2007 Vol. 24, No. 6

Biocontrol agents introduced into a Cucumis melo rhizosphere
ZHANG Xin, ZHANG Li-qin, LIN Hai-ping, ZHANG Bing-xin
2007, 24(6): 649-653.
By quantifying cultural microorganisms and analyzing activities of enzymes in the soil, the ecological effect of biocontrol agents, Brevibacillus brevis ZJY-1 and Bacillus subtilis ZJY-116, introduced into the Cucumis melo (cucumber) rhizosphere was studied to improve soil fertility. We used potculture method with three replications, one replication having ten pots of cucumber seedlings with the agent treated soil. 10 g soil was taken to measure every other week after the seedlings come out. Results showed that the introduced strains initially increased the bacterial population, but the influence gradually diminished with further plant growing. Introduction of the two strains caused no significant differences in fungi (P>0.01). Compared to the untreated soil, enzyme activities showed that during the plant growing season, the two biocontrol agents increased fructosidase, and dehydrogenase activity. Thus, the study indicated that introduction of the two strains could increase soil fertility.
Identification of S-genotypes from five cultivars of Pyrus pyrifolia
ZENG Yan-ling, TAN Xiao-feng, ZHANG Dang-quan, ZENG Xiao-feng, LI Xiu-gen, LIU Xian-xiong
2007, 24(6): 654-660.
With natural pollination, fruit from trees having pistil self-incompatible S-alleles will degrade pollen tube RNA resulting in low yield and poor fruit quality. This research identified S-allele genotypes of pear (Pyrus) that served as an important scientific foundation for determining cultivars for pollination and crossbreeding, as well as for establishing a basis on inheriting desired characteristics and improving pear cultivars. Five kinds of pear genomic DNA material were tested based on primary structural characteristics of S-alleles. After designing and synthesizing specific primers and using the polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) system along with TA clone technique, results of sequences were analyzed with bioinformatics software (GeneDoc). Two S-alleles of amplified segments, which had similar sizes, were isolated and identified with their S-genotypes identified as cultivars of Pyrus pyrifolia, namely ‘Jingyu’, S4S24; ‘Jinshui’No.2, S3S21; ‘Xinya’, S4S24; ‘Xizilv', S4S13; and ‘Qingkui’, S1S13.
Effects of ultrasonic wave and with pretreatment solution on floret and cut branch of Chimonanthus praecox during storage
HE Wen-ting, AN Xiao-qin, GUO Wei-ming
2007, 24(6): 661-665.
Maintaining the water status of cut wintersweet(Chimonanthus praecox) is the crux of prolonging its vase life and improving its ornamental quality. Consenescence of cut flower can also be modulated by the species and balanced state of endogenesis incretion. We designed this experiment to reveal effect of ultrasonic wave pretreatmenton cut wintersweet. In vitro floret was cultivated in water in this experiment and its water status changes and longevity were measured after treated with ultrasonic wave(UW) and pretreatment solution(PS). The results showed that the ratio changes of fresh weight and dry weight of floret presented singlet curve during water cultivation, and the change of fresh weight has the same characteristic. The effects of the treatments on floret from high to low in order is UW+PS>UW>ck(control). ABA,iPA and ZRs content changes of petal in cut wintersweet branch treated by ultrasonic wave and pretreatment solution during water storage was measured. We also found that the content of ABA of the treated petal was less than that of ck, but ZRs and iPA contents of treated petal were more than that of ck. So we concluded that the pretreatment of UV and PS can maintain physiological state of cut wintersweet.
Leaf production versus density for seedlings of Camptotheca acuminata
WU Jia-sheng, YING Ye-qing, ZHOU Guo-mo
2007, 24(6): 666-669.
A leaf-producing plantation of one-year old Camptotheca acuminata seedlings was established at five density levels:(A) 1.0 m×1.0 m, (B) 0.5 m×1.0 m, (C) 0.5 m×0.5 m, (D) 0.3 m×0.5 m, and (E) 0.3 m×0.3 m with three replication, to study the effects of density on seedling height, seedling diameter, leaf yield per unit area, leaf number per seedling, and leaf biomass per seedling. The trial did in 2002. Results of the trial showed that (1) density produced no significant differences for average height growth. Also, (2) with increasing density, seedling diameter, per-seedling leaf area, and per-seedling leaf biomass significantly decreased (P<0.05) (yield of A < B < C < D < E). In addition, (3) as density increased from A to C, leaf yield per unit area increased (P<0.05) (leaf yield of A < B < C), while as density further increased from C to E, leaf yield decreased (leaf yield of C > D > E). Thus, for one-year old seedlings of C. acuminatain this trial, the highest leaf yield per unit area could be expected when density E (0.3 m×0.3 m) is used.
Temporal and spatial variation of soil phosphorus in Phyllostachys praecox stands under intensive cultivation management
SUN Da, HUANG Fang, CAI Rong-rong, QIN Hua, ZHUANG Shun-yao, ZHANG Miao-xian, CAO Zhi-hong
2007, 24(6): 670-674.
