度假酒店景观评价研究——以杭州西溪悦榕庄为例   总被引：1，自引：0，他引：1  

邵宁  汤晓敏 《上海交通大学学报(农业科学版)》2015,(4):88-96

度假酒店正受到越来越多游客的青睐。作者以"社会调查研究"理论为依据,选出最具代表性的江南地区度假酒店——杭州西溪悦榕庄作为研究对象并采用AHP层次分析法和综合指数法等数理方法建立度假酒店包括美感度、功能性、文化性和游憩度在内的4个准则层和17个因子层的景观质量评价模型。通过问卷调查获取数据,得出悦榕庄景观综合质量等级为优,其中Ⅰ级(优)因子14项、Ⅱ级(良)因子3项。同时,总结得出该酒店景观在美感度和文化性上具有一定优势,而游憩度上存在不足,并提出了丰富室外活动空间等景观提升对策。此次研究对度假酒店景观领域做了较为全面、深入的剖析,建立了度假酒店景观质量评价体系,针对江南地区特色度假酒店——悦榕庄景观设计提出了建议,为同类酒店景观的优化提升及设计提供了一定借鉴。  相似文献   

Age and growth of yellowstriped butterfish, <Emphasis Type="Italic">Labracoglossa argentiventris</Emphasis>, around Izu Oshima Island     

Shingo?Watari  Junji?Yonezawa  Sakutaro?Yamada  Eiji?TanakaEmail author  Toshihide?Kitakado 《Fisheries Science》2005,71(1):86-94

ABSTRACT:   Age and growth of the yellowstriped butterfish, Labracoglossa argentiventris , around Izu Oshima Island were studied using a total of 1450 fish. Age was determined by counting the edge of the opaque zones as a ring mark on sectioned sagittal otoliths. Formation of the first ring was observed during spring or summer, corresponding to 1.5 years after hatching. Thereafter, one ring was formed each year in the same season as the previous year. The growth of the butterfish was rapid until 2 years of age. The maximum likelihood method was applied to the age and length data for estimating parameters in von Bertalanffy, Gompertz, and Logistic growth models. The selected model, based on the Akaike Information Criterion, was the von Bertalanffy growth model, which indicated differential asymptotic length and variance by sex.  相似文献   

What makes fisheries data informative?     

Arni Magnusson  & Ray Hilborn 《Fish and Fisheries》2007,8(4):337-358

Informative data in fisheries stock assessment are those that lead to accurate estimates of abundance and reference points. In practice, the accuracy of estimated abundance is unknown and it is often unclear which features of the data make them informative or uninformative. Neither is it obvious which model assumptions will improve estimation performance, given a particular data set. In this simulation study, 10 hypotheses are addressed using multiple scenarios, estimation models, and reference points. The simulated data scenarios all share the same biological and fleet characteristics, but vary in terms of the fishing history. The estimation models are based on a common statistical catch‐at‐age framework, but estimate different parameters and have different parts of the data available to them. Among the findings is that a ‘one‐way trip’ scenario, where harvest rate gradually increases while abundance decreases, proved no less informative than a contrasted catch history. Models that excluded either abundance index or catch at age performed surprisingly well, compared to models that included both data types. Natural mortality rate, M, was estimated with some reliability when age‐composition data were available from before major catches were removed. Stock‐recruitment steepness, h, was estimated with some reliability when abundance‐index or age‐composition data were available from years of very low abundance. Understanding what makes fisheries data informative or uninformative enables scientists to identify fisheries for which stock assessment models are likely to be biased or imprecise. Managers can also benefit from guidelines on how to distribute funding and manpower among different data collection programmes to gather the most information.  相似文献   

