邓恩桉种源/家系两地引种试验联合分析

为了选择最适合湖南等中亚热带引种栽培的邓恩桉种源及优良家系,我们采用平衡不完全区组试验设计分别在永州市林业科学研究所和蓝山两地进行邓恩桉种源/家系引种试验。结果表明:不同种源/家系在同一试验地的表现不一,同一种源/家系在不同试验地的材积数值相差较大,种源/家系×地区的交互作用差异极显著。通过对种源/家系稳定性的测定,选出生长较快、稳定性较好的158号、181号、128号和167号等优良种源/家系,只适于在立地条件较好地方推广应用的177号、160号、146号、102号、152号、192号和163号等种源/家系,以及可以在一些立地条件相对较差地方种植的138号、176号、157号、170号和151号等种源/家系。     

Design guidelines for the Dashilar,Beijing Open Green Space Redevelopment Project

When an urban redevelopment project is planned, the design needs to reflect the preferences of the users of the planned space. In China, however, the preferences of residents have rarely been reflected in projects dealing with public places such as open green spaces in urban settings. This paper employs three independent conjoint analyses covering components of open green space, including locational conditions, physical conditions, and greenery conditions in order to propose the most preferable design for a new open green space. The results of choice simulation showed that the users prefer the private garden style to the general public park style for the new open green space in Dashilar. Our research with three independent conjoint analyses is expected to provide specific guidelines for open green space design as a whole, which is intended to satisfy potential users of the space.     

城郊生态休闲农业发展的思考——以怀化市为研究对象

休闲农业是农村第一产业的三产业化,是农业和旅游业有机结合的一个新兴产业,是农业产业化的一种新选择、新亮点。以生态休闲农业为代表的休闲基地,现已成为城乡居民交流合作、互通信息、丰富精神生活的重要载体。通过对怀化生态休闲农业发展现状、资源优势及存在问题的分析,为发展生态休闲农业,推进怀化市社会主义新农村建设提出几条建议。     

几种番荔枝耐淹能力的初步比较

以阿蒂莫耶番荔枝（A. atemoya）、普通番荔枝（A. squamosa）、山番荔枝（A. montana）和圆滑番荔枝（A. glabra）1年生盆栽实生苗为材料,进行为期一年的连续性和周期性淹水试验,初步结果表明：阿蒂莫耶番荔枝和普通番荔枝是不耐淹的树种,在两种淹水处理情况下,均没有新根产生,地上部生长不正常,叶片萎蔫;山番荔枝是耐淹的树种,在两种淹水处理情况下,所有植株根颈部都能产生新根;圆滑番荔枝既耐淹又适于水中生长,经12个月的淹水处理后,株高和主干横径均超过对照,是一适合湿地生长的树种。     

Land use and forest cover on private parcels in the Upper Midwest USA, 1970 to 1990

This paper analyzes the interactions between land use and forest cover in the Upper Midwest, USA from 1970 to 1990. New data are presented and interpreted to evaluate the effects of land-use changes, especially abandonment of agriculture and dispersed development, on forest cover throughout the region. Forest-cover data were collected from Landsat satellite imagery and land use was interpreted from aerial photographs for land parcels, based on archival maps of land ownership. In general, forest cover increased throughout the region and throughout the period. Simultaneously, the area used for agriculture declined, much of it being converted to natural uses, and the area of land in low density residential development increased. Forest cover increased most rapidly on low density residential lands and in counties in which a large percentage of homes were for seasonal use (i.e., vacation homes). The data suggest that the transformation of the region from an extractive (i.e., forestry and agriculture) to a recreation-based service economy has played a significant role in the increasing forest cover observed throughout the region. This revised version was published online in July 2006 with corrections to the Cover Date.     

Utilization of correlation network analysis to identify differences in sensory attributes and organoleptic compositions of tomato cultivars grown under salt stress

In tomato production, salt stress is applied to improve the fruit quality. The change in sensory attributes and organoleptic compositions in salt-stressed tomato fruits have been extensively studied; however, little is known about their interaction with each other. Correlation network analysis provides a visual representation of biological systems and useful knowledge for metabolic data analysis of tomato fruits. The aim of this study is to identify the cultivar differences in sensory attributes and organoleptic compositions of tomato fruits grown under salt stress and to elucidate their interaction among different cultivars using correlation network analysis. Salt stress was applied by adding 100 mM NaCl to the nutrient solution. Fruits were harvested at red-ripe stage and used for the evaluation of sensory attributes such as sweetness, sourness, umami, and tomato like, and organoleptic compositions such as sugar, organic acid, amino acid, and sodium ion contents. Almost all of the sensory attributes and organoleptic compositions of the fruit were significantly high in salt-stressed cultivars compared to non-stressed cultivars, and significant differences were also observed among cultivars. The correlation network analysis of the control fruit showed that compared to other traits, sugar is one of the key traits for improvement of tomato fruit quality based on high connectivity and betweenness centrality. In contrast, a high degree of positive connectivity was not observed between organoleptic compositions and sensory attributes in the salt-stressed fruit network. These results indicate that the relationship between sensory attributes and organoleptic compositions in fruits were different between the control and salt-stressed cultivars, suggesting that the salt-stressed fruit may have a different circuit of relationship compared to control. Furthermore, based on the increase ratio (salt stress/control) network results, we suggest that the increased sugar, organic acid, and amino acid contents may have contributed to the salt stress-induced enhancement of sensory attributes.     

