北京市郊区可持续景观生态规划及 优化生态生产范式研究——以昌平区为例

北京市郊区可持续景观生态规划及优化生态生产范式研究是指要遵循区域自然地理要素的分异规律，以土地利用现状格局为基础，以景观生态学原理和可持续发展准则为理论指导，以景观空间分析为具体研究内容来揭示区域土地利用类型结构、功能的异质性和有序性，以期提出优化的土地利用格局。本论文主要通过大量数据、图件的收集、野外考察与调查，文献查阅与数据处理、分析，得出以下主要结论： 一、理论方面 基于景观生态学理论——景观要素，空间结构与生态学过程，景观动态，异质性，等级结构，连接度以及景观的时空性等，以北京地区为例阐述了景观生态学理论如何合理地整合于生态建设与保育之中，并重点阐释了北京生态建设与保育“小三圈”格局的结构与功能，该系统包括山区外圈层、郊区平原中圈层和城区内圈层，其目标要实现：(1)山区发挥以水源涵养、水土保持防护为主的生态功能;(2)郊区创建农田、林地、草地异质性的人工稀树草原景观，形成带、网、片、点相结合的绿网系统;(3)城区以自身绿化和美化为主。同时，本研究针对我国的区域可持续发展进一步提出更加有效的建设性意见：(1)开展区域生态适宜性评价;(2)区域水平的土地利用格局、动态以及预测性研究;(3)进行区域可持续景观生态规划，建立区域优化生态生产范式，最终实现可持续发展目标。 二、研究方法方面 利用空间自相关指数，并结合“城-郊-乡”梯度分析法研究景观格局对尺度（包括粒度、幅度、方向）变化的响应。得出以下主要结论： 1、景观格局对于尺度变化有着不同的响应，随着空间粒度的增加，空间自相关均呈下降趋势;随着幅度的增加，空间自相关基本不变;人类干扰较多的景观几乎不受“划区效应”的影响;不同的数据类型，同一数据类型的不同景观对于尺度的变化均有着不同的响应。 2、沿“城-郊-乡”样带，空间自相关呈阶梯状增加趋势。景观空间自相关大小顺序：林牧景观>林果景观>农田景观>都市景观>都市化景观，人为干扰较多的景观具有较低的空间自相关，但对尺度的变化表现出较强的敏感性。 三、实例研究 北京市郊区可持续景观生态规划及优化生态生产范式研究是以昌平区为例，从昌平区经济与产业结构现状分析出发、以昌平区土壤理化性状分析为背景，以景观格局现状、动态，以及土地利用内部转移格局与过程、驱动因素分析为主要内容，并且重点探讨了昌平区城镇化的过程特征及空间特征，得出以下主要结论： 1、昌平区GDP配比方式，以及昌平区农村GDP结构模式均为“三二一”。昌平区在北京市农业中的地位，以及农业在昌平区GDP中所处地位均弱化。截止2001年，昌平区农业产值中，牧业>种植业>渔业>林业，牧业居于首位，占到46.70%，而传统种植业也正以小汤山为龙头向现代化、高科技、高效化的“六种农业”转化。总体讲，农业的粮食生产功能在昌平区已不再是一个重要功能，传统种植业正逐步地让位于畜牧业（人工牧草）、林业（疏林、苗圃），突出体现了具有良好生态学效益的牧草、林果在未来大农业发展中的战略地位。 2、昌平土壤肥力状况良好，景观分区与土壤理化性质是吻合的。基于土壤理化基质，昌平区应形成林、灌、草为主的山区景观，园林式城镇、林、果、灌相结合的山前倾斜平原景观，以及农、林、草配置的生态农业景观和花卉、种苗、绿化带相辉映的绿色生态住宅景观。 3、从1989~2001年期间，研究区内土地利用景观经历了很大的变化。土地利用景观的量变主要体现在城镇用地的迅速扩张和耕地的锐减，而土地利用类型的变化则体现在水田、传统菜地的逐渐消失，以及2001年后人工牧草的大面积推广种植。景观格局在不同景观分区的差异也得以论证，中北部山麓平原卫星城镇、旅游林果区（III）具有最高的多样性和最低的优势度、聚集度，中南部平原高科技、都市生态农业区（II）的多样性最低，而优势度、聚集度最高，对于南部平原都市边缘、城镇住宅区（I）各指标则介于III和II区之间。 4、从1989~2001年期间，土地利用的内部转移主要体现在耕地向城镇用地的大面积转移，其次，传统菜地转向城镇用地和其他种植耕地，而人工牧草是由部分耕地转移而来的。城镇化、水资源短缺和农业政策是主要驱动因素。土地利用的内部转移具有明显的区域差异，中北部山麓平原卫星城、旅游林果区体现出卫星城镇的发展，南部平原都市边缘住宅区则反映出北京都市边缘的向外扩张，而中南部平原高科技都市农业区则正向现代化的、高科技都市农业示范区发展。 5、昌平区三种主要的城镇化模式，即都市边缘带状城镇扩展模式、交通主轴线状城镇扩展模式和卫星城面状城镇扩展模式。研究表明，昌平区的城镇化主要集中在1989~1996年期间。 基于昌平区的产业与经济结构现状，土壤养分状况，景观结构现状、动态，土地利用转移方向，并且结合昌平区自然地理分异规律，社会经济因素对昌平区进行了可持续景观规划，昌平区应遵循的四个景观分区为：北部中低山生态保护、生态旅游区;中北部山麓平原卫星城镇、旅游林果区;中南部平原高科技、都市生态农业区;南部平原都市边缘、城镇住宅区。 最后作为总结、归纳，我们提出昌平区优化生态生产范式，昌平区的发展应定位于（1）生态环境保护与水源涵养的生态功能;（2）教育、示范、创新功能;（3）生活功能，并且遵循自然地域分异规律原则、因地制宜原则、生态主导性原则、统筹兼顾原则，大力发展昌平区经济的优势产业，即畜牧业、林果业和旅游业，突出肉羊、苹果、牧草和林木种苗等四个具有昌平特色的主导产业。 景观生态学;景观空间格局;可持续景观生态规划;土地利用变化;优化生态生产范式;北京昌平区