[Abstract](2289) [PDF](128)
In 2006, we investigated and sampled soils in the main production area of Phyllostachys praecox stands, namely Sankou town, Lin'an city, choosing 1, 5, 10, 15 years plantation of bamboo stands(the paddy soil nearby as the beginning soil of Phyllostachys praecox stands as a check) and each by 4 replications. The objective of this study is to analyse the temporal and spatial variation of soil P along with planting years and the profile depth in Phyllostachys praecox stands during last 15 years under very intensive management models (very heavy fertilizer application yearly and heavy winter organic mulch started after 5 plantation years). Results indicated that, with the prolonging plantation time, the soil P content increased significantly(P<0.05). Soil P content in sub surface layer of 10-20 cm were gradually increased from 0 to 15 years, total P(TP) were 0.39,0.58,0.58,0.85 and 1.57 g·kg-1 respectively, soil organic P were 130.16, 179.83, 183.61, 209.46 and 262.79 mg·kg-1 respectively, and soil available P (Olsen P) were 6.78, 17.41, 33.49, 100.64 and 326.36 mg·kg-1 respectively. The soil Olsen P content rose more rapidly than others with the prolonging plantation time, especially the accumulation velocity and intensity after 10 years. The results indicated that the phosphorus fertilizer was much exceeded which it was needed by Phyllostachys praecox stand. The soil TP,organic P and Olsen P content decreased with the profile depth increase as a whole. However, before the 10 years, the soil TP content was higher at surface and bottom layers, and lower in the middle of sub-surface layer. The soil Olsen P and organic P content from 1 to 15 years had reduced gradually from surface to bottom layers and the reducing rate was expanded with the plantation time. The highly accumulation of TP and Olsen P in the stand soil not only is a big waste of valuable P resources, but also is a potential danger of pollution to its surrounding's water body. We should adjust the management of fertilization in order to save the prime cost, achieve a high yield and protect environment.
Disturbance factors and degraded forest types in the Jinshajiang Watershed of Yunnan Province
HE Li-ping, MENG Guang-tao, CHAI Yong, LI Gui-xiang, FANG Xiang-jing, ZHANG Zheng-hai
2007, 24(6): 675-680.
In the Jinshajiang Watershed, degraded forestland, which included intensively-cut forests, early-restored secondary natural forestland, sparse forestland, brush land, and bare land, was analyzed after disturbance. Disturbance factors were divided into four grades of artificial interference and then ranked. Results of the four grades of disturbance showed:(a) 24 types of degraded forest stands were almost intact forests,(b) 14 types had slight-disturbance,(c) 14 types revealed mid-disturbance, and (d) 19 types showed intensive-disturbance. This grouping will help to better carry out protection of the Jinshajiang Watershed and ecosystem environmental management.
Overlay classification and its application in the remote sensing interpretation of land-use types in Taihangshan area, Hebei
GE Jing-ru, QIN An-chen, ZHAO Xiong-wei, SUN Qiu-hua, LI Ming, ZHANG Rui, JIA Zhe
2007, 24(6): 681-685.
Remote sensing interpretation method includes supervised classification and unsupervised classification. But both of the two methods had their own limitations. In order to obtain the information of land-use type accurately, the research applied a new method of remote sensing interpretation, i.e., the advanced overlay classification. The key to the method was that the overlay images should be recoded partly after supervised classification and unsupervised classification. That is to say the recode was only done on the representative object to make the overlay more adequately. Then another recode was needed after overlay classification. Only by this way good classification effect could be ensured. This paper took Taihangshan area of Hebei for example and compared the merits and defects of the three methods. The results indicated overlay classification was characterized by easy operation, less artificial influence and high precision. The paper provided a powerful technical support for the remote sensing interpretation in future.
Diurnal time-activity budgets of Grus nigricollis for the pre-laying phase in northern Tibet
KUANG Fen-liang, LIU Ning, CANGJUE Zhuoma, LI Jian-chuan, YANG Le, LI Fu-xiu
2007, 24(6): 686-691.
The diurnal activity budgets of Grus nigricollis (wild black-necked crane) were observed in northern Tibet from April to June 2006 using focal animal sampling and all occurrences recording. Results showed that (1) for the diurnal time-activity budgets, activities during the pre-laying phase and their percentage time included five major behaviors:foraging, 43.69%; vigilance, 21.78%; maintenance, 21.69%; locomotion, 7.57%; and breeding, 2.09%; and a miscellaneous group, 3.18%. Additionally, (2) time budgets of vigilance for males was significantly greater (P< 0.01) than females, while there were no significant differences for locomotion. However, the time budgets of three other behaviors and miscellaneous group for females were higher than males. Also, (3) the four behaviors and miscellaneous group were relatively stable before 11:00 am., and then three foraging peaks and one maintenance peak appeared. There were no major peaks for the other behaviors which had a descending trend. Finally, (4) the foraging, vigilance, and maintenance behaviors between males and females were asynchronous from 11:00 to 14:00 and synchronous during other times. With foraging, a peak for males appeared between 12:00-14:00; whereas, for females there were three peaks, namely at 8:00, 12:00-14:00, and 17:00.Behavioral differences of this species, due to gender and location, as well as differences from other cranes were discussed.
Dynamic change of vegetative storage proteins in one-year-old poplar during winter
YU Bin, GUO Yan-qing, PENG Fang-ren
2007, 24(6): 692-695.
In order to study the accumulation mechanism and physiological functions of vegetative storage protein (VSPs) in poplar, the contents of proteins and the compound of vegetative storage proteