesettlement model for Kansas City Hopewell. The model consisted of a subsistence territory encompassirig a drainage upon which a large permanent village settlement was located near its mouth with a series of smaller specialized ancillary sites located up from the village. Limited corn and squash horticulture would be present in the latter half of the occupation too. A test of such a model would be actual limited activity sites. The Yeo site, a late kansas City Hopewell site, is a hickory nut/marsh elder seed collection/storage station. It is exactly the type of site necessary to substantiate such a model. Also, such a test implies the testing of the notion that there are “specialized, limited activity sites,” sites which are important to some of the suppositions of the New Archaeology. Additionally, the presence of the combination of hickory/cultivated marsh elder (Iva annua var. macrocarpa) utilization within the context of an upland oak-history forest may be interpreted as supporting Asch and Asch’s (1978) model of marsh elder domestication.  相似文献   

11.
P. Pyšek 《Plant Ecology》1993,106(1):89-100
Published data on the number of plant species and/or communities were gathered for 77 European cities and 85 villages. The relationships between the floristic and vegetation diversity and some environmental variables were analysed. Species number in cities showed log linear increase with city size (expressed as the population size or city area). A linear increase in the species number with size was found in the village flora. The richness of both city and village flora was not significantly related to any climatic variable. On the contrary, the number of communities in both villages and cities was correlated not only with settlement size but also with altitude and mean annual temperature. The diversity of village vegetation was closely related to the climax type of the respective region. The features of human settlements that make it possible to consider them as landscape islands are discussed.  相似文献   

12.
The unlikely high frequency of G6PD deficiency which we found in a mountain village (San Giovanni in Fiore: province of Cosenza — Calabria, Southern Italy), with respect to the mean frequency of the other mountain villages in the same province, led us to carry out some investigations on the population of this village to understand this difference. The historical analysis, together with the social-demographic, endogamic and isonymyc study revealed the isolation of this village; while, the analysis of the allele frequencies of AK, ADA, 6PGD, PGM1, ABO and Rh markers revealed no significant differences if compared to the rest of the province. But the AK*5 variant which we found in ten unrelated subjects with a frequency of 0.0104, allows us to hypothesise together with the high G6PD frequency a random genetic drift effect on this village.  相似文献   

13.
Dina M. Fonseca 《Oecologia》1999,121(2):212-223
I propose proximal mechanisms that help explain, unify, and expand the predictions of widely accepted empirical models of settlement in streams. I separated the process that leads to settlement of a drifting particle into three stages: (1) initial contact with a substrate, (2) attachment, and (3) settlement sensu stricto. I used physical principles (height above the bed, sinking rate, current speed profile) to predict time until contact (stage 1). I compared these predictions with empirical measurements of settlement of individual black fly larvae (Simulium vittatum) in a laboratory flume. I developed models from empirical data for stages 2 and 3. Each of these models is individual-based and predicts the fate of a single individual. To obtain a population level prediction, models for the three stages were combined and used to simulate the settlement of a group of black fly larvae. The predictions of this simulation were qualitatively similar to population level data from the literature particularly after the incorporation of channel-wide spatial heterogeneity in current speed. The effect of flow heterogeneity on the model agrees with previous work on the lateral transport of stream invertebrates during drift events showing that many organisms settle preferentially in slower areas. By using proximal principles, the approach used in this study brings into focus basic parameters and processes that influence settlement at the scale of the organisms. It also provides a null hypothesis against which to study the effect of local flow heterogeneity on the settlement of stream invertebrates and the capacity of organisms to actively influence settlement. Water currents in streams and rivers commonly transport large numbers of organisms. Consequently, hydrodynamic factors that favor or hamper the settlement of these organisms can potentially influence distributions and abundance. Moreover, if settlement probabilities vary with flow characteristics, this can in turn influence foraging strategies that rely on fluid-mediated dispersal. Received: 9 January 1999 / Accepted: 8 June 1999  相似文献   