松嫩平原农牧交错区优化生态-生产范式——以长岭县为例

松嫩平原农牧交错区位于松嫩平原的西部，中国北方农牧交错带的最东端;具有独特的地质环境特点，环境问题突出，是我国生态脆弱地区之一，及世界三大苏打盐碱土集中分布区之一。近年来，由于人为的不合理利用和开垦、以及粗放的生产模式，使该地区生态系统严重受损，土地沙漠化、水土流失、盐碱化、土地生产力下降等生态环境问题日益突出。因此，建立一个适合该地区生态环境条件、社会经济发展状况的优化生态-生产范式是必要而紧迫的。 本论文以松嫩平原农牧交错区为研究对象，以其典型地段为切入点，通过大量数据的收集、文献资料的查阅、野外考察与测定、室内分析处理等，得出了以下主要结论： 一、生态-地理环境背景分析 松嫩平原农牧交错区是多种生态-地理环境危害并存的区域，其中包括盐碱化、沙漠化、气候灾害、水资源短缺等等。当前，沙化土地和盐碱化土地的面积已占该地区土地总面积的34.27 %，并且呈逐年递增的趋势。松嫩平原农牧交错区气候灾害频发，主要是旱灾、水灾、风灾。此外，水资源短缺以及水质问题，同样影响着农业生产及社会经济发展。造成松嫩平原农牧交错区多种生态-地质环境危害并存的主要影响机制是：该地区自身的地质-地理环境特点、气候因素和人类活动的综合效应，并且人类活动日益成为主要驱动因子。 二、实例研究 松嫩平原农牧交错区优化生态-生产范式研究是以长岭县为例，通过对长岭县景观格局变化分析、土壤格局分布、农牧业生产特点、以及农业可持续性评价等，得出以下结论： 1、对研究区内土地利用格局分析表明：1980 ~ 2000年，在土地利用类型没有发生变化的基础上，表现为各土地利用类型面积上的增减;草地、林地大面积地向农田转移，农田面积明显增加;大规模地开垦农田，已经导致了景观的优势度增加，破碎度增加，多样性下降，这最终将使整个景观趋于更加不稳定。 2、长岭县土壤总体水平较差，障碍性土壤占长岭县总土地面积的55.38 %。从土地利用变化对不同地势条件下土壤理化性状影响分析，结果表明：（1）地势相对高的平台地，土壤肥力较高，且开垦对土壤理化性质的影响相对较小，更适合农业开发;（2）低地原生植被为草甸草原，其养分状况也比较好，但其地势较低，易发生水渍和盐碱化;（3）坡地是当地土壤养分最为贫瘠地区，也是风沙土较集中分布的区域，对其开垦会增大土壤的风蚀和水蚀，使土壤养分状况严重下降。 3、对研究区牧草资源分布格局、牧草资源承载力和利用现状等进行分析，结果表明：放牧系统提供的牧草资源已不能满足当地畜牧业对牧草资源的需求。草地提供的牧草资源仅能满足总牧草需求的16.6 %，放牧系统提供的牧草仅占总牧草需求的47.3 %;玉米秸秆转化为牧草资源的潜力巨大，经估算，占总牧草资源的78.3 %，其承载力为总牧草需求的2.4倍。当前，农牧交错区牧草资源的粗蛋白含量普遍偏低，不能完全满足动物生产的需要，制约了当地畜牧业发展。根据当地畜牧业现状、牧草资源潜力，我们提出：应在合理利用当地牧草资源的基础上，有计划地建立高产优质、富含粗蛋白的人工牧草基地，实现畜牧业可持续发展与生态保护的协调统一。 4、长岭县是以第一产业为主，即农业生产为主要经济来源。对农业生产结构的分析表明：农牧业生产占总农业产值的90 %以上，并以种植业为主，种植业一直占总农业产值60 %以上。受当地气候条件、土壤格局分布的限制，单一粮食生产、粗放的生产模式以及对天然草地资源的过分依赖，最终导致该地区农牧业发展缓慢，经济条件落后。 5、在上述分析的基础上，作者提出了长岭县优化生态-生产范式，即以高效农业生产、生活圈，水土保持和自然生态保育圈、牧草生产基地及生态功能保护圈的三圈等级系统。以此为依据，对土地利用格局进行调整，通过粮、草、经多元农业结构的建设，在合理利用与保护草地的基础上，使长岭县畜牧业走向产业化的发展模式。