幼鳜对蛋白质日需要量及投饵率的初步研究   总被引：1，自引：0，他引：1       下载免费PDF全文

吴婷婷  徐跑 《水产学报》1988,12(1):63-66

蛋白质和脂肪等是鱼类生长和维持生命活动必不可少的营养素，尤其蛋白质极为重要。研究鱼类对蛋白质的需要量，不仅可满足鱼类的需要、加速鱼类的生长，而且可提高鱼类对蛋白质的利用率。国内外通常采用蛋白质梯度法测定鱼类的蛋白质需要量，但该法仅适用于摄食人工饵料的鱼类。鳜鱼终身以活鱼虾为饵料，所以蛋白质梯度法不适于测定鳜鱼对蛋白质的需要量。为此，我们采用分阶段饲养法，即在幼鳜不同生长阶段定量地投喂其适口饵料，以幼鳜个体增重、饵料系数和蛋白质利用率计算出幼鳜对蛋白质的日需要量及投饵率。  相似文献   

内部切片法测定淡水贝类的年龄   总被引：2，自引：0，他引：2       下载免费PDF全文

华丹 《水产学报》2001,25(5):413-418

采用外部生长线估算法测定淡水贝类年龄具有局限性，对年龄偏大或生长较慢的品种不适用。本文介绍一种新的方法-内部切片法，是精确和准确测定贝类年龄的有效方法。通过对美国的两种淡水贝类扇贝和厚实珍珠贝进行内部切片法和外部生长线估算法的研究和实验数据的统计分析，证明内部切片法的结果更代表贝类的实际年龄。同时，还分析了淡水贝壳类年龄、长度、高度之间的相互关系。  相似文献   

The Welsh Torgoch (Salvelinus alpinus): a short review of its distribution and ecology     

I. D. McCarthy 《Ecology of Freshwater Fish》2007,16(1):34-40

Abstract –  The Arctic charr Salvelinus alpinus (L.), or Torgoch ('red belly') in Welsh, is found in seven lakes in North Wales comprising three native populations (Bodlyn, Cwellyn and Padarn) and four translocated populations (Cowlyd, Diwaunedd, Dulyn and Ffynnon Llugwy). The Welsh charr populations have not been studied much, but the available data are summarised in this short review. Analysis of stomach contents of the native charr populations shows that they are planktivores feeding mainly on cladocerans and copepods. Adult fish attain a size of 14–24 cm (fork length) and fecundity is low (100–800 eggs per female). The available growth data reveal that Welsh charr grow at a similar rate and attain a size similar to most other planktivorous charr populations that have been studied in the UK. Genetic studies using allozymes indicate that the three native populations are distinct from each other.  相似文献   

Planktivory and diet-overlap of densely rakered whitefish (Coregonus lavaretus (L.)) in a subarctic lake     

K. Kahilainen  E. Alajärvi  H. Lehtonen 《Ecology of Freshwater Fish》2005,14(1):50-58

Abstract –  Three sympatric whitefish ( Coregonus lavaretus (L.)) forms, one being pelagic and two benthic, segregate available habitat and food resources in subarctic Lake Muddusjärvi, northern Finland. Zooplankton availability in the lake, food composition, diet-overlap and growth of densely rakered (DR) whitefish were examined during June to September to explore the reasons for the small individual size of the pelagic form. DR whitefish used zooplankton as main food item and prey selection followed zooplankton species density proportions in the lake. Zooplankton density and water temperature was highest in July–August. The average lengths of Bosmina spp., Daphnia spp., Calanoida and Cyclopoida in DR whitefish stomach were higher than in zooplankton sample during June–September, except Calanoida in June. Diet-overlap between DR whitefish age groups was high at all months indicating intercohort resource competition. DR whitefish reached sexual maturity at 3 years of age and at the length of 12 cm, after which somatic growth almost ceased. Reason for the small average size and slow growth of DR whitefish were connected to high diet-overlap between age groups and early sexual maturation.  相似文献   

Age structure of Pacific saury Cololabis saira based on observations of the hyaline zones in the otolith and length frequency distributions     