淹水胁迫及胁迫解除对甜瓜光合色素和光合特性的影响

以耐涝性差异显著的两个甜瓜品系T106 和T241 为试验材料,采用双套盆法进行淹水胁迫,研究了淹水胁迫及胁迫解除对甜瓜幼苗光合色素和光合特性的影响。结果表明：随着淹水胁迫时间的延长,2 个甜瓜品系的叶绿素a、叶绿素b、总叶绿素、类胡萝卜素含量以及净光合速率、蒸腾速率、气孔导度、胞间CO₂ 浓度均呈下降趋势,且T106 各项指标的下降幅度均低于T241;在淹水胁迫相同天数时,T106 的各项指标均高于T241;在淹水胁迫解除后,2 个甜瓜品系的各项指标均上升,且T106 的上升幅度大于T241。     

Vegetation density of urban parks and perceived appropriateness for recreation

There is a growing body of evidence indicating that exposure to, and activities in, nature have beneficial effects on human health. Since a majority of people in many countries live in urban areas, availability and use of urban green areas is of increasing importance to public health. In the present study we measured urban residents’ (Trondheim, Norway) recreational preferences for urban park landscapes varying in vegetation density, and aimed at an identification of background variables and environmental value orientations that we hypothesised to influence such preferences. The results showed that moderately dense scenes received the highest preference ratings. Socio-demographic variables and value orientations predicted preferences for moderate to densely vegetated scenes: A curvi-linear effect of age of respondents was found, with subjects in their mid-40s expressing a higher preference for moderate to dense vegetation, compared to younger and older subjects. Preference for moderate to dense vegetation also increased as the educational levels of the respondents increased. The preference was lower among people living in apartment blocks, relative to those living in detached houses. Of attitudinal and value-related variables, interest in wildlife, and pro-ecological value orientation (measured with the NEP scale) predicted preference for urban parks with moderate and dense vegetation. The existence of preference for relatively dense vegetation in urban parks in segments of the population has consequences for the designing of urban parks in Norway.     

Perceived access to recreational/green areas as an effect modifier of the relationship between health and neighbourhood noise/air quality: Results from the 3rd European Quality of Life Survey (EQLS, 2011–2012)

The present study tests the hypothesis that better access to recreational/green areas modifies the adverse effects of neighbourhood noise and air quality on health. We re-analysed the cross-national representative sample of the 3rd European Quality of Life Survey (EQLS) (2011–2012). Data were available on self-rated health, neighbourhood noise, air quality, access to recreational/green areas, and other sociodemographic and neighbourhood covariates. The substantive analyses were based on weighted logistic regression with clustered standard errors. Overall, reporting major neighbourhood problems with noise and air quality was associated with higher risk for poor self-rated health, and this risk was higher among participants not using recreational/green areas in their neighbourhood or reporting a difficult access to those areas. There was a statistically significant effect modification across some exposure − access scenarios, but it was clearer for air quality than it was for noise. Thus, this exploratory study sets the basis for future research on the subject matter.     

Urban forest usage and perception of ecosystem services – A comparison between teenagers and adults

Urban forests provide multiple ecosystem services for a range of user groups. However, teenagers are commonly underrepresented in studies about forest recreation and cultural ecosystem services. This paper examines teenagers' forest use and perception of ecosystem services compared to adult populations. We used an online panel survey to elicit motives for forest visits, frequency of visits, forest activities and constraints for visitation, and what ecosystem services participants expect from forests more generally. We then elicited perceived cultural ecosystem services of different forests by showing participants photographs of forest inventory plots for which we had detailed measures of physical forest characteristics to statistically assess the influence of forest characteristics and other parameters on perceived cultural ecosystem services. Results show that teenagers visit forests less often and also differ from adults in their preferences and activities, their motives for forest visits and reasons for not visiting forests. Teenagers exhibit more social and active forms of forest use, whereas adults use forests in more contemplative ways. Perception of cultural ecosystem services on forest photos was influenced by individual factors such as motives for forest visits, preferences, importance of forest during childhood and socio-demographic factors. Environment- and forest-related factors such as forest type, stand structure and single elements such as root plates and stumps had an influence on ecosystem service perception. We conclude that teenagers have different needs than adults concerning the provision of cultural ecosystem services from forests and therefore should be considered as a user group of its own in the management of recreational forests.