Zooplankton biomass along the west coast of India and its effect on the fishery

The coastal zone along the west coast of India is very productive with a mean secondary production rate of 5.89 mg C/m super(3)/day. Statewise, maximum zooplankton standing stock was observed off Maharashtra. The existing yield of fishery from the surveyed region has been compared with the estimated sustainable fishery potential.

Record catch of rock perch, Epinephelus fasciatus by bottom trawling off Ratnagiri

A productive fishing ground for rock perch (Epinephelus fasciatus) was located off Ratnagiri between 17 degree 00' to 17 degree 10' N latitude and 72 degree 20' to 72 degree 30' E longitude, around a depth of 96m during November, 1983. An average catch of 2 ton/hr. was recorded. Length frequency studies of E. fasciatus indicate the probability of a nursery ground consisting of three brood stocks. Hydrographic studies of the ground revealed that the bottom water was oxygen deficient below a strong thermocline extending from 15-75 m depth with the recorded bottom temperature amounting to 20.5 degree C.

Impact of the exotic fish, Oreochromis mossambicus, on the indigenous fishery of Powai Lake, Bombay

Fishes impart the most profound influence on the floral-faunistic characteristics of an aquatic ecosystem. Oreochromis mossambicus, an exotic fish accidentally introduced in the Powai lake, India, caused considerable changes in the growth pattern of Indian major carps, ultimately reducing the productive potential of the lake from 33.0 to 11.9 kh/ha. Powai lake is used exclusively for angling for sport. The angling pressure based on the "creel census" from 1955 to 1976 gives a clear picture of the trends in the fishery therein. A considerable decline, ranging from 171 to 400% in the average weight of Indian major carps was recorded.

Soil quality of Bhilwara District (Rajasthan) in relation to pisciculture

The present paper deals with the physico-chemical data of 13 rainfed and drainable dry bundhs of Bhilwara District (India). All the dry bundhs studied showed a slightly alkaline pH ranging from 7.5 to 8.5. Electrical conductivity ranged from 2 to 8 millimhos/cm. Organic carbon in sediment fluctuated from 0.30 to 0.75%. Nitrogen, phosphate and potassium levels were fairly good, at 30 to 50 and 24 to 36 mg/100 g of soil respectively. Based on these data it was inferred that these dry bundhs were highly productive and suitable for freshwater fish culture.

