会展与酒店效益及配置关系研究--以中国出口商品交易会(广交会)为例

本文以中国出口商品交易会(广交会)为案例,剖析会展业对城市酒店业的空间结构影响、效益带动作用以及参展人员对酒店的行为偏好,探讨其与城市酒店配置的关系。研究表明,广交会对广州酒店业意义深远,不仅在广交会展馆附近形成了广州星级酒店的空间聚集带,而且提升了广州酒店业整体经济效益。研究还显示酒店受益幅度遵从距离衰减规律;参展人员对高中档酒店需求旺、其中五星级和三星级酒店更受青睐;国内外参展商的住宿需求偏好各异;高档酒店集聚了主要的利润等。这些特征对研究城市会展与酒店配置的关系提供了重要依据。     

Pollen evidence for major shifts in forest composition since the mid‐nineteenth‐century in the vicinity of Sudbury,Ontario

Numerous anthropogenic stressors have impacted the region surrounding Sudbury, Ontario, leading to pronounced vegetation and landscape change. Few long‐term records exist to understand the nature or timing of this change. We use pollen analysis from radiometrically dated sediments of Clearwater Lake to compare pre‐ and post‐settlement vegetation. Beginning ～1850 CE, the record shows major shifts in forest composition, coincident with settlement and the beginnings of lumbering. These changes are unprecedented for the past ～5000 years, and consist of increases in diversity and abundance of deciduous tree taxa and herbaceous disturbance indicators. While evidence of mining appears as early as 1900 CE, little effect is seen in the pollen record until ～1930 CE, when sedimentation rates increased and acidification of the lake also began. At this time, further increases in palynological disturbance indicators and minimum sediment organic matter levels indicate the period of maximum vegetation loss. As a result of reduced emissions since the 1970s, water quality began to improve in Clearwater Lake and there are some decreases in the abundances of shade‐intolerant disturbance indicators in the pollen record. However, the fact that the pollen assemblages do not resemble those prior to 1850 suggests lasting vegetation changes.     

Preservation of old‐growth forests: a case study of Big Timber Park,Whistler, BC

This paper explores the concepts of old‐growth forests, preservation and natural disturbance and demonstrates how contemporary biogeographic theory contributes to successful preservation of old‐growth forests. The case study analyzes the composition, structure, age and growth histories of trees in Big Timber Park, Whistler, British Columbia. Composition. The structure of the forest was diverse and tree ages ranged from 122 to 305 years. The densities of large old Douglas‐fir, shade‐tolerant trees and all snags are indicative of old‐growth forests; however, maximum tree diameters and densities of large snags and logs do not meet quantitative criteria for old‐growth forests. The abundance of tree regeneration and understory vegetation are relatively low. We conclude that some aspects of Big Timber Park are transitional between the mature and old‐growth stages of forest development. In the future, fine‐scale canopy gaps caused by tree senescence and interactions among insects, pathogens and wind are expected to dominate stand dynamics. Forest structure will become increasingly complex, exemplifying the dynamic nature of old‐growth forests. To successfully preserve Big Timber Park and La préservation des forêts other old‐growth forests in Canada requires understanding of natural disturbances. Preservation and the criteria and indicators used to measure successful preservation must explicitly include elements of natural change.