Time filter

Source Type

Zhu L.-Q.,Zhejiang GongShang University | Zhang Z.,Research Institute of Forest Ecology
Pan-Pacific Entomologist | Year: 2013

This paper proposes a Lepidoptera insect image recognition method based on extracting image features using superpixels segmentation, encoding the features with Locality-constrained Linear Coding (LLC), aggregating codes with max pooling, and then classifying them with classification and regression tree (CART). This method used the natural scale color patterns on the insect wings as the basis for recognition, which can avoid the complicated chemical processing needed for venation based recognition. The method is tested in a dataset including 579 image samples from ten species of Lepidoptera species, and the recognition error rate is below 5%. The method also exhibits good performance with respect to time cost. The experimental results suggest that on the task of recognizing Lepidoptera species, the proposed method has state-of-the-art performance with high efficiency. © Pacific Coast Entomological Society.


Wang X.-Y.,Research Institute of Forest Ecology | Yang Z.-Q.,Research Institute of Forest Ecology | Gould J.R.,Animal and Plant Health Inspection Service | Wu H.,Forestry Bureau of Sanming City in Fujian Province | Ma J.-H.,Forest Pest Control Station of Qinghai Province
Biological Control | Year: 2010

Spathius agrili Yang (Hymenoptera: Braconidae) is a newly described and important idiobiont ectoparasitoid of the emerald ash borer (EAB) that has excellent potential as a biological control agent against EAB populations in the USA. In order to understand the ecological factors involved in the search and discovery of concealed hosts by S. agrili, we investigated the behavioral responses of adult female wasps to potential semiochemicals from host plants, hosts, and host frass as well as to vibration signals from host feeding and movement. Using a bioassay, we showed that S. agrili first finds the host's habitats by detecting the volatile compounds emitted by ash. In the second phase of host location and acceptance, the parasitoids detect the mechanical vibrations produced by host feeding and movement under the surface of the bark and then probe to find the EAB larvae. Contact chemicals seem to play little or no role in short-range host finding. Female wasps avoided laying eggs on EAB larvae already parasitized and thus paralyzed. We hypothesized that female wasps were not attracted to these larvae due to their lack of feeding or movement. While an induced paralysis in the host is instrumental in avoiding superparasitism, we cannot rule out that S. agrili females also use an oviposition pheromone to deter conspecific females. Together, these results suggest that vibration and olfactory cues play significant roles in distinct phases of S. agrili host habitat and host location behaviors. © 2009 Elsevier Inc.


Tian Y.,Sun Yat Sen University | Tian Y.,Research Institute of Forest Ecology | Huang Z.,Research Institute of Forest Ecology | Xiao W.,Research Institute of Forest Ecology
Journal of Environmental Sciences | Year: 2010

Non-point source water pollution generated by agricultural production is considered a major environmental issue in the Three Gorges Reservoir Area (TGRA) of China. The Annualised Agricultural Non-Point Source Pollution (AnnAGNPS) model was selected to assess the impact of the application of various management treats, including seven crops, five fertilizer levels and three-group management practice scenarios, on water quality from Heigou River Watershed in TGRA. The scenario subsets include conservation tillage practice (CTP), conservation reserve program (CRP) and conversion of cropland into forestland program (CCFP). Results indicated that tea can not be replaced by other crops because comparatively tea resulted in a higher sediment yield. CTP with no-tillage was more effective to reduce sediment yield, but could increased nutrient loss. CRP reduced sediment yield significantly, but slightly benefited on nutrient loss. CCFP reduced not only sediment yield but also the nutrient loss significantly. The conversion of cropland with a slope greater than 10° into forestland was found to be the best scenario as the sediment yield export is less than 5 tons/ha and nutrient loss is within the permissible limit. © 2010 The Research Centre for Eco-Environmental Sciences, Chinese Academy of Sciences.


Yao Y.-X.,Research Institute of Forest Ecology | Yao Y.-X.,U.S. Department of Agriculture | Duan J.J.,U.S. Department of Agriculture | Hopper K.P.,U.S. Department of Agriculture | And 2 more authors.
Annals of the Entomological Society of America | Year: 2016

We describe a new species of egg parasitoid, Oobius primorskyensis Yao & Duan n. sp., collected from the emerald ash borer Agrilus planipennis Fairmaire (Coleoptera: Buprestidae) near Vladivostok, Russia. Morphological and molecular analyses indicate that this taxon is sufficiently distinct from Oobius agrili Zhang & Huang 2005 to merit species status. Furthermore, DNA sequence divergence between O. primorskyensis and specimens in culture of Chinese origin suggest that O. primorskyensis is molecularly distinct from Oobius previously imported into the United Stated and released as biological control agents of emerald ash borer. Laboratory observations showed that O. primorskyensis also differs from O. agrili in diapause pattern. When reared with A. planipennis eggs at 25 ± 1.5°C, 65 ± 10% relative humidity, and a photoperiod of 16:8 (L:D) h, nearly 100% of O. primorskyensis diapaused at the second and third generations after their parents had diapaused, whereas a majority (60-96%) of O. agrili did not diapauses for 11 sequential generations. Diagnosis of the species with respect to O. agrili is provided. The new species is a natural enemy of A. planipennis in its native range and may be considered for introduction against A. planipennis in North America. © Published by Oxford University Press on behalf of Entomological Society of America 2016. This work is written by US Government employees and is in the public domain in the United States. Version of Record, first published online May 3, 2016 with fixed content and layout in compliance with Art. 8.1.3.2 ICZN.