14.
After more than twenty-five years on the legal landscape of Papua New Guinea, 'customary law' is ripe for reassessment, particularly as it appears to be an ideal mechanism with which the Papua New Guinean state can meet some of its obligations to a burgeoning body of international law. This article addresses the need to understand customary law in the context of its varying usage across different legal domains in an archetypally pluralistic state. In contrast to older approaches focusing on the problematic interface between an exogenous legal system and indigenous methods of dispute settlement, my concern is with the ways in which these distinct legal forms have fared in each other's company since independence in 1975. Case-studies from a village court and an urban national court demonstrate that village court magistrates and high court judges alike use custom and law as strategic sources of authority. While village courts take custom for granted and therefore must 'discover' law, high courts take law for granted and must 'discover' custom. These processes indicate that, rather than being hybridized as 'customary law', the distinctiveness of custom and law are often maintained in order for one to appear as a resource upon which the other can draw.  相似文献   

15.
In this study, we focused on the drivers of micro- and mesohabitat variation of drift in a small trout stream with the goal of understanding the factors that influence the abundance of prey for drift-feeding fish. We hypothesized that there would be a positive relationship between velocity and drift abundance (biomass concentration, mg/m3) across multiple spatial scales, and compared seasonal variation in abundance of drifting terrestrial and aquatic invertebrates in habitats that represent the fundamental constituents of stream channels (pools, glides, runs, and riffles). We also examined how drift abundance varied spatially within the water column. We found no relationship between drift concentration and velocity at the microhabitat scale within individual pools or riffles, suggesting that turbulence and short distances between high- and low-velocity microhabitats minimize changes in drift concentration through settlement in slower velocity microhabitats. There were also minimal differences in summer low-flow drift abundance at the mesohabitat scale, although drift concentration was highest in riffle habitats. Similarly, there was no differentiation of drifting invertebrate community structure among summer samples collected from pools, glides, runs, and riffles. Drift concentration was significantly higher in winter than in summer, and variation in drift within individual mesohabitat types (e.g., pools or riffles) was lower during winter high flows. As expected, summer surface samples also had a significantly higher proportion of terrestrial invertebrates and higher overall biomass than samples collected from within the water column. Our results suggest that turbulence and the short length of different habitat types in small streams tend to homogenize drift concentration, and that spatial variation in drift concentrations may be affected as much by fish predation as by entrainment rates from the benthos. Handling editor: Robert Bailey  相似文献   

16.
Witness tree data from the southeastern United States (lat 33°30' N, long 86°30' W) were analyzed using catchment and distance analysis to quantify the effects of Native American settlement on the composition of forest trees. Thirty Creek Indian villages comprising 18 settlement catchments were included in the sample, which is the largest Native American–forest interaction study using witness trees to date. Lower frequencies of Pinus spp. were observed within village catchments of the Coastal Plain and Ridge and Valley. Elevated frequencies of early succession species were observed surrounding 2 km village catchments. Distance analysis at two relatively isolated towns showed that Pinus increases in frequency beyond 2000 m from villages while Carya had the opposite result. Field and fruit species were more frequent within 6000 m of villages and then dropped off in frequency. Fire-sensitive tree species appear to be in a spatially cyclical pattern.  相似文献   

17.
Human leucocyte antigen (HLA) loci have a complex evolution where both stochastic (e.g. genetic drift) and deterministic (natural selection) forces are involved. Owing to their extraordinary level of polymorphism, HLA genes are useful markers for reconstructing human settlement history. However, HLA variation often deviates significantly from neutral expectations towards an excess of genetic diversity. Because HLA molecules play a crucial role in immunity, this observation is generally explained by pathogen-driven-balancing selection (PDBS). In this study, we investigate the PDBS model by analysing HLA allelic diversity on a large database of 535 populations in relation to pathogen richness. Our results confirm that geographical distances are excellent predictors of HLA genetic differentiation worldwide. We also find a significant positive correlation between genetic diversity and pathogen richness at two HLA class I loci (HLA-A and -B), as predicted by PDBS, and a significant negative correlation at one HLA class II locus (HLA-DQB1). Although these effects are weak, as shown by a loss of significance when populations submitted to rapid genetic drift are removed from the analysis, the inverse relationship between genetic diversity and pathogen richness at different loci indicates that HLA genes have adopted distinct evolutionary strategies to provide immune protection in pathogen-rich environments.  相似文献   

