洲际背包客中国出入境口岸选择

本文首次讨论洲际背包客在华出入境口岸选择偏好。在对西安、阳朔两地洲际背包客进行旅游市场实地亲身调查的基础上,总结了背包客对北京、香港、上海、广州中国四大进出境口岸城市的旅游访问率;讨论了对各口岸城市的选择行为并分析了影响口岸选择的因素;在Leiper双目的地旅游系统地理要素模型的基础上,构建了洲际背包客旅游系统地理要素模型;提出不同旅游偏好的洲际背包客对相应类型顶尖级旅游吸引物先睹为快的倾向。     

沿海防护林体系现状分析与创新立法保护探讨

通过对沿海防护林体系现状、存在问题及法律保护现状分析的基础上,提出建立起以国家专门立法为主的法律法规保障体系,将沿海防护林体系及其生态系统的保护纳入相应法律制度;完善法律责任制度,严格林地保护管理,明晰产权,维护国家对滨海湿地所有权和使用者的合法使用权等,从而实现对沿海防护林体系的有效保护,充分发挥沿海防护林体系的生态、经济和社会效益。     

发展小城镇建设促进我国农村经济发展

小城镇以其特有的功能和作用在我国农村经济发展中占有重要地位.改革开放以来,我国农村的小城镇建设取得了巨大的成就,但也存在着很多问题,如规模较小、布局不合理、社会保障体系不完善、缺乏必要的产业支撑等.从小城镇的概念、功能和作用入手,对我国农村在小城镇发展过程中存在的诸多问题进行分析,并提出相应的对策.     

草坪在城市园林绿化中的作用及其发展研究

草坪在现代城市园林绿化中具有重要作用，如维持城市生态平衡、发展社会效益、美化环境等。本文在阐述草坪综合功能的同时，又从因地制宜地开发草坪资源，健全市场，应用新技术等方面就草坪业的发展进行了研讨。     

基于稳定同位素的江苏近海金乌贼摄食生态研究

为进一步掌握江苏近海金乌贼(Sepia esculenta)种群生活史特征，根据在江苏沿海港口所采集的样本，利用碳氮稳定同位素分析法对金乌贼的摄食生态及营养生态位进行了研究。结果表明，金乌贼雌、雄群体间 13C和 15N值均不存在显著性差异；金乌贼的 值与胴长之间相关性不显著， 值与胴长之间存在显著相关性；雄性金乌贼营养生态位宽度（SEAc=0.57‰2）与雌性（SEAc=0.63‰2）无明显差异，雌性略大于雄性，且两者高度重叠（0.62）。同位素聚类分析显示，可将金乌贼个体分为75~114mm、115~184mm和185~204mm三个胴长组；185~204mm胴长组营养生态位宽度最大（SEAc=1.77‰2），75~114mm胴长组营养生态位宽度最小（SEAc=0.39‰2）；仅75~114mm和115~184mm胴长组间生态位重叠率为中度重叠（0.34），其余胴长组间生态位重叠率低。分析认为，金乌贼δ13C值的变化主要受同位素基线值和金乌贼洄游模式影响，而δ15N值的变化主要受金乌贼摄食作用影响；雌性和雄性金乌贼群体之间食物资源和栖息地利用高度相似；不同发育阶段的金乌贼在营养生态位上具有明显差异。     

Water circulation, groundwater outflow and nutrient dynamics in Mida creek, Kenya

