Abstract:The effect of traffic and railway construction on the activities of wild animals during the daytime along the Qinghai-Tibetan highway between Budongquan (3517′ N; 9316′ E) and Wudaliang (3513′ N; 9304′ E) was studied in August 2003 and August 2004. Furthermore, passageways cross the Qinghai-Tibetan railway were monitored to determine the relationship between the usage frequency of the passageways and the distance to the Qinghai-Tibetan highway and the dimension of the passageways. The results showed that the traffic during the daytime had some effects on the Tibetan antelope (Pantholops hodgsoni), Tibetan gazelle (Procapra picticaudata) and Kiang (Equus kiang) when they were crossing the road, and especially it is significant on the Tibetan antelope. At the same time, they could adapt themselves to the changes in the surroundings by learning and by adjusting their behavior. Most of their activities took place in the morning in order to avoid the effects of traffic, and they could also find and use the passageways cross the Qinghai-Tibetan railway. The dimensions of the passageways, the distance to the Qinghai-Tibetan highway, the surrounding habitat, and human activities could influence the efficiency of the passageways. Most passageways cross the Qinghai-Tibetan railway could not be effectively used by the wildlife because of the short length and low height or because of human activities in the contiguous areas of the passageways. However, the wildlife could adapt themselves to the changes in the surroundings caused by the construction of the Qinghai-Tibetan railway by learning and by adjusting their behavior.

Abstract:The effects of different traveling disturbances on the different layers of the Pinus taiwanensis community in Tianzhu Mountain National Forest Park were studied using the diversity indices of species richness index (S), Simpson index (D), Shannon-Wiener index (H) and Pielou evenness index (J). The results showed that the diversity indices of the arbor layer in low disturbance were the highest. Whereas, the diversity indices of the other layers in intermediate disturbance were the highest. The values of S, D, H, and J in low disturbance were 38, 3.0976, 0.9326, and 0.7515. The values of the indices in intermediate disturbance were 44, 3.2519, 0.9421, and 0.8594, higher than those in low disturbed forest, especially in the shrub and herb layers. In the highly disturbed forest, the diversity indices were 34, 3.0095, 0.9289, and 0.7834, lower than those in the intermediately disturbed forest. By comparing the stability of differently disturbed forests with the community dominance index (C), it was clear that the C of the intermediately disturbed forests was the lowest among the three differently disturbed forests. It is proposed that the intermediately disturbed forests can improve the species diversity, but maybe decrease the community stability.

Abstract:The species composition, biomass, abundance and species diversity of zooplankton were determined for samples collected from 12 stations in Sanmen Bay, China, in four cruises from August 2002 to May 2003. Growth of phytoplankton and grazing rates of microzooplankton were measured using the dilution technique. The spatial and temporal variation of zooplankton and its relationship with environmental factors were also analyzed. The results showed that a total of 89 species of zooplankton belonging to 67 genera and 16 groups of pelagic larvae were found in Sanmen Bay. The coastal low-saline species was the dominant ecotype in the study area, and the dominant species were Calanus sinicus, Labidocera euchaeta, Tortanus derjugini, Acartia pacifica, Pseudeuphausia sinica and Sagitta bedoti. Maximum biomass was recorded in August, followed by November and May, and the lowest biomass was recorded in February. Similarly, the highest abundance of zooplankton was observed in August, followed by May, November, and February. Grazing pressure of microzooplankton on phytoplankton in Sanmen Bay existed throughout the year, although the grazing rate of microzooplankton on phytoplankton varied with the season. Estimates for growth rate of phytoplankton ranged from 0.25 d^-1 to 0.89 d^-1, whereas grazing rate of microzooplankton ranged between 0.18 d^-1 and 0.68 d^-1 in different seasons. The growth rate of phytoplankton exceeded the grazing rate of microzooplankton in all the seasons. Grazing pressure of microzooplankton on phytoplankton ranged from 16.1% d^-1 to 49.1% d^-1, and the grazing pressure of microzooplankton on primary production of phytoplankton ranged from 58.3% d^-1 to 83.6% d^-1 in different seasons.

Abstract:Zooplankton is an important link between phytoplankton and higher consumers in the marine food chain. To investigate the harmful effects of the toxic dinoflagellate Alexandrium species on zooplankton, 4 strains of Alexandrium spp., isolated from the Chinese coast, were used to test the species' effects on the survival and feeding rates of the brine shrimp, Artemia salina. The experiment was designed to assess the response of A. salina in each stage of its life cycle: nauplii, metanauplii, and adult. Each experiment was conducted in a 500 ml treatment that was added. The toxic treatments consisted of single strains of A. minutum, A. catanella, and A. tamarense (Nanhai and Donghai strain), while non-toxic species (dinoflagellate Prorocentrum donghaiense and diatom Chaetoceros minutissimus) were used as control treatments. An additional phytoplankton treatment consisted of, a mixture of A. tamarense (Nanhai strain) and0 P. donghaiense. Alexandrium spp. species were found to have lethal effects on the brine shrimp at a density of 2000 cells/ml. All the brine shrimps died within 24-168 hours of inoculation with the 4 treatments each containing single toxic Alexandrium species. During the feeding experiment, toxic Alexandrium spp. caused a reduction in the feeding rates in all the three stages of the life cycle of A. salina, whereas this response was not obvious in the treatment involving the nontoxic species P. donghaiense. The body surface of the brine shrimp that were fed on Alexandrium species was consistently covered by a sticky floc. Mortality of A. salina was observed to increase with the occurrence of the floc. The toxicity of the paralytic shellfish poisons (PSP) produced by the Alexandrium species was not significantly correlated with the survival or the feeding rate of the brine shrimp. When A. tamarense was mixed with P. donghaiense, the lethal effect of A. tamarense decreased, as shown by an increase in the survival and the feeding rates of the brine shrimp. A. salina metanauplii were found at the life stage most sensitive to the toxic algae and hunger. In summary, toxic Alexandrium spp. were found to have lethal effects on A. salina and to restrain the brine shrimp's feeding rate. Nontoxic Prorocentrum mitigated the toxicity of Alexandrium to a certain extent. The results also imply that the sticky material on the surface of the body of the brine shrimp may have been an important lethal factor rather than the PSP toxins.

Abstract:Daya Bay is a large bay along the southern coast of China. The composition, abundance, community structure and diversity of phytoplankton in Daya Bay were investigated to assess its status in different seasons in 2002, and a total of 48 genera and 114 species of phytoplankton were identified. The cell abundance of phytoplankton varied from 5.79 10⁴ cells/m³ to 5.37 10⁶ cells/m³ with an average of 1.1410⁶ cells/m³. The largest community was Bacillariophyta containing 84 taxa, and its average abundance was 1.08 10⁶ cells/m³. Annual abundance variations show a typical one-peak cycle, with the highest peak recorded during summer and the lowest recorded during autumn. The ecotypes of phytoplankton were mostly alongshore warm-water species; however, marine warm-water species and eurytopic species during winter and autumn are more abundant than during the other seasons. The dominant species were diverse and varied with seasons. The species diversity index of phytoplankton in Daya Bay was low during summer, especially near the nuclear power station (NPS) and the aquaculture farms during summer and autumn. Community structure and cell abundance were categorized in relation to monsoon, current and anthropological activities. It is presented that the temperature and hydrodynamics in conjunction with the pattern of nutrients (DIN, DIP and N/P) availability and depletion affect the composition, abundance, community structure, community succession and diversity of phytoplankton.