Font Size: a A A

Analysis Of Dendrolimus Tabulaeformis Occurrence With The Stand Parameters Of Pinus Tabulaeformis And Prediction Under Climate Scenarios

Posted on:2016-11-12Degree:MasterType:Thesis
Country:ChinaCandidate:X G SongFull Text:PDF
GTID:2283330470461349Subject:Forest Protection
Abstract/Summary:PDF Full Text Request
Dendrolimus tabulaeformis Tsai et Liu is the most serious defoliator of native Chinese pine, Pinus tabulaeformis, in north China. In 3 years research from 2013-2015, 13 permanent sample plots and 8 temporary sample plots were tested according the host distribution and pest damage for analysis the relationship of the pest outbreak and environmental factors. Carbon, nitrogen and water contents level in soil and in needles of pine, together with the volatiles of needles in different time of a year were also analyzed. Based on the pest life history records in north China, 73 environmental factors were derived, and 12 environmental factors that most contact to occurrence of pine moth were screening out by canonical correlation analysis and PCA(principal component analysis). Then, based on the selected 12 environmental factors and records occurrence of the pest in 2002-2014, the disaster situation of pine moth in the current climate conditions were fine simulated by MaxEnt. Trend of outbreaks of pine moth in the future climate scenarios were also predicted. The results of research as follows:1. The six main terpene volatiles of needle of host pine have different content levels in different development stage, different damage levels of the pest. The content of(r)-(+)-α-pinene and camphene were significant different between the larval stage and adult stage. The more serious damage of pine moth, the higher contens of(s)-(-)-β-pinene,(r)-(+)-α-pinene and Limonene. And the content of Myrcene, Limonene, β-caryophyllene were much higher in drought conditions.2. Forest stand parameters(carbon, nitrogen and water contents in soil and in needles of pine) are changing relate to periods of outbreaks of pine moth. Bound water in soil and nitrogen in needles of pine are different in stages of life cycle of pine moth. Water in needle of pine shows increasing trend, when occurrence of pine moth aggravated.3. There are correlation between the main six kinds of volatiles of pine and forest parameters, but with different trend. The significant positive correlation is found between(r)-(+)-α-pinene and(s)-(-)-β-pinene and soil parameters. However, Camphene showed a negative correlation with soil parameters.4. Combining the feature in different stages of the life cycle of pine moth, 73 environmental factors were derivatived, including temperature, wind speed and relative humidity. The most important 12 factors are as follows, the annual average temperature, theⅠperiod average temperature, the Ⅱ period average temperature, the Ⅳ period average temperature, the annual average wind speed, theⅠperiod average wind speed, the annual average relative humidity, the September average relative humidity, the Ⅱ period average relative humidity, the Ⅲ period average relative humidity, the Ⅱ period average highest temperature and the September highest temperature.5. There was a good result for simulation and forecasting to outbreaks of pine moth by MaxEnt with the actual occurrence data. The future forecasting result showed that different climate scenarios can effect the occurrence trend of pine moth. The occurrence of pine moth more serious under RCP2.6、RCP6.0 and RCP8.5 climate scenarios. The high risk area of occurrence concentrated around Wutai mountain in Shanxi and Chengde in Hebei, etc. There are significant differences between GFDL-ESM2 M mode and other modes.6. The life cycle of pine moth and environmental factors dynamic change can be used to screen the key environmental factors, there were relevant to the occurrence of pine moth. The prediction of occurrence trend under climate scenarios by the key environmental factors. The prediction can provide important basis for establishment of monitoring points and the prevention and control strategies under the background of climate change.
Keywords/Search Tags:Dendrolimus tabμlaeformis, Pinus tabulaeformis, environmental factors, Max Ent, climate scenarios, occurrence trend
PDF Full Text Request
Related items