The B biotype of Bemisia tabaci, sometimes called a “super bug”, has been one of this species complex’s most harmful biotypes because of the tremendous damage it inflicts worldwide. Recently, competitive displacement of pre-existent biotypes and other herbivores by the B. tabaci B biotype has been observed in many regions worldwide. Based on literature review, the mechanisms responsible for competitive replacement by B. tabaci may include exploitation or interference competition, which involve niche competition, differential abilities in resource acquisition, asymmetric mating interactions, heat shock adaptation, pesticide susceptibility, and interactions between B. tabaci B biotype, host plants, and viruses. Moreover, the B biotype likely has unique endosymbionts, which may be important in enhancing its competitive ability. We also discuss related mechanisms involved with serious damage caused by the B. tabaci Q biotype.

Arbuscular mycorrhizal (AM) fungi are obligate symbiotic endophytes which have not been cultured in vitro. The life cycle of AM fungi can be completed only when the mycorrhiza forms between the fungi and plant roots. There are more than 200 genetically-diverse species of AM fungi belonging to Glomeromycota in the Kingdom Fungi. It is well documented that surprisingly high genetic variability exists between and within species, and even in a single spore of AM fungi. We summarize recent advances in the study of AM fungal diversity, discuss some related problems, and introduce present and future research trends.

In the context of increasing anthropogenic activities, nutrient enrichment and physical disturbances are among the most important environmental factors influencing biological invasions. On the other hand, clonal growth and vegetative propagation are considered important life history traits promoting the invasiveness of plants in high-resource and disturbed habitats. Alternanthera philoxeroides, endemic to South America, is an amphibious clonal weed invading areas worldwide. It is widely distributed in warm-temperate and subtropical regions, and tends to invade nutrient-rich and disturbed habitats such as riparian zones, wetlands, and arable areas. Throughout its introduced range, A. philoxeroides rarely produces viable seeds and reproduces mainly by vegetative propagation via storage roots and stems. Therefore, formation of storage roots, sprouting of root buds, and growth of new ramets are crucial characteristics in the life history of A. philoxeroides. We conducted three container experiments to examine the responses of vegetative propagation characteristics of A. philoxeroides to two factors—nutrient addition and physical disturbance (two types of physical disturbance: fragmentation and burial of storage roots). Nutrient addition increased total biomass and mean length of storage roots 1.5-fold, and biomass allocation to storage roots by 15% (i.e., vegetative reproductive allocation). Number of root buds increased by approximately 15 sprouts per g (dry mass) of storage root. Burial depth had no effect on number of sprouts per root fragment. Neither storage root size nor burial depth affected main stem length or mean relative growth rate of ramets. Our results suggest that adaptation of vegetative propagation characteristics to nutrient enrichment and physical disturbances may enable localA. philoxeroides populations to grow rapidly, and contribute greatly to the persistence of metapopulations at the watershed scale.

Due to its rapid growth,Sonneratia caseolaris, a mangrove species indigenous to Hainan, was introduced to Shenzhen Bay, Guangdong for afforestation purpose during the early 1990s. The seedling emergence, early growth and dispersal pattern of S. caseolaris and their responses to environmental factors have not been well studied in the new habitat. In this study, we evaluated the density, height and coverage of S. caseolaris seedlings underneath the canopies of various mangrove forests (including both natural Kandelia candel and Avicennia marina communities and introduced S. caseolariscommunities) and on the mudflats without canopy, in Futian Mangroves Natural Reserve of Shenzhen Bay from September 2006 to September 2007. Line intercept and square intercept methods were used in the survey. Tidal elevation, light intensity, community types and the distance between the sample squares and the nearest adult S. caseolaris were also recorded. The mean densities of S. caseolaris seedlings under the canopies of both the introduced and natural mangrove forests decreased from September 2006 (24.7 seedlings per m²and 19.7 seedlings per m², respectively) to September 2007 (no seedlings survived). No significant differences were found in the seedling density, height or coverage of S. caseolaris among different mangrove communities. However, the density, height and coverage of S. caseolaris seedlings were significantly higher on the mudflats without canopy than under the mangrove canopies, indicating that higher light intensity in on the mudflats without canopy promoted the dispersal and vertical growth of S. caseolaris seedlings. Although the optimal tidal elevation for S. caseolaris seedlings in Shenzhen Bay was between 1.40 m and 1.60 m, an area that falls within the mid-to-high intertidal zones, seedling density and tidal elevation were weakly correlated. The seedling density under the native mangrove canopies was negatively related to dispersal distance. However seedling density were positively correlated with light intensity(P<0.05), and the correlation coefficients for the introducedS. caseolaris forest increased through time with successive surveys. In contrast, there was no significant correlation founded between seedling density and light intensity under native mangrove canopies. We concluded that distance to mother tree was the most important factor determining S. caseolaris seedling density under native mangrove canopies, whereas the light intensity was the most important environmental factor for controlling seedling dispersal pattern under the canopy of the introduced S. caseolaris forest.

