Nutrient digestibility of angling baits for carp, Cyprinus carpio, with implications for groundbait formulation and eutrophication control     

R. ARLINGHAUS  & M. NIESAR 《Fisheries Management and Ecology》2005,12(2):91-97

Abstract  To evaluate the suitability of angling groundbaits as a fish feed and the potential for nutrient loss, the macronutrient digestibility of four groundbaits was investigated in carp, Cyprinus carpio L., using a sieving method of faeces collection and chromic oxide. Apparent digestibility coefficients (ADCs) of protein and lipids were >80% for all angling baits. ADCs of nitrogen-free extracts and phosphorus (P) differed significantly between the test diets, probably because of divergent feed compositions and ingredient treatments. The generally high digestibility estimates indicated that fish feeding on angling groundbait will benefit from this food source. The differences in nutrient digestibility suggested that type of groundbait and ingredient used will have a major effect on potential eutrophication and fish production caused by groundbaiting. The principle of groundbaits to protect the environment should be to minimise the P-content of the groundaits and maximising P-digestibility and P-retention efficiency.  相似文献   

Strategic Ideas of Greenway Construction in Ecological Zhejiang Province     

LIU Binyi XU Wenhui .Architecture  City Planning Institute ofTongji University  Shanghai  P.R.China .Garden  Art College of Zhejiang Forestry University  Linan  P.R.China 《中国林业科技(英文版)》2004,3(3):87-94

INTRODUCTIONThe Zhejiang Provincial Committee of the ChineseCommunist Party and the Zhejiang ProvincialGovernment, followed the natural law and the economicsociety law of development, has laid down the strategicdecision of "to make the ecology province constructionas the carrier, makes afforested Zhejiang" strategicdecision from 2002. From now on, within 20 years,Zhejiang Province will be a sustainable developmentprovince with developedeconomy, exquisite ecologicalenvironment, harmoni…  相似文献   

Designating a greenbelt around the city of Riga, Latvia     

Janis Donis   《Urban Forestry & Urban Greening》2003,2(1):31-39

Latvian legislation demands that forest protection belts are established around all cities and towns. The main goal of a protection belt is to provide suitable opportunities for recreation to urban dwellers and to minimise any negative impacts caused by urban areas on the surrounding environment. Legislation states the main principles to be adopted, which include the maximum area of protection belts, their integration in territorial development plans and restrictions placed on forest management activities. The largest part of the forest area around Riga is owned by the municipality of Riga, which, as a result, has two competing interests: to satisfy the recreational needs of the inhabitants of Riga, and to maximise the income from its property. In order to compile sufficient background information to solve this problem, the Board of Forests of Riga Municipality initiated the preparation of a proposal for the designation of a new protection belt.The proposal was based on the development and application of a theoretical framework developed during the 1980s. The analysis of the recreational value of the forest (5 classes of attractiveness) was carried out based on categories of forest type, dominant tree species, dominant age, stand density, distance from urban areas and the presence of attractive objects. Information was derived from forest inventory databases, digital forest maps and topographic maps. Additional information was digitised and processed using ArcView GIS 3.2. Local foresters were asked about the recreation factors unique to different locations, such as the number of visitors and the main recreation activities. From a recreational point of view and taking into account legal restrictions and development plans for the Riga region, it was proposed to create three types of zones in the forest: a protection belt, visually sensitive areas and non-restricted areas.  相似文献   

凤县休闲农业发展现状及存在问题与对策     

乔春妮  薛建宏  彭强 《黑龙江农业科学》2014,(9)

近年来,凤县转型发展休闲农业取得了巨大成功,对其发展历程进行深入研究,可以进一步促进凤县休闲农业规范快速发展,同时为我国休闲农业发展提供范例参考。详细阐述了凤县休闲农业发展的现状,对凤县发展休闲农业的优势进行了分析,就存在的问题重点从加强政府引导、理顺管理体制、制定规划标准及加大扶持力度4个方面阐明了凤县休闲农业发展的新举措,以期为凤县在休闲农业发展中获取更大的竞争优势提供参考。  相似文献   

绿道在城镇密集区的应用     

申治琼  罗言云  卿人韦 《北方园艺》2011,(23):77-80

在分析绿道理论作为线性廊道重组自然空间的基础上,以金堂公园东区为例,提出3种类型绿道的设计途径和方法,包括边缘区绿道、自行车骑游道及游步道,使金堂公园东区形成完善的绿道网络系统.绿道的交通组织、生态、文化、科普、健身、游憩等功能均得到相应体现.  相似文献   

Effect of Peat-based Container Media on Establishment of Scots Pine,Norway Spruce and Silver Birch Seedlings after Transplanting in Contrasting Water Conditions     

