Dianmo Li

Study on biogeographical divisions of China

On the basis of comprehensive natural factors (including altitude, landform, climate, vegetation, water system, farm belt, and so on), we first divide Chinas territory into 124 basic units by applying GIS techniques. Then 171 species of mammals and 509 of plants are selected for analysis on the basis of taxa with many representative species, wide distributions across China or thought to reveal biogeographic divisions in less well known parts of the country. We collected distribution data of these species through the China Species Information System, and utilized the GIS technique to identify in which of the 124 units each species has been recorded. The resulting data matrix was then arranged into dendrograms, aggregating the units at various levels on the basis of the mammal and plant distributions by application of similarity cluster analysis using both the Sørensen comparability index formula, and the Ward method to calculate correlation matrices. Finally, we summarize the different distribution characteristics of the aggregated units and their reasons of the two categories from these cluster dendrograms, and reach some important conclusions on the biogeographical regionalization of China. This research adopts a study method of starting from minimal basic units and then aggregating up to higher-level divisions, which is a new methodological attempt in the biogeographic division research field within China. By this method, the division boundaries can be determined by the cluster results of species distribution comparability rather than the limited species and ecology knowledge of an individual researcher as has been done in the past. This makes the resulting classification more objective and broader based. This method is also applicable to other biological taxa.

Habitat evaluation for crested ibis: A GIS-based approach

We evaluated habitat quality for crested ibis (Nipponia nippon) using a geographic information system (GIS). First, we digitized the topography map, vegetation map, river map, road map and villages/towns map by ArcInfo, and gave each map layer a suitability index based on our perceptions of the needs of crested ibis. Second, we overlayed these maps to obtain an integrated map of habitat quality. Finally, we compared the calculated habitat quality with the actual distribution of crested ibis. We found that the birds were almost always located at the site of high quality (habitat suitability index [HSI]u2009>u20090.6), which indicated that the factors we selected were important for crested ibis. We also found that crested ibis were never located at some sites of high quality, thus, we assume that other factors not considered in this study limit the distribution of crested ibis. Regression analysis indicated that crested ibis preferred lower elevation habitats and tolerated higher levels of human disturbance in recent years than previously reported. These results reflected a 20-year protection program for this species.

A possible relationship between outbreaks of the oriental migratory locust (Locusta migratoria manilensis Meyen) in China and the El Niño episodes

We investigated the statistical relationship between outbreaks of the oriental migratory locust (Locusta migratoria manilensis Meyen) in the Huang Ho and Huai Ho regions of China and El Niño episodes during 1905–1959, and discussed how El Niño affects locust outbreaks. The outbreaks of the locust mostly occurred 1–2 years after the El Niño episodes. El Niño was suggested to affect the locust outbreaks by changing the precipitation and air temperature in Northern China.

Effects of Bt‐toxin Cry1Ac on Propylaea japonica Thunberg (Col., Coccinellidae) by feeding on Bt‐treated Bt‐resistant Helicoverpa armigera (Hübner) (Lep., Noctuidae) larvae

Abstract:u2002 Propylaea japonica is an important predatory insect of common cotton pests. To assess the ecological effects of transgenic Bt cotton, expressing Cry1Ac toxin, on this predator, we examined the life history parameters of P. japonica for two generations by feeding them with Bt‐resistant Helicoverpa armigera. After ingesting Bt‐treated Bt‐resistant H. armigera larvae in the third and fourth instar, the body mass and body length of adult P. japonica decreased, a combined effect of poor prey quality and Cry1Ac Bt‐toxin may account for these effects. However, larval survivorship and development in these two instars, pupal mortality, fecundity and adult longevity of P. japonica were not affected in both the generations. These results suggest that ingesting Bt‐toxin Cry1Ac‐treated pests in advanced larval stage might have no significant effect on the fitness of predator P. japonica.

Nest site use by crested ibis: dependence of a multifactor model on spatial scale

The crested ibis (Nipponia nippon), a species at the brink of extinction in 1981, remain restricted to a small (25xa0km radius) area of temperate forests in central China. To improve the chances of successful reintroduction into new areas we developed a multifactor logistic regression model of habitat association at multiple scales. Using habitat variables, i.e. vegetation, human impact, elevation, and wetland, we compared occupied and unoccupied sites at grain sizes ranging from 1 to 6400xa0ha. The goodness-of-fit of the habitat suitability model depended on grain size, with the best fit (most information) at a grain size of 2xa0ha. Semivariograms showed the habitat variables at control sites have a gradient pattern, yet the crested ibis had their specific habitat preferences, and only selected a narrow range from the available gradient. Our results indicated that spatial scale needs to be considered in developing habitat models for applications such as conservation planning.