Liu J.,Chinese Academy of Forestry | Liu J.,Key Laboratory of Tree Breeding and Cultivation | Yang W.,Chinese Academy of Forestry | Jiang Z.,Chinese Academy of Forestry | And 3 more authors.
Shengtai Xuebao/ Acta Ecologica Sinica | Year: 2011

Thuja sutchuenensis Franch. is a critically endangered plant that is endemic to China. Currently, no research has addressed its endangered status from the perspective of its photosynthetic mechanism. Light is one of the most important environmental factors that can affect plant survival and growth and could become a major limiting factor for natural regeneration. Therefore, we focused on the adaptive ability of T. sutchuenensis seedlings under three light levels (L0 = full light; L1 = 50% full light; L2 = 25% full light) by comparing their photosynthetic capacity, chlorophyll fluorescence parameters, and chlorophyll content. We found that shading resulted in increases in the apparent quantum efficiency (α) and maximum leaf net photosynthetic rate (P max). At lower light levels, the dark respiration rate (R d), light compensation point (LCP), and light saturation point (LSP) declined. For the chlorophyll fluorescence parameters, PS II primary energy conversion efficiency (Fv / Fm), PS II potential activity (Fv / Fo), and photochemical efficiency of PS II in the light (Fv'/ Fm') were significantly higher at lower light levels than at L0, with parameters at L2 higher than at L1. Non- photochemical quenching (NPQ) also had a higher value under shade than under full light, and peaked at L1. With a decrease in light intensity, photochemical quenching (PQ) and the electron transport rate (ETR) decreased. Shading also caused a significant increase in leaf chlorophyll content (Chla + Chlb) per cm 2. These results indicate that T. sutchuenensis can tolerate a wide range light conditions, especially low light, and has internal regulatory mechanisms for responding to light level. Therefore, low light under canopy cannot be the decisive limiting factor for natural regeneration of T. sutchuenensis populations.


Wang X.,Research Institute of Forest Ecology | Cheng R.,Research Institute of Forest Ecology | Xiao W.,Research Institute of Forest Ecology | Guo Q.,Research Institute of Forest Ecology | And 2 more authors.
Shengtai Xuebao/ Acta Ecologica Sinica | Year: 2010

Relationship between standing vegetation and soil seed bank in flooded area, non-flooded area and control area in water-level-fluctuating Zone of Three Gorges Reservoir at the beginning after charging water was studied with a germination method. The results showed that the standing vegetation was composed of 100 species in 71 genera of 47 families in flooded area, and 223 species in 163 genera of 84 families in non-flooded area, and, the main families were Asteraceae, Leguminosae, Poaceae, Rosaceae, Cyperaceae. The species life of the standing vegetation is mainly composed of annual herbaceous species which had a short growth cycle and strongly adaptability accounted for majority proportion. Shrub and fluorescence accounted for 19% in flooded area. In non-flooded area, annual herbaceous species, perennial herbage species, shrub, fluorescence and arbor accounted respectively for 20. 45%,36. 36%, 28. 28%, 15%. The life form percentage in control area which existed the original vegetation were respectively 23. 24%, 28. 18%, 32. 02%, 17. 05%. Compared with those in control area, both species diversity indices and richness indices of the standing vegetation decreasedsignificantly in flooded area, and however increased significantly in non-flooded area. Evenness indices were all decreased in both flooded and non-flooded area. The species number of the seed bank in flooded area and non-flooded area were respectively 79 and 108, with 9 and 38 species more than that in control area. There existed significant differences in the soil seed bank among flooded area, non-flooded area and control area, with an average seed density being (12667 ± 2225. 25) seed banks per m2, (38013 ± 9796. 04) seed banks per m2 and (18715 ± 8234. 77) seed banks per m2, respectively. Compared with control area, flooded area had lower seed bank density by 32.32% and non-flooded area had higher seed bank density by 103. 12%. Herbaceous species accounted for majority proportion in these two sites, and annual herbaceous species seeds were higher proportion than that of the perennial herbaceous. The indices of biodiversity, richness, evenness of the seed bank had similar trends to the standing vegetation, with a smaller extent of the change. There were 9, 40, and 15, co-occurrence species in both the standing vegetation and the seed bank respectively in flooded area, non-flooded area and control area. Their Sorensen similarity coefficients of species composition between the seed bank and the standing vegetation were respectively 0. 328, 0. 241 and 0. 186. The results indicated similarity coefficients were lower in the water-level-fluctuating Zone of Three Gorges Reservoir at the beginning after charging water, and soil seed bank of dominant species that did not quickly form dominant communities in the standing vegetation. Which had a great relationship with the shorter formation time of water-level-fluctuating zone of Three Gorges Reservoir.


