“生态优先”森林经营思想之我见

回顾了森林经营思想发展演变的历史及"生态优先"经营思想提出的背景;阐述了"生态优先"的理论基础是可持续发展理论、生态经济理论及复合生态系统理论,其实质是在充分发挥森林生态效益的前提下,进行资源的培育、保护和利用,将"生态优先"贯穿于经营管理的全过程;分析了实施"生态优先"思想存在的一些矛盾;最后指出了实施"生态优先"经营思想的实践途径包括:(1)增强全民的生态环境意识,(2)重视生态规划、合理利用森林资源,(3)建立森林生态环境预警系统,(4)合理利用市场机制与政府职能,(5)建立森林生态效益补偿基金制度。     

Visual and "phonetic" coding of movement: evidence from american sign language

Hearing subjects unfamiliar with American Sign Language and deaf native signers made triadic comparisons of movements of the hands and arms isolated from American Sign Language. Clustering and scaling of subjects' judgments revealed different psychological representations of movement form for deaf and hearing observerd. Linguistically relevant dimensions acquired modified salience for users ofa visual-gestural language. The data indicate that the modification of natural perceptual categories after language acquisition is not bound to a particular transmission modality, but rather can be a more general consequence of acquiring a formal linguistic system.     

Information and the ecology of scholars

Groups of scholars often behave in ways that are startlingly reminiscent of the behavior of groups of plants and animals in a biological ecosystem. I have tried to show that the parallel may have its basis in two fundamental considerations: (i) the similar properties of stable dissipative structures in a wide variety of contexts and (ii) the mathematical similarity of information to chemical (nutrient) free energy. A particularly intriguing problem is that of successional trends arising from the kinetic limitation of information flow through the intellectual and social structures created by scholars. The "strategy of ecosystem development" may have implications for the strategy of academic administration. In this connection, it is worth bearing in mind Marglef's dictum (6, p. 77): "Probably the hypothesis holds everywhere that the less mature ecosystem feeds the more mature structures around it."     

Evolutionary ecology of the prezygotic stage

The life cycles of sexually reproducing animals and flowering plants begin with male and female gametes and their fusion to form a zygote. Selection at this earliest stage is crucial for offspring quality and raises similar evolutionary issues, yet zoology and botany use dissimilar approaches. There are striking parallels in the role of prezygotic competition for sexual selection on males, cryptic female choice, sexual conflict, and against selfish genetic elements and genetic incompatibility. In both groups, understanding the evolution of sex-specific and reproductive traits will require an appreciation of the effects of prezygotic competition on fitness.