会议报道:北京生物入侵国际研讨会:2004年6月6日-11日

Scientists and policy-makers are now well aware of the ecological and societal problems associated with the introduction of species by humans across natural barriers to dispersal. Some introduced species spread abundantly in their new habitats and have negative effects on existing species, both agricultural and natural. Such introduced,invasive species can alter fire, nutrient, and hydrological regimes and have large economic costs.     

Invasion history of Solenopsis invicta （Hymenoptera： Formicidae） in Fujian,China based on mitochondrial DNA and its implications in development of a control strategy

One of the most invasive species worldwide, Solenopsis invicta Buren, has been described in China since 2003. Recent studies have suggested that China populations are the result of introductions from the USA; however, detailed molecular studies need to be performed in order to understand the expansion and potential multiple introductions from other countries into China. As there were populations of red imported fire ant, S. invicta in different areas and with different methods of introduction, mitochondrial cytochrome oxidase Ⅰ gene was used as a marker from 12 populations in four cities in Fujian Province, China, to determine the relationship of invasion among these populations. The three most common haplotypes previously describe in invasive populations of S. invicta： H5, H22 and H36, were found in Fujian. However, frequencies in each city were different. For instance, three populations from Longyan city which invaded with waste plastics, shared haplotype H5. Populations from Xiamen city and Jinjiang city which dispersed with nursery stock, sward and scrap leather, shared haplotype H22. The population from Nanyan village of Xinluo district, Longyan city, bore haplotype H36. Mitochondrial data reveals that the invasion history of S. invicta in Fujian Province is complex, including multiple invasions probably from other provinces within China. Security measures to prevent S. invicta spreading within China are as important as from overseas.     

Biogeographic diversification in Nolana （Solanaceae）, a ubiquitous member of the Atacama and Peruvian Deserts along the western coast of South America

The present paper reconstructs the biogeographic diversification for Nolana L.f. （Solanaceae）, a genus of 89 endemic species largely restricted to fog-dependent desert lomas formations of coastal Peru and Chile. Previous efforts have reconstructed a phylogenetic estimate for Nolana using a combination of molecular markers. Herein, we expand on those results to examine hypotheses of biogeographic origins and diversification patterns. Nolana occupies habitats within a continuous coastal desert and forms a terrestrial archipelago of discrete ＂islands＂ unique in size, topography, and species composition. Each locality contains at least one Nolana species and many contain multiple species in sympatry. The genus has a Chilean origin, with the basal clades confined to Chile with wide geographic and ecological distributions. Peru contains two strongly supported clades, suggesting two introductions with subsequent radiation. A Chilean clade of shrubby, small-flowered species appears to have had its origins from the same ancestors of the second line that radiated in Peru and northern Chile. Nolana galapagensis is endemic to the Islas Galapagos, with origins traced to Peruvian taxa with a divergence time of 0.35 mya. Rates of diversification over the past 4.02 mya in Nolana, in one of the driest habitats on Earth, suggest rapid adaptive radiation in several clades. Success in Nolana may be attributed to characters that confer a competitive advantage in unpredictable and water-dependent environments, such as succulent leaf anatomy and ecophysiology, and the reproductive mericarp unique to Nolana. The processes affecting or shaping the biota of western South America are discussed.     

Patterns of phylogenetic relatedness of non-native plants across the introduction-naturalization-invasion continuum in ChinaOA

Human activities have caused the exchange of species among different parts of the world.When introduced species become naturalized and invasive,they may cause great negative impacts on the environment and human societies,and pose significant threats to biodiversity and ecosystem structure.Knowledge on phylogenetic relatedness between native and non-native species and among non-native species at different stages of species invasion may help for better understanding the drivers of species invasion...     

A New Species of the Genus Cecidomyia from China(Diptera: Cecidomyiidae)

Twelve species of the genus Cecidomyia have been reported from North America andEurasia. They are known as pine resin midges inhabiting mainly the pines, also spruce andfir. The larvae fecd on pitch and cause extensive primary damage to the hosts. The new res-in midge species here dealt with is known so far only from Jiangbian Forestry Bureau dis-trict, Yunnan.     

Differences in Incubation Length and Hatchling Morphology among Five Species of Oviparous Phrynocephalus Lizards （Agamidae） from China

We incubated eggs of five Phrynocephalus species （P. albolineatus, P. axillaries, P. grumgrzimailoi, P. helioscopus and P. przewalskii） at three constant temperatures （24℃, 28℃ and 32℃） to examine differences in incubation length and hatchling morphology among species and among temperature treatments. We combined data from this study with those reported previously for P. frontalis and P. versicolor to examine whether embryonic stage at laying is a causal factor for interspecific variation in incubation length, and whether the phylogenetic relationship inferred from hatchling morphology is consistent with the relationship based on mitochondrial DNA data. Mean values for incubation length differed among the five species studied herein and, in all these five species, incubation length decreased at a decreasing rate as temperature increased. In none of the five species did hatchling size （snout-vent length and body mass） and other morphological variables differ among the three temperature treatments. The seven oviparous Phrynocephalus lizards found in China differ from each other in hatchling morphology, and embryonic stage at laying is a causal factor of inter- and intra-specific variation in incubation length. The phylogenetic relationship inferred from hatchling morphology is not always consistent with the currently known relationship based on mitochondrial DNA data. Data from this study and those reported previously allow the conclusion that any Phrynocephalus species may have its unique position along the axis defined by hatchling morphology.