Wang D.,Research Institute of Forest Ecology | Wang B.,Research Institute of Forest Ecology | Niu X.,Research Institute of Forest Ecology
Journal of Tropical Forest Science | Year: 2014

Tree species have strong influence on soil carbon storage but the interactions are not well understood. Using the path analysis method, the response of soil carbon pool to changes in tree species were studied by comparing soil organic carbon quantity and quality in primary mixed broadleaved Korean pine (Pinus koraiensis and Quercus mongolica), natural Korean larch (Larix olgensis) and natural Chinese pine (Pinus tabulaeformis) forests in north-east China. Results showed that the effects of tree species on soil total organic carbon, recalcitrant organic carbon and microbial biomass carbon occurred at 0-40 cm depth. The mixed forest increased organic carbon and carbon fraction concentration over pure Korean larch and Chinese pine stands. Path analyses suggested that the effects of tree species on soil organic carbon mostly passed through direct effects on recalcitrant organic carbon and indirect effects on microbial biomass carbon but not through water-soluble organic carbon. Microbial biomass carbon may be used as a sensitive indicator of changes in soil organic carbon. Moreover, the response of recalcitrant organic carbon to forest conversion will also determine the magnitude of feedback of soil carbon to forest type due to its large storage in soil. © Forest Research Institute Malaysia.


Yang H.-L.,Research Institute of Forest Ecology | Li D.-Q.,Research Institute of Forest Ecology | Duo H.-R.,Research Institute of Forest Ecology | Ma J.,Minzu University of China
Forest Research | Year: 2010

Based on SPOT 5 satellite image obtained on June 2004 and field investigation, the vegetation of Fanjing Mountain Nature Reserve was analyzed dirough processing and correcting the images by using the ERDAS image processing software. 7 types of vegetation were identified. The spatial distribution and other relevant information of each vegetation type were obtained by using ArcGIS. The occurrence frequency of Guizhou Golden Monkey (Rhinopithecus brelichi) in each vegetation type indicated that the broadleaf evergreen and deciduous mixed forests, the broadleaf evergreen forests were the main vegetations selected by the monkeys. The results of this research could provide a sound basis for reserve management and planning,preservation of the Guizhou Golden Monkey in this reserve.


Wang B.,Research Institute of Forest Ecology
Beijing Linye Daxue Xuebao/Journal of Beijing Forestry University | Year: 2015

Evaluating the ecological status of forests and understanding the accomplishment so far of establishing our study of the ecology on a firm footing at the national level, demands a complete system for continuous observations and inventory records. The technology of continuous observations and an inventory of a complete index system of forest ecosystem services (referred to as TCOICISFES) includes two subsystems: continuous investigation of field observations (CIFO) and distributed measurement evaluation (DME). In CIFO, the principles of the layout of the system of observations have been established. China has constructed the largest nationwide network of forest ecological stations in the world and systematically assembled facilities and equipment. Hence, the CIFO indices can be described and are measurable at national forestry standards. Simultaneously, these standards were utilized to conform to data acquisition and transmission in the CIFO system. In the process of building the DME system, a distributed measurement method was created, an index system of evaluation was examined and established and data of national forest resources and related statistics were integrated and coupled. As well, we propose a system of correction coefficients for forest ecological functions and integrated with a series of evaluation formulas and a package of models. The TCOICISFES can be used along with the national forest resource inventory to function as one of the key technologies for observing and evaluating forest ecological conditions. This includes an inventory of national forest ecosystem services, estimates of ecological benefits derived from returning farmland to forests and a green national economic accounting system. ©, 2015, Beijing Forestry University. All right reserved.


Chen Z.,Research Institute of Forest Ecology | Yu H.,Research Institute of Forest Ecology | Shang H.,Research Institute of Forest Ecology | Cao J.-X.,Research Institute of Forest Ecology
Forest Research | Year: 2016

Elevated ozone will cause substantial changes of root architecture that may ultimately affect the function of root and thereby the tree's overall health and ability to cope with stress. The effects of elevated ozone on the root of trees included root growth, fine root dynamics and turnover, root respiration, carbohydrates in roots, mycorrhiza growth and rhizosphere soil microbiology. The effects of ozone stress on tree root are relevant to the concentration of ozone, species, tree age, community composition and planting conditions. At present, there is limited information about the mechanism of the effects of ozone on root. It is necessary in the future to strengthen the in-situ observation and quantitative analysis of root architecture, response of endogenous hormone to ozone, stress signal sensing, transduction and interaction with other signaling pathway, and the molecular biological mechanisms of roots response to ozone. © 2016, Chinese Academy of Forestry. All right reserved.

Loading Research Institute of Forest Ecology collaborators
Loading Research Institute of Forest Ecology collaborators