Epiphytes are important components in tropical and subtropical forest ecosystems, and are well-known for their sensitivity to environmental changes. To understand epiphyte’s response to forest fragmentation and edge effects, we established four plots at the edges of a montane moist evergreen broad-leaved forest in the Ailao Mountains of Yunnan. Within each plot, we established four transects at 10, 20, 40, and 80 m from forest edge to study the species composition, biomass, and life form of epiphytes on host trunks 0-2 m above the ground. Distance to edge influenced biomass of epiphytes (P < 0.001) and coverage of epiphytic bryophytes ( P < 0.001). Epiphytic bryophytes were more sensitive to edge effects than epiphytic ferns. The intensity of edge effects were life-form specific, and turf ( P = 0.014) and weft forms (P = 0.030) both showed a pronounced response. Based on the distributional traits of epiphytes in all plots, we concluded that both the biomass of epiphytes and coverage of epiphytic bryophytes are biological indicators of forest edges. Furthermore,Ditrichum pallidum, Wijkia hornschuchii andHerbertus giraldianus are capable of indicating edge habitats, while the conservation status of Thuidium philibertii,T. cymbifolium, Claopodium pellucinerve, Pseudotrismegistia undulata and Trachypus bicolor deserve further attention because they are excluded from forest edges.

Categories and criteria established by the IUCN for globally endangered species have been used by many countries for conservation decision making. Based on geographical distributions and the Red List of China and Red List of Japan, we compared the current status of threatened plants and the floristic composition of the two countries. We highlight our results as follows: (1) the proportion of wild seed plants found on the Red List to total seed plant species was lower in China than in Japan, but the degree of threat for gymnosperms was higher in China than in Japan; (2) several hydrophyte families were not listed on the Red List of China, but have been severely threatened in Japan; (3) the number of cosmopolitan genera endangered in China was fewer than in Japan; and (4) among species threatened in both China and Japan, there was a large proportion of common species, sister species, and closely related species. Finally, we suggest that: (1) a comprehensive evaluation of the status of hydrophytes in China; (2) an increased effort to study species common to China and Japan; and (3) following the example of Japan, a thorough investigation should be conducted at the plant community level in China to complement the Red List.

Abstract: Medicago lupulina is an annual or short-perennial and widespread herbaceous plant. It is generally considered a selfing species with a strong self-compatibility system, but a shift in mating system towards outcrossing or mix-mating has been reported. To estimate genetic variation, gene flow, mating system and genetic background of M. lupulina, we characterized 354 individuals from 17 wild populations from northern and central China using nine EST-SSRs markers. We found that: (1) EST-SSRs markers had a high percentage of polymorphic loci (PPL = 71.9%) and 4-11 alleles per loci. The Xinjiang-Nalati population had the highest level of genetic diversity (H_E= 0.388), whereas the Shaanxi-Xi’an population had the lowest (H_E= 0.042). Selfing rate was 93.8 %. (2) Genetic differentiation was high among populations (F_ST= 0.528; R_ST= 0.499). Of the total genetic variation, 59.02% was found among populations. (3) Mantel test revealed that genetic distance and geographic distance were positively correlated (r = 0.4141, P≤ 0.0003). Neighbor- joining trees based on Nei’s genetic distance (D_a) showed that neighboring populations clustered into the same clade, which was consistent with results of Mantel test. Our results indicated that the genetic structure of M. lupulina populations have been strongly affected by dispersal patterns and a strategy of inbreeding.

Acacia pennata is an economically important plant that is used for timber and food by the local people in Xishuangbanna, Yunnan. The objectives of this study were to evaluate the genetic diversity and genetic differentiation of natural populations and present a scientific framework for the conservation and utilization of A. pennata. We estimated the genetic diversity and genetic structure of seven natural populations in Xishuangbanna using SSR techniques. A relatively high level of genetic diversity was detected in A. pennata using six polymorphic microsatellite loci. Based on six primers, 23 alleles were detected. Average (N_a) and effective (N_e) number of alleles were 3.381 and 2.460, respectively. The mean expected heterozygosity (H_e) was 0.573 and Nei’s diversity index (h) was 0.567. The highest genetic diversity was found in Jinghong population, while the lowest was found in Manla population. The majority of genetic variation occurred within populations and could have resulted from low genetic differentiation (F_ST = 0.113). Acacia pennata is a perennial species with a wide distribution; these characteristics could account for the relatively high genetic diversity we observed. Furthermore, this species has an outcrossing breeding system and its seeds are widely dispersed, a situation amenable to high genetic diversity and low levels of genetic differentiation among populations. Therefore, we should focus on sampling more individuals from populations with higher genetic diversity and sampling different populations forex-situ conservation of A. pennata.