18.
Subsistence hunting among the Waimiri Atroari Indians in central Amazonia, Brazil, was studied from September 1993 to October 1994 to assess the current levels of resource exploitation. Hunting effort, harvesting yields and species composition of the hunt were recorded daily in five villages varying in number of people, location and age of the settlement. The Waimiri Atroari harvested a total of 3004 individuals of 41 species in one year. Lowland tapir (Tapirus terrestris), white-lipped peccary (Tayassu pecari), collared peccary (T. tajacu) and spider monkey (Ateles paniscus) represented 87% of the total yearly game weight. Sex ratios of spider monkeys killed were heavily biased towards females indicating a stronger hunting pressure on those individuals. Harvesting yields was proportional to hunting efforts indicating no evident game depletion in the study period. However, capture per unit of effort was significantly different among villages. Differences in total game mass harvested may be explained by local resource depletion associated with age and size of the settlement. However, this relationship is confounded by the capacity of some villages to exploit distant hunting sites. Data obtained in one village showed that harvest rates were higher in hunting sites located far from settlement indicating game depletion in hunting sites surrounding the village.  相似文献   

19.
Abstract. Settlement timing and differential settlement for the larval stage of the green sea urchin, Strongylocentrotus droebachiensis , in the southern Gulf of Maine was studied during the summer of 1996. Settlement densities on astroturf panels were highest in June and early July (13 to 37 m −2 d−1), and peaked in mid-June (199 m−2 d−1). Settlement was low to nonexistent from mid-July through August (0 to 2 m−2 d−1). During the peak in settlement, no selection for substrate type was observed. In the remainder of the settlement period, differential settlement occurred, with a preference for substrate covered with live coralline algae. Test diameter of newly settled urchins varied among the substrates, with urchins settling on live coralline algae having the largest test diameter (0.43 ± 0.01 mm). There were no differences in test diameter among the different weeks in which sampling was done. Sustained onshore winds occurred only during peak settlement, suggesting that wind drift currents may concentrate larvae and influence patterns of larval settlement.  相似文献   

20.
The village of Pegrema in Karelia may be regarded as a Stone Age innovation centre in the large Lake Onega area. Two pollen and plant macrofossil diagrams are presented which represent the first contribution to the study of human impact in the area using anthropogenic pollen indicators. A continuous but sporadic human presence from the Mesolithic onwards is demonstrated. While there is no archaeological evidence relating to the period 4200–3000 B.P., the pollen data suggest continuous, though rather sparse human presence. The data do not support any natural catastrophes in Pegrema as has been suggested elsewhere. Cerealia pollen is recorded earlier than expected (c. 5000 B.P.=. In the Bronce Age and Iron Age, the settlement of the Zaonezhye peninsula is reflected by a slight increase in herb pollen representation, sporadic Cerealia pollen and several periods of regression in Picea. The long introductory period of agriculture to the area, as well as the similarities and discrepancies between different sources of evidence (palaeoecological, archaeological and historical) are discussed at some length. The start of land clearance for permanent cultivation in the profile Pegrema S was dated to the late 13th century. The beginning of more intensive field cultivation in the 15th century is clearly seen in the pollen succession at both localities. The fluctuation in anthropogenic indicators can be related to population density based on historical data. The village of Pegrema was depopulated in 1956 which is reflected in a distinct decline in settlement indicators. Received February 17 / Accepted May 19, 2000  相似文献   

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