《Scandinavian Journal of Forest Research》2012,27(1):49-57

Abstract

Urban woodlands are the subject of complex decision-making that requires a strategic overview of the resource. This article contributes a national study of municipal woodland in Denmark. Data were collected among all Danish municipalities through a postal survey (with a response rate of 52%). As much as 83% of the woodland units were located within urban settlements or at their fringe, emphasising that municipalities are important urban woodland providers. Municipal woodland resources were typically divided into many separate units of varying size. On average, the responding municipalities owned 12.6 woodland units with an allocated area of 265 ha, resulting in a mean size of 21.5 ha. A general lack of management plans, and a significant drop in recreational facilities provided with decreasing woodland size indicate that the recreational use potential of small woodland units was largely overlooked. Municipal woodland units frequently bordered other woodland or nature areas of different ownership. Thus even small municipal woodlands can play a key role in the development of multifunctional green infrastructures in the urban landscape. Only municipalities with extensive woodland property had issued a woodland policy, and/or certified woodland management. This indicates a need for development of governance and strategic management instruments attractive to municipalities with limited woodland property.  相似文献   

Influence of terminal rig configuration on the anatomical hooking location of line-caught yellowfin bream, Acanthopagrus australis   总被引：1，自引：0，他引：1  

P. A. BUTCHER  & M. K. BROADHURST  D. REYNOLDS  S. C. CAIRNS 《Fisheries Management and Ecology》2008,15(4):303-313

Abstract  Experiments were carried out to test the dependence of anatomical hooking location on terminal rig configuration, and identify strategies by which hook ingestion can be minimised to reduce post-release mortality of angled yellowfin bream, Acanthopagrus australis (Günther). Eighty-five anglers targeted yellowfin bream using different designs and sizes of circle and J hooks and recorded technical, environmental and biological data for each landed fish. Considerably fewer fish (16.6 and 8.5%, respectively) ingested hooks than those hooked in the mouth (82.1 and 88.6%), and a greater percentage of J hooks were ingested than circle hooks or a J hook modified with a 15-mm horizontal bar. Irrespective of hook type, the rate of ingestion also declined with increasing hook weight and decreasing fish size. In cage experiments, significantly more hooks baited with natural soft baits (e.g. intestines and cephalopods) were ingested than those baited with artificial baits, crustaceans or teleosts, while in the field fewer hooks were ingested using artificial bait (e.g. bread and pellets) than terrestrial animals, teleosts, crustaceans, teleost or terrestrial animal intestines, cephalopods or polychaetes. Similarly, rigs with floats, short traces or a sinker only on the hook, along with angling in environments with at least some current reduced ingestion. Based on this study, anglers targeting yellowfin bream should be encouraged to use circle or modified J hooks and, regardless of the hook design, the largest hook size possible attached to short traces or a sinker only and hard baits.  相似文献   

基于行为观察法的游客游憩行为与环境偏好研究 ——以三明市如意湖湿地公园为例     

王梓凌杨钧宁  邹诚邓诗靖  林润泽李霄鹤 《湖北林业科技》2022,(1):44-51

以三明市如意湖湿地公园为研究对象,采用游憩行为观察法、核密度估算法、问卷调查法,分析游客的游憩行为与环境偏好及其影响因素,探究游客在三明市如意湖湿地公园中游憩的时空分布规律.结果表明:老年游客偏好在林下空间及主要景观节点处,以舒缓的游憩方式进行游憩;中青年游客的游憩目的以游览观光为主,偏好在滨水空间及景观视线良好处进行...  相似文献   

基于IPA分析的上海典型滨江公共空间游憩满意度   总被引：1，自引：0，他引：1  

刘琦  潘悦  张沚晴  王向荣 《中国城市林业》2021,(2):29-34

上海黄浦滨江是国内滨水区建设的代表,如今已完成核心段两岸公共空间贯通,但各段发展并不均衡。文章以两岸4段典型公共空间为例,对社交媒体数据进行IPA分析,得到影响滨江各段公共空间游憩满意度的主要因素,并进一步通过方差分析了解4段滨江之间的差异情况。结果表明:1)滨江公共空间整体游憩满意度较高,但多段商业服务、外部交通、管理维护因素的满意度偏低;2)满意度由高到低为:徐汇滨江>世博滨江>杨浦滨江>虹口滨江,体现3种不同的发展程度;3)不同段影响游憩满意度的主要因素不同。最后,根据研究结果对浦江两岸公共空间提出优化建议,以期为城市滨水区规划设计提供有效的技术支持和决策依据。  相似文献   

Fisheries management in inland and coastal waters in Denmark from 1987 to 1999     

G. Rasmussen  & P. Geertz-Hansen 《Fisheries Management and Ecology》2001,8(4-5):311-322

Fishing is a major recreational activity in Denmark, involving both inland and coastal waters. Anglers, aged 18–67, and amateur fishermen, aged 12–67, must hold a valid fishing permit. Fees are used for stocking, river restoration and fisheries research. All proposals for stocking inland waters require stocking plans based on the carrying capacity of the aquatic habitat in question. All stocking is undertaken using hatchery-reared fish that are the offspring, either of wild fish caught in nature for subsequent stripping, or of more or less domesticated fish stocks that have lived in captivity for several generations. Stocking is also subject to genetic guidelines. This paper reviews the status of fisheries in Danish inland waters, their regulation, socio-economic aspects, stocking, aquaculture and the main problems and trends.  相似文献