《神乌赋》评析

《神乌赋》以鸟为题材,有着深厚的文化渊源和文化积淀;隐喻社会矛盾,与古代民歌,特别是汉乐府民歌有很多相似之处;作为俗赋,其叙事性、拟人化手法和朴实的风格表现出了与文人赋截然不同的、鲜明的艺术特征。《神乌赋》的出土,对研究汉赋及汉代文学的发展,有着重大的价值。     

Occurrence of breeding bird species in urban parks: Effects of park structure and broad-scale variables

Occurrences of breeding bird species in 54 urban parks were investigated in the city of Oulu in northern Finland. Park area, human activity, habitat, and landscape structure within a 9-ha square surrounding the study park were related to the bird species richness and occurrence of individual bird species. A total of 22 species was observed. The area of the park explained 39% of the variance of species richness. Seven species (wheatear [Oenanthe oenanthe], common rosefinch [Carpodacus erythrinus], garden warbler [Sylvia borin], lesser whitethroat [Sylvia curruca], linnet [Acanthis cannabina], redpoll [Carduelis flammea], and yellowhammer [Emberiza citrinella]) were not detected in parks of >0.75 ha. Species with lower area demands occurred closer to the town center than species with greater area requirements. Ground-nesting species were poor colonizers of urban parks, whereas high numbers of nest boxes in urban parks attracted many cavity-nesting species. The willow warbler (Phylloscopus trochilus) and the magpie (Pica pica) bred more often in unmanaged than in managed parks, probably because of the greater vegetation cover in unmanaged parks. Park structure variables were entered into models for 7 of the 12 most common bird species, whereas broad scale variables were entered into models for 6 of the 12 species. The number of adjacent buildings had a negative affect on three bird species (the willow warbler, hooded crow [Corvus corone cornix], and spotted flycatcher [Muscicapa striata]). The occurrence of breeding species in urban parks depends on the size of the park, park structure, and landscape structure outside the park.     

汉魏赋中的鸟意象

~~汉魏赋中的鸟意象@侯立兵$湖南文理学院中文系!湖南常德415000~~~~~~     

生命的感悟与寄托--析陈子昂《感遇》诗中白云、白日、飞鸟的意象

陈子昂的《感遇》诗继承了历代诗歌中优秀的意象并体现了时代的新气息,其中的白云、白日、飞鸟词语使用频率颇高,蕴含了诗人渴望为世所用的内心感触,诗人用时代的笔墨蘸染着真性情,有力地开拓了一代诗风。     

朝阳地区鸟类化石的发现与研究

鸟类是从恐龙演化而来,还是从恐龙的先祖那里演化而来,是过去40年来在古脊椎动物领域最有争议的问题。以中华龙鸟为代表的一大批珍稀动物化石在朝阳地区相继发现,引发了许多有关鸟类起源和早期演化的研究课题。描述了发现于朝阳地区具有代表性的鸟类化石,并阐述了鸟类化石发现的意义及由此引发的学术观点。     

Patterns of human disturbance and response by small mammals and birds in chaparral near urban development

We report on the extent of disturbance (including habitat alteration and road and trail proliferation) in chaparral near urban development and analyze the effects of disturbance on small mammal and resident bird species. Disturbance patterns were evaluated in a 6700 ha study area in southern California: effects on mammals and birds were investigated by analyzing relationships between vegetation structure and animal species richness and abundance. Disturbance was prevalent throughout the study area and included extensive human-altered habitat (from past human activities such as vegetation clearing, human-caused fires, refuse dumping, and vegetation trampling) and 157 km of roads and trails. A nonsignificant trend was found between human-altered habitat and proximity to development, but human-altered habitat was significantly associated with roadway proximity. Trails were also more frequent near urban development and roads. Small mammals responded strongly to disturbance-related vegetation changes, while birds showed little or no response. Mammals endemic to chaparral vegetation were less diverse and abundant in disturbed sites, whereas disturbance-associated species increased in abundance. Close proximity of urban development to natural areas resulted in alteration of natural habitat and proliferation of roads and trails. Variation in life history traits between birds and mammals may affect response to disturbance and influence persistence if disturbance continues. Conservation efforts must recognize the potential for habitat damage and associated declines in native animal species caused by disturbance near urbanization and implement strategies to reduce these threats.     

Land-use planning to conserve habitat for area-sensitive forest birds

Models predicting the occurrence of area-sensitive bird species in forests were developed from bird survey data from 499 forests in Prince George's County, Maryland. The predicted probabilities of occurrence for species were integrated with forest cover data for the County in a Geographic Information System (GIS). This information was used in combination with local zoning and forest conservation requirements to develop a preliminary forest conservation plan for the watershed of the Western Branch of the Patuxent River. We identify forests patches most likely to support breeding populations of area-sensitive birds, and use the GIS to devise ways to consolidate and link them. Forests that do not contribute significantly to the integrity of these priority forests are designated as sites in which development could occur. The resulting conservation plan will maintain and enhance breeding habitat for area-sensitive forest birds, while still allowing for additional development as human populations increase.     

The natural South Florida system II: Predrainage ecology

The goal of the South Florida restoration process is to reestablish a sustainable ecological system that approximates the predrainage system (i.e., the system that existed before canals and water control structures were built). A critical step in the restoration process is to describe the predrainage system with sufficient detail to capture the essential landscape features (e.g., space, connectivity, patterns) that gave the region its defining character and supported its natural abundance and diversity of plants and wildlife.A previous attempt at reconstruction of predrainage (circa 1870) vegetation patterns covered only the Everglades (Davis et al., 1994) but introduced a concept of landscape mosaics that should be extended to South Florida. We propose 16 landscape units that include freshwater landscapes, upland landscapes, coastal wetlands, and estuaries (particularly Florida and Biscayne Bays), the Florida Keys and Reef Tract, and the Inner Southwest Florida Shelf.The predrainage area, because of its enormous size, supported a landscape heterogeneity that was advantageous to animals with several distinct habitat-related life strategies. Five species have been selected to illustrate different dependencies on landscape patterns in predrainage South Florida: wood stork (Mycteria americana), American alligator (Alligator mississippiensis), snail kite (Rostrhamus sociabilis), Cape Sable seaside sparrow (Ammodramus maritimus mirabilis), and pink shrimp (Penaeus duorarum). As individuals or as populations, these animals operated across several spatial and temporal scales. The predrainage system's large spatial extent and complex hydropatterns allowed wood storks and other animals with large feeding ranges to take advantage of the strongly seasonal rainfall pattern, while at the same time providing a refuge somewhere in the system for survival of all other species. Landscape heterogeneity and large spatial extent promoted the region's natural wildlife abundance and species diversity.