Assessment Of Forest Ecosystem Health And Selection Of Indicator Insects In YiWuLv Mountain

The forest ecosystem, with the largest area, prolific materials and the most complicated structure, is the main body of the terrestrial ecosystem. The health status of the forest ecosystem directly affects the safety of human ecology and sustainable development. Forest health is a basis for sustainable development of forest resources. The forest ecosystem health assessment is a premise that protects and restores forest ecosystem health. The analysis and assessment of forest ecosystem health is important to push forward the sustainable development of forestry and ecological safety.The main protection objects of the YiWuLv Mountain national nature reserve are "the special species of East Asia, Chinese pine","well reserved natural coniferous and broadleaved mixed forest in Huabei flora" and some precious wild animal species, such as black stork. The YiWuLv Mountain national nature reserve is the forest ecosystem and wildlife nature reserve and locates in warm temperate semi humid climate zone. Its flora is of North China flora, neighboring to Mongolian flora and Changbai flora. Therefore, it is significant to YiWuLv Mountain by protecting forest ecosystems health, maintaining the ecosystem balance, giving full play to the forest ecological system function and keeping harmonious development with human, economic and society.This study based on the YiWuLv Mountain national nature reserve with32plots by30m X20m. The forest ecosystem health was assessed and the indicator insects were selected. The results showed that:This study assessed the forest status of YiWuLv Mountain national nature reserve from the forest ecosystem structure, biodiversity, forest vigor, soil health status, and resistance respectively. A total of22indicators were selected to construct the forest ecosystem health assessment system. The22indicators included crown layer, canopy density, age structure of stand, stand density, nature closeness, stand structure index, tree richness, tree Shannon-weiner index, shrub richness, shrub Shannon-weiner index, herbaceous richness, herbaceous Shannon-weiner index, family richness of insect, Shannon index of insect, forest cumulate quantity, number of sapling quantity, leaf area index, degree of combustibility, forest pest and disease damage degree, artificial interference, soil texture, soil thickness and soil moisture content. The principal component analysis and cluster analysis on forest ecosystem health of YiWuLv Mountain showed that the health status of32plots is good, and divided into21health forest plots,6sub-health forest plots and5general health forest plots.In order to study the insect community composition,4392insects were collected, which including340species from112Families of11Orders. Coleoptera, Heteroptera and Hymenoptera insects occupied the largest number of species in the community, accounting for31.18%,24.48%and9.9%, respectively. The small group included Diptera, Heteroptera, Orthoptera, Mantodea, Dermaptera, Mecoptera, Neuroptera, Trichoptera. A total of412Carabidae insects were collected, belonging to7Genus,21species and362Cerambycidae insects were collected, belonging to39species,5Sub-Families. There was a certain degree of difference with different health forest ecosystems on the composition of insect community.155insects and35species were collected in each plot of the health forest ecosystems;119insects and26species were collected in each plot of the sub-health forest ecosystems;86insects and19species were collected in each plot of the general health forest ecosystems. The species and number of insects in health forest ecosystems were significantly higher than those of sub-health and general health plots. The total number of common insect communities was56species in different health forest ecosystems, accounting for16.47%. A larger proportion of endemic species existed in different health forest ecosystems in a medium dissimilarity level.The insect community function group of the YiWuLv Mountain forest ecosystem was divided into herbivorous insects, predatory insects, parasitic insects and other insects. The order of species and individuals was herbivorous insects>predatory insects>parasitic insects>other insects. The insect community function group also existed a certain degree of difference in different health forest ecosystems. The herbivorous insects occupied the highest proportion in general health forest. On the contrary, the herbivorous insects occupied the lowest proportion in health forest. The number and species of natural enemy that constituted byerbivorous insects and predatory insects was the highest in all forest types. There was a strong restrict between insect communities in the health forest with more natural enemy insects more complicated food web, more stable the insect communities, stronger resistance to outside interference, and more stable than the sub-health and general health forest ecosystem.The community composition and diversity between Carabidae and Cerambycidae existed significant differences in different health forest ecosystems. The number and species of Carabidae were the largest in the health forest and the diversity was higher than the other types. The Cerambycidae community also had the same trend.7Carabidae species and11Cerambycidae species were selected through the indicator value in YiWuLv Mountain forest ecosystem, including Harpalus calceatus (Duftschmid), Carabus lafossei coelestis Stew, Chlaenius cicumdatus Brulle, Amarysius altajensis Laxmann, Leptura aethiops Poda, Mesosa myops (Dalman), Moechotypa diphysis (Pascoe), Plagionotus christophi (Kraatz), Acanthocinus aedilis L. and Saperda carcharias (Linnaeus). The indicator of sub-health species included Calosoma maximowiczi Morawitz, Calosoma inguistor L., Prionus insularis Motsch, Asemum amurense Kratj and Trichoferus campestris (Faldermann). The indicator of general health species included Carabus (Coptobabrus) smaragoinus Fischer, Calosoma maderae chinense Kirby and Massicus raddei(BIessig).