The movements of four species of breeding waterbirds were studied using color marking, radio-tracking, and satellite-tracking at Qinghai Lake between April and September, 2006. Forty five bar-headed geese (Anser indicus) were captured with foot traps, including six individuals tagged with radio transmitters in April and another six birds with satellite transmitters in July. A total of 104 brown-headed gulls (Larus brunnicephalus) were captured with hand nets, and six of these were radio-tagged in April. Fifty one great black-headed gulls (L. ichthyaetus) were captured with foot traps, including two birds that were radio-tagged in April. Seventy five great cormorants (Phalacrocorax carbo) were captured using the spotlight method, including six birds radio-tagged in May and June, and four individuals tagged with satellite transmitters in August. Data showed three distinct movement routes for the bar-headed goose, one for the brown-headed gull, four for the great black-headed gull, and two for the great cormorant. Furthermore, one of these routes was shared by all four waterbird species—from Luci Island and Egg Island to Quanwan along the shore near the Buhahekou and Tiebuqiahekou. These areas are also important as foraging and resting sites for many other waterbird species during migration periods.

Fuxian Lake is a representative deep plateau lake located in Yunnan Province, China. As human activities have increased since the 1980s, nutrients in the lake have been gradually rising, thereby changing the lake ecosystem. To describe the lake’s macrozoobenthic community and its response to ecological changes, we surveyed the macrozoobenthic community in Fuxian Lake from June to July in 2005. Twenty seven macrozoobenthic species belonging to 19 genera were collected in 110 sampling sites of 18 sections, and the community’s frequency of occurrence, average density, and average biomass were 97.3%, 855 ind./m², and 58.01 g/m², respectively. Mollusca was the dominant taxa in the lake (up to 50.3% of total density), followed by Chironomidae (32.3%), and Oligochaeta (17.4%). Procladius choreus, Alocinma longicornis and Bellamya quadrata were dominant species, accounting for 51.4% of total density. Oligochaeta and Chironomidae were distributed throughout the lake, while Mollusca were mainly found in the near-shore region. All dominant species showed an aggregated distributional pattern. Average macrobenthic biomass was significantly higher in the near-shore region than in the open-water region (P< 0.01), but average density did not differ between the two regions (P> 0.05). There were no differences in average density (P> 0.05) or biomass (P> 0.05) between the southern and northern portion of the lake. Correlation analyses indicated that total organic carbon in the sediment and dissolved oxygen were the key physical-chemical factors influencing macrozoobenthic density, while dissolved oxygen was the key factor influencing macrozoobenthic biomass. Macrozoobenthic diversity measured using Pielou, Margalef, Simpson, Shannon-Wiener, and modified Shannon-Wiener indices were 0.74, 2.88, 0.87, 2.40, and 20.84, respectively. Macrozoobenthic diversity was higher in the near-shore than in the open-water region, likely resulting from various submerged macrophytes in the near-shore region, which increased habitat heterogeneity. Compared to a 1980 survey, macrozoobenthic diversity in Fuxian Lake was higher in 2005, likely a result of increased nutrient levels and enlarged distribution of submerged macrophytes.

We studied patterns of distribution and relationships among distributional areas of Tetrigidae insects in China using parsimony analysis of endemism (PAE). We constructed a matrix based on distribution data for Chinese Tetrigidae insects and an area cladogram using northeastern China area as an outgroup. Exhaustive searches were conducted under the maximum parsimony criterion. Cluster analysis divided eight biogeographic areas into four groups; group 1 was composed of northeast China, group 2 was composed of Mongolia-Xinjiang, group 3 was composed of central, eastern, and northern China, and group 4 was composed of southern and southwestern China and Qinghai-Xizang. The area cladogram suggested that northeastern China and Mongolia-Xinjiang formed earlier than others. This phenomenon is likely related to Pleistocene glacier movements. In general, Tetrigidae insect diversity was higher in southern China than northern China. We speculate that this pattern can be partially explained by the Pleistocene forest refuge theory and eco-environmental deterioration.

We collected data on breeding birds in Anhui Province, and predicted and mapped their ranges using GIS techniques. We divided the study area into 425 grids which were used as operative geographic units to analyze breeding bird distributional patterns and hotspot. Faunistic composition analysis showed that geographic units in Anhui Province could be divided into two groups along a boundary from northern Dabie Mountain to Chaohu Lake. Indomalayan species accounted for 60% of the total species in all geographic unit groups, with an increase in the group’s prevalence from north to south. Ecological distribution analysis showed that bird distribution units could be divided into two groups which were consistent with division by climatic zones. When divided into seven groups, clusters were closely related to the environmental features such as terrain and landform. The hotspot analysis showed that richness of total breeding birds, breeding birds in the “List of Wildlife Under Special State Protection” of China, and breeding birds listed in CITES appendices I and II were all higher in southern Anhui Province. Therefore, we suggest that areas in southern Anhui Province should be targeted for special protection for bird diversity conservation.