Biochemical composition of zooplankton from the northern Arabian Sea

Zooplankton standing crop and proximate principals were estimated for 8 coastal and 13 oceanic stations of the northern Arabian Sea during March 1991. Biomass did not show any significant difference (p < 0.05) between coastal and oceanic waters. Protein was the principal biochemical component among proximate principals with an average value of 29.6% in coastal and 34.2% in the oceanic zone, suggesting that protein form a major metabolic reserve. Other components such as lipids and carbohydrate seem to be low in tropical zooplankton. The organic carbon and caloric density did not show significant correlation. Average caloric density was 2.5 k.cal super(-1). The average standing stock was 9.25 mg m super(-3) and 5.90 mg m super(-3) for coastal and oceanic water, respectively. Coastal region is more productive than oceanic region in terms of standing crop, as expected.

The 1958 pearl oyster fishery, Gulf of Mannar

The continental shelf between the three and twelve fathom lines, off the Ceylon coast in the Gulf of Mannar is popularly known as the Pearl Banks. Though the area of this plateau is extensive the pearl oysters are concentrated on restricted areas known as "paars". The more productive of these are the Cheval Group of paars and the Moderagam Paar. The Peria Paar and Twynam's Paar though covering larger areas are not dependable as oyster beds. The True Vankalai, Peria Paar Karai and Muthuvarathu Paars are small in extent, but have yielded oysters on a commercial scale. Although the Ceylon Pearl Banks has been commercially fished for centuries, the first scientific investigation of its pearl oysters on an intensive scale was started by Herdman in 1902 (1902-06) and later continued by Hornell (1905-41), Shipley (1904-06), Pearson (1911-33), Jameson (1912-13), Southwell (1910-14) and Malpas (1922-39).

Fishery potential of the Gulf of Kachchh

Fishery potential of the interior Gulf of Kachchh and adjacent creek regions was reported for the first time as baseline data for future ecological assessment. The experimental trawling and gill netting indicated that the inner Gulf (av. 7.8 kg/h) was three times more productive than the creek (av. 2.3 kg/h). The number of species found in the Gulf and creek were respectively 34 and 20 suggesting good biodiversity of the living resources of the area.

Effect of different rice brans on the growth of Thai silver barb (Puntius gonionotus Bleeker) in seasonal ponds

An experiment was conducted for a period of 110 days to study the effect of different rice brans on the growth of Thai silver barb (Puntius gonionotus, Bleeker) in rainfed seasonal ponds (30 m² each). Each of the ponds was stocked with 150 fish with the mean initial body weight of 2.03 ± 0.03 g. There were three treatments namely R1, R2 and R3 each having four replicates. Three types of rice bran namely coarse, auto (fine) and red were applied to the treatments R1, R2 and R3 respectively. Fish received different types of rice bran at a rate of 5% of body weight daily. The water quality parameters were found within the productive range. The results showed that treatment R1 produced significantly (p<0.05) highest growth and treatment R2 produced the lowest growth. The survival rates varied between 77 and 84% with treatment R3 producing the highest survival. However, the overall best production (1530 kg/ha) and economic return for the culture period was obtained in treatment R1 receiving coarse rice bran. The results of the present study demonstrated that the coarse rice bran resulted in better growth and production of P. gonionotus.

Species composition and abundance of different Macrobrachium species in a natural habitat of Kalu River near Titvala, Maharashtra State

Juveniles of freshwater prawns caught by the traditional cylindrical bamboo traps operated by the local fishermen in a natural habitat of Kalu River near Titvala were sampled every week during September to December 1991 and 1992, to study the composition and relative abundance of different species and their relationship with hydrobiological parameters. The juvenile catch comprised Macrobrachium rosenbergii, M. idella, M. scabriculum and M. bombayensis. Among these M. rosenbergii was more abundant followed by M. idella. It is also observed that high tide catches are more productive than those of low tides.