Why the crested ibis declined in the middle twentieth century

The crested ibis (Nipponia nippon) had declined severely from a common species to only two pairs in last century. To analyze the declining process, we established a GIS database with historical occurrences of the crested ibis based on published literatures, and layers of environmental factors such as elevation, wetland, and human activities. We compared the environmental factors at the occurrence sites in different periods to quantify the changes of habitat use across time. To address the spatial deviation of the occurrences and check the effect of measuring scale on habitat use, we calculated the environmental factors in a serial measuring scales from 1 to 161xa0×xa0161xa0km2. Our results indicated that the crested ibis traditionally lives in habitat with higher wetland density and higher human impact, then it gradually moved to areas with higher elevation and lower human impact in last century. In 1980–2000 the crested ibis stayed at a very high elevation, lower wetland density and lower human impact as possible consequences of human activities such as using fertilizer and pesticide, drying the over wintering rice paddies, and direct hunting. Our quantitative analysis of the habitat use matched well the previous published statements (which have no numerical evidences) on the declination of the crested ibis. We suggest to reestablish the habitat with traditional farming practice that the bird has adapted as a major solution for applications such as conservation planning and reintroduction.

Vulnerability of 208 endemic or endangered species in China to the effects of climate change

We assessed the vulnerability of 208 endemic or endangered species in China to the effects of climate change, as a part of the project “Research on China’s National Biodiversity and Climate Change Strategy and Action Plans”. Based on the China Species Information System, we selected comprehensive species as analysis targets, covering taxa including mammals, birds, reptiles, amphibians and plants. We applied nine species distribution models in BIOMOD (a package of R software) to estimate the current (1991–2010) ranges and predicted future (2081–2100) ranges of these species, using six climate variables based on Regional Climate Model version 3 (RegCM3) and A1B emission scenario. The model results showed that different taxa might show diverse potential range shifts over time. The range sizes of half of the species (104 species) would decrease, and those of another half would increase. We predicted that the future remaining ranges (intersection of current and future ranges/current ranges) of 135 species would be less than 50xa0% of their current range sizes. Species that are both endemic and critically endangered would lose more of their range than others. In summary, the most vulnerable species are currently found on the Qinghai-Tibetan Plateau, in the Hengduan Mountain Range, and southern China. Future action plans dealing with climate change in China should be prepared with consideration for vulnerable species and their habitats.

Current state and the future of the crested ibis (Nipponia nippon): A case study by population viability analysis

There is only one population of the crested ibis (Nipponia nippon) surviving in the wild, which has not exceeded 40 individuals since it was rediscovered in 1981. We used detailed data of the annual population size and natality collected by the Crested Ibis Conservation and Observation Station (CICOS) over the past 17u2009years. We were able to obtain a more accurate census of age structure and mortality as all of the fledglings have been identified by leg bands in 1987. Consequently, we analyzed the current state of the crested ibis and predicted its future using Population Viability Analysis (PVA) with the help of the computer simulation model VORTEX (Version 7.2). The results indicated that the extinction probability of the crested ibis was 19.7% in 100u2009years. Sensitivity analysis showed that the extinction probabilities were sensitive to catastrophes and environmental variation, and the long-term existence of the population was dependent on the carrying capacity of the habitat and inbreeding depression. Conservation efforts are critical for the survival of the crested ibis. The prior conservation project involves controlling hunting and predation, as well as improving the life level of these few remnant creatures.

Using multi-temporal Landsat ETM+ data to monitor the plague of oriental migratory locust

This paper aims to evaluate the effectiveness of using Landsat ETM+ data to identify the extent and severity of locust damage. Two cloud‐free Landsat ETM+ images of the study area, taken before and after peak locust plague, were compared to determine the extent and severity of the 2002 locust plague according to the decrease of the Normalized Difference Vegetation Index (NDVI) derived from the two images. The results showed that the locust plague could be classified into heavy, moderate and light damage degrees based on the NDVI value decrease calculated by each pixel, which further evaluated its accuracy by extensive ground survey data. Locust plague can be identified with 98% and 92% accuracy for determining geographic extent and severity respectively using Landsat ETM+ data.

Biology of Campoletis chlorideae (Uchida) (Hym., Ichneumonidae) developing in Bt-treated, Bt-resistant Helicoverpa armigera (Hübner) (Lep., Noctuidae) larvae

Abstract:u2002 Life history parameters in two generations of endoparasitoid Campoletis chlorideae (Uchida) were examined using Bacillus thuringiensis (Bt)‐resistant Helicoverpa armigera (Hübner) larvae feeding on B. thuringiensis toxin Cry1Ac. In the laboratory, Bt toxin was fed to Bt‐resistant host larvae continuously in case of Bt treatment and only before or after the host larvae were parasitized in Bt–P and P–Bt treatments, respectively. C. chlorideae pupae developed faster in Bt treatment than non‐Bt treatment. The shortened pupal stage duration was mainly because of the feeding of host larvae on Bt‐diet before being parasitized. Body length of adult male C. chlorideae developed inside Bt‐treated Bt‐resistant (Bt–Bt) H. armigera larvae significantly decreased, especially in host larvae feeding on Bt‐diet after being parasitized. However, survival, pupal mortality and adult longevity of C. chlorideae were almost unaffected in Bt‐resistant H. armigera larvae feeding on Bt‐toxin. Furthermore, Bt‐treated host larvae had the same effect on the F1 progeny of C. chlorideae as the previous generation, and there was no significant difference between generations. This experiment suggests that there is very limited effect on the life history parameters in two generations of C. chlorideae parasitizing Bt–Bt H. armigera larvae. But both generations of C. chlorideae are affected when Bt‐resistant H. armigera larvae fed on Bt toxin for different durations.