A study of environmental conflict: the economic value of Grey Seals in southwest England

This paper reports an analysis of a typical case of negative bilateral externality – a situation in which two legitimate activities, fishing and wildlife conservation, each give rise to damages to the other party. The Cornish fishing industry believes that its annual profits are reduced by an estimated £100 000 because of the damage by seal populations to caught fish. About 80 individuals belonging to the Cornish Grey Seal population (of about 400 specimens) are killed as a by-catch of trawling. Thus, the status quo is clearly inefficient: seals are perceived to damage fish and fishermen definitely damage seals. The biological dynamics of the seal population is not absolutely clear, so that a precautionary approach requires that care should be taken to avoid the risk of damaging the population in an irreversible way. Moreover, public opinion considers seals to be a high value flagship species. One of the goals of any conflict resolution should be to capture the economic value of seal conservation – i.e. to convert conservation benefits into resource flows – and use at least part of it in order to create incentives for a more efficient allocation of resources. The authorities should invest in seal conservation (i.e. compensating fishermen) if the benefits deriving from conservation exceed the opportunity costs of conservation. Such a solution clearly requires that the conservation benefits be estimated. To investigate the economic value of seal conservation a contingent valuation study is carried out. A contingent valuation study utilises a questionnaire approach and part of the questionnaire seeks to elicit individuals' willingness to pay (WTP) for a change in the state of some good or asset, in this case seal conservation. Due to resource limitations, the sample size of those interviewed in the study reported is small, so that we cannot be extremely confident about the results. However, they are consistent with those derived from similar studies on flagship species. Results show a mean WTP for recreational use of seals of about £8 per person for the option of seeing seals in a specialised sanctuary for seals recovered from accidents, and closer to £9 for seeing seals in the wild. The annual non-use value of seals – i.e. value unassociated with actual viewing – was found to be £526 000 in the most conservative estimation, aggregated over the Seal Sanctuary visitors. This economic potential could be realised in several ways and used to compensate fishermen for changing fishing techniques, targets and fishing areas. Finally, we investigate the role the Seal Sanctuary is playing in this context and some policy suggestions are discussed.     

次生栎林蒸腾强度与生态因子的关系

采用多元回归分析和灰色关联分析方法,探讨下蜀次生栎林蒸腾强度与生态因子的相关关系。研究认为用二次工咕次多项式回归方程和指数回归方程拟合更能反映各生态因子在整个生长季中与蒸腾强度关系的性质。影响蒸腾强度的主要生态因子是温度和净辐射;其次是空气相对湿度和土壤热流通量;风速和土壤含水率的影响很小。灰色关联分析与多元回归分析的结论一致。研究结果为进一步阐明次生栎林的结构和功能提供了理论基础。     

Detection of Botrytis cinerea by loop-mediated isothermal amplification

Aims: To develop a sensitive, rapid and simple method for detection of Botrytis cinerea based on loop‐mediated isothermal amplification (LAMP) that would be suitable for use outside a conventional laboratory setting. Methods and Results: A LAMP assay was designed based on the intergenic spacer of the B. cinerea nuclear ribosomal DNA (rDNA). The resulting assay was characterized in terms of sensitivity and specificity using DNA extracted from cultures. The assay consistently amplified 65 pg B. cinerea DNA. No cross‐reactivity was observed with a range of other fungal pathogens, with the exception of the closely related species Botrytis pelargonii. Use of a novel real‐time LAMP platform (the OptiGene Genie I) allowed detection of B. cinerea in infected rose petals, with amplification occurring in <15 min. Conclusions: The LAMP assay that was developed is suitable for rapid detection of B. cinerea in infected plant material. Significance and Impact of the Study: The LAMP method combines the sensitivity and specificity of nucleic acid‐based methods with simplified equipment and a reduced reaction time. These features make the method potentially suitable for on‐site use, where the results of testing could help to inform decisions regarding the storage and processing of commodities affected by B. cinerea, such as cut flowers, fruit and vegetables.     

香菇单孢杂交子代群体灰色关联度和ISSR分析

以香菇Lentinula edodes栽培菌株秋6和K95-1为亲本,通过单孢菌株配对杂交获得21个杂交子,观察杂交子及亲本菌丝体生长情况,进行栽培出菇试验。采用灰色关联度分析法,对9个正常出菇的杂交子从8个性状方面进行综合评价,结果表明,杂交子QK-8和QK-15关联度仅次于亲本秋6,农艺性状和子实体性状表现最好。采用ISSR技术对21个杂交子及亲本进行DNA多态性聚类分析,单孢杂交后代遗传分化十分明显,归于同一类群的杂交子在菌丝生长、子实体形态和农艺性状等方面常表现相似,ISSR分析能为优良杂交子初步筛选提供重要参考。     

Factors Affecting Landscape Occupancy by Fishers in North-Central British Columbia

ABSTRACT To better understand distribution and density of fishers (Martes pennanti) in industrial forests of north-central British Columbia, Canada, we examined factors affecting the probability of a potential home range being occupied by 10 radiotagged resident fishers in the Sub-Boreal Spruce biogeoclimatic zone between 1996 and 2000. Percentage of a home range in wetlands and recently logged (within past 12 yr) best predicted likelihood of occupancy by each fisher. Probability of a home range area being occupied by a resident fisher decreased with increasing amounts of wetlands and recent logging present in the area. We estimated that a 5% increase in wetlands or recent logging decreased the relative probability of occupancy of a potential home range by 50%. The accelerated rate of timber harvest in forests affected by mountain pine beetle (Dendroctonus ponderosae) infestations may have substantial implications for the ability of the landscape of central British Columbia to support sustainable populations of fishers.     

The activity budgets and activity patterns of sympatric grey rhebok and mountain reedbuck in a highveld grassland area of South Africa

Behavioural observations were carried out on grey rhebok and mountain reedbuck at Sterkfontein Dam Nature Reserve, South Africa, for a period of 1 year between May 2001 and April 2002. Four harem herds of grey rhebok, five territorial male mountain reedbuck and female mountain reedbuck (herds grouped as one individual) were monitored to determine activity budgets and activity patterns. Both species spent more time feeding in the late afternoon during relatively cool temperatures, and more time resting in the middle of the day during relatively high temperatures. Statistical comparisons between the two species of the percentage time feeding and resting found no differences between them, although mountain reedbuck spent more time resting overall than grey rhebok. Both species were active at night.     

Survival of Botrytis cinerea in Soil in South-Eastern Spain

The survival of Botrytis cinerea in sterile and unsterile soil at different temperatures and relative air humidities was investigated in south‐eastern Spain. Conidia survived only 7 days at 40^°C but, depending on relative humidity, for 30–90 days at 22^°C. High air humidity (95%) was needed to maintain soil humidity (8%) at a level that favoured conidial survival. Conidia survived better in sterile soil than in unsterile soil, probably because of the presence in the latter of soil microorganisms antagonistic to B. cinerea. Survival of conidia in environmental conditions simulating those in a greenhouse was less than 28 days. Results showed that B. cinerea conidia cannot survive over summer in south‐eastern Spain, and other primary sources of inocula are discussed.