A record production from an integrated farming system utilising sewage enriched water

The results of experiments conducted on a pond dyke (655m²) in the Wastewater Aquaculture Division of the Central Institute of Freshwater Aquaculture, Rahara, during 1992-93 for maximising production through optimum utilisation of resources are communicated. Round the year intensive cultivation of okra (Abelmoschus esculentus), amaranth (Amaranthus gangeticus and A. viridus), water-bind weed (Ipomea aquatica), Indian spinach (Basella rubra), radish (Raphanus sativum), amaranth (Amaranthus viridis), cauliflower (Brassica oleracia var. votrytis), cabbage (Brassica oleracia var. capitota) and papaya (Carica papaya) was undertaken using the treated sewage water from fish ponds for irrigation. The pond dyke yielded 5,626.5 kg vegetable which worked out to 85.9 tons per ha per year. Multiple cropping with these vegetables excluding papaya on a 460 m² dyke recorded a production of 4,926.5 kg at the rate of 107.1t per ha/yr. An improved yearly net return of about 35% over investment could be achieved through the selection of highly productive and pest resistant vegetable crops of longer duration for integration into the system. Introduction of this type of integrated farming would enhance the overall productivity and returns from farming.

Utilisation of vegetable leaves for carp production

The results of two sets of experiments on mono-culture of grass carp (Ctenopharyngodon idella) and mixed culture of carps (grass carp 50 : catla 20 : rohu 15 : mrigal 15) fed exclusively with vegetable leaves are reported. The experiments were conducted with two replicates each in 0.02 ha ponds of Wastewater Aquaculture Division of the Central Institute of Freshwater Aquaculture, Rahara during 1991-93. Monoculture of grass carp stocked at 1000/ha demonstrated an average net production of 21.0 kg/ 0.02 ha/8 months (1501 kg/ha/yr). Mixed culture of carps stocked at 5000 /ha recorded an average net production of 22.5 kg/0.02 ha/8 months (1903.7 kg/ha/yr). Field studies revealed that water bind weed (Ipomoea aquatica) is the most preferred feed of grass carp amongst vegetable leaves followed by amaranths (Amaranthus gangeticus and Amaranthus viridis), cauliflower (Brassica oleracia var. votrytis) and cabbage (Brassica oleracia var. capitata) leaves. Through selection of highly productive leaf vegetables and suitable crop planning on fallow fish pond dykes, round the year feeding programme of grass carp has been explored. Recycling of sewage effluent for vegetable production and utilisation of vegetable leaves for fish production is considered an ideal way of integrated resource management for low cost production.

Brackish-water fishery resources

Ceylon has about 300,000 acres of coastal brackish-water areas of which about 100,000 acres constitute shallow lagoons, tidal flats, mangrove swamps and saline marshes, and the rest deeper lagoons and estuaries. While the former represent a vast potential resource with regard to fish farming, the latter are the sites of important fisheries. W. H. Schuster (1951) estimated the average natural production of Ceylon’s brackish waters to be less than 20 lbs. per acre per annum. Since then estimates have been made by the author for a rich lagoon, the Negombo lagoon, a poorly productive lagoon, the Ratgama lake (Dodanduwa) and studies are in progress of some of the other lagoons. The natural production of the Ratgama lake was estimated in 1959 to be 18.5 lbs. per acre per annum while that of Negombo lagoon was estimated in 1960 to be 65 lbs. per acre per annum. It is reasonable to estimate the average production of Ceylon's brackish-waters to be 25 lbs. per acre per annum. Thus the total production is about 3,350 tons per annum. Considering the fact that the island's present total production is 90,000 tons per annum, the brackish-waters contribute 3.7% of it. Schuster (1951) further states that the natural production in the brackish-waters of other countries is around 80 lbs. per acre per annum. In order to increase our average natural production to this value it would seem necessary to consider the nature, biology and fish resources of the brackish-waters and draw some conclusions with regard to their proper exploitation.

A brief report on a survey of the fish and fisheries of the Tana river, with special reference to the probable effects of the proposed barrages

The construction of several barrages in order to develop the hydroelectric and irrigation potential of the Tana river has been proposed and the probable effects of these developments upon the fish and fisheries of the area' has been investigated. Briefly in the highest reaches the sport fishery will be unaffected, in the middle reaches the sparse subsistence fisheries will be only slightly inconvenienced but in the terminal reaches of the river the subsistence and commercial fishing enterprises are expected to be seriously reduced by the progressive re-regulation of river-flow. However each new dam will support a new and productive reservoir fishery and with proper development the annual yield of fish from the Tana basin is expected to increase considerably.