Satoshi Suyama  Yutaka Kurita  Yasuhiro Ueno 《Fisheries Science》2006,72(4):742-749

ABSTRACT:   The ages ( n  = 11 178) and length frequency distributions ( n  = 173 300) of Pacific saury Cololabis saira caught from September to November in 1989–2000 were examined. Most specimens were determined as either age 0 or 1 based on the number of annual rings in the otolith. The knob lengths (length from the tip of the lower jaw to the posterior end of the muscular knob on the caudal peduncle) at which 50% of the fish were age 1 ranged 277.8–304.7 mm. Analysis of length frequency distribution was also useful to divide the knob lengths of the two groups. The modal lengths of age 1 fish ranged 303.9–325.9 mm.  相似文献   

Changing patterns in insect pests on trees in The Netherlands since 1946 in relation to human induced habitat changes and climate factors—An analysis of historical data     

Leen G. Moraal  Gerard A.J.M. Jagers op Akkerhuis 《Forest Ecology and Management》2011,261(1):50-61

In The Netherlands, insect pests on trees and shrubs are being monitored continuously since 1946. During these years, almost all insect pest populations showed marked changes, which may be the result of changes in forest management, shifts in forest composition, climate change and the arrival of new pests from the Mediterranean region or from other continents. In order to generate hypothesis about possible relationships between species ecology and environmental factors, we have analyzed 61 years of population development of the 98 most abundant species in the database while paying attention to life history traits and preferred host plants. The 22 species with infestations lasting a few years only were excluded from the analysis. Of the remaining 76 species, 18 were present over the entire observation period of 61 years. Of the other species, 27 showed a decline and 31 showed an increase. On coniferous trees most species showed decreasing populations. Increasing populations were found most on deciduous trees. Not directly climate-related factors such as changes in forest age, tree composition and forest management were identified as the most important causes for the fluctuations in pest insect populations. Climate change is a possible driver of the population increase in Thaumetopoea processionea, Haematoloma dorsatum and of the population decrease in Euproctis chrysorrhoea. The recently increasing exotic species Eupulvinaria hydrangeae and Pulvinaria regalis were exclusively found on trees in cities, presumably in relation to the higher temperatures of the urban habitat.  相似文献   

Baobab (Adansonia digitata L.) fruit production in communal and conservation land-use types in Southern Africa     

Sarah M. Venter  Ed T.F. Witkowski 《Forest Ecology and Management》2011,261(3):630-639

Baobab fruit are harvested and used throughout Africa as an important source of food and are sold to generate income. Commercial use is increasing rapidly as derivatives of the fruit such as baobab seed oil and fruit pulp are being exported to Europe and North America. The cash derived from the sale of fruit support thousands of rural people. This study examines baobab fruit yields in an area being harvested for commercial use. It represents baobab populations and harvesting scenarios typically found in Southern Africa and is the first study in Africa to combine demographic and production data in determining baobab fruit yields.Fruit production was examined across five land-use types (nature reserves, rocky outcrops, plains, fields and villages) and over three consecutive years. Factors assessed included differences in life-stage, tree size, land-use type, inter-annual variation and quantifiable fruit predation.Results showed that adult trees produced 8 times more fruit than sub-adult trees. Fruit production fluctuated between size-classes and exhibited weak linear and logarithmic trends between fruit production and dbh and crown volume, respectively. There was high variation between trees with 41% of adult trees consistently producing <5 fruit per year, which we classed as ‘poor-producers’. Different land uses showed no significant differences in fruit production per tree, but where baboons were present, in nature reserves and rocky outcrops, predation of immature fruit resulted in up to 85% fruit loss. Villages and fields had the highest tree density and yielded the most fruit/ha. Inter-annual variation was significant with a two and a half fold difference between the highest and lowest year.The results of this study are important for economic planning and management and are key to determining sustainable harvesting levels of baobab fruit in Southern Africa.  相似文献