The relationship between physical hydrodynamic processes and nutrients dynamics was investigated in Mida creek, a groundwater influenced mangrovefringed creek in Kenya between March 1996 and May 1997. The research involved spot and timeseries measurement of nitrate–nitrite, ammonia, silicates, phosphates, salinity, temperature, sealevel as well as tidal currents at seven stations located in the front, middle and backwater zones of the creek. Groundwater level as well as total dissolved solids' concentration, salinity, temperature and nutrients' concentration were also measured once every month in shallow wells (watertable<5m) located in the upper region of the creek. Results of the study show that nutrient concentrations vary with the tide and that, though there is no river drainage, they are of the same magnitude as in mangrove creeks with substantial river runoff. The peak concentrations of NH ₄ ⁺ –N (5.45M), NO ₂ –NO ₃ (5.63M), PO ₄ ^3– –P (0.58M) and SiO ₃ ^2– –Si (81.36M) in the creek occurred during flood tide, 2–3h before high waters. The (NO ₂ ^– + NO ₃ ^– )–N concentrations declined rapidly during ebb tide, reaching the minimum levels during low water. Contribution of groundwater seepage to the net nutrients flux (particularly on nitrite–nitrates) is largest in dry seasons. The study shows that groundwater outflow sustains the mangroves during periods of severe salinity stress and nutrients deficiency in dry seasons. This is essentially by limiting salinity increase and by boosting nutrient supply in dry seasons.     

Spatially Explicit Evaluation of Local Extractive Benefits from Mangrove Plantations in Bangladesh

Mangroves worldwide provide a wide range of ecosystem services utilized directly and indirectly by local peoples. Between 1966 and 2001, Bangladesh established approximately 148,000 ha of mangrove plantations in coastal areas within the Barisal and Chittagong Divisions. Though erosion and human encroachment and conversion have removed over two-thirds of these stands, the Forest Department has continued to undertake new plantation activities.

To investigate how and to what degree people directly utilize these mangroves, I conducted 340 household surveys across eight coastal villages located in close proximity to established plantations. The predominant direct use of the mangrove plantations by local rural communities is the extraction of detritus and nonmain stem material (e.g., limbs, leaves) for combustible fuel. This study uses household foraging distances to estimate and map net value densities based on reported market prices of extracted goods. The average extractive value of mangrove plantations is Tk 2,300 ha^?1 yr^?1, ranging among the villages from 300 to Tk 27,400 ha^?1 yr^?1, with values concentrated closer to the village. Cost-benefit analyses suggest that direct use values alone have justified the establishment and management of previously planted stands. However, other indirect values must be taken into account if these areas are to merit additional plantations.     

海涂哺鸡竹与角竹春笋产出,笋株重量变化的比较研究

在海涂含盐土壤中，角竹造林后成园快，笋单产高于哺鸡竹；角竹笋期５月１４日～６月１０日，哺鸡竹为４月２９日～５月１０日，盛笋期在出笋中前期，延续约１０～１２ｄ；竹笋单株重量哺鸡竹明显大于角竹，笋株粗重期在出笋初期和中前期，比盛笋期约早３ｄ，延续时间同盛笋期。因此，宜扩大角竹造林面积，延长供笋期，多产市场淡季笋，以获得更佳的效益。     

发展观赏竹种繁荣沿海经济

从观赏竹的外形特征、内涵意义以及在园林绿化、园林建筑上的应用等方面对其观赏、利用价值作了论述;对在沿海地区发展观赏竹林的必要性及有利的自然、经济条件作了具体分析;将沿海地区(以福建为例)的观赏竹分为4大类进行具体应用;对在沿海地发展观赏竹种,繁荣沿海经济提出建议。     

海岸基干林带作业设计新理念探索——以浙江瑞安市海岸基干林带建设为例

以浙江瑞安市海岸基干林带建设为例,在基干林带内部结构方面,提出海岸基干林带为生态系统聚集体的新理念,把生态系统作为构成海岸基干林带的基本单元。瑞安市海岸基干林带通过扩充基干林带规模,增加水面空间,形成林水交融的多系统综合体,显著提高基干林带的防风滞浪滞洪功能;在基干林带功能定位方面,提出在强化基干林带防风护岸基本功能的前提下,加强基干林带滞洪泄洪和景观美化功能,建设具有复合功能的新型基干林带。瑞安市海岸基干林带充分利用林水交融的景观特点,加强观花、观叶、观果树种的营造,实现休闲娱乐空间在防护林带中的合理布局,不仅赋予基干林带生态防护功能,而且使其具有独特的生态旅游功能,与基干林带周边发达的社会经济条件相衔接,提高基干林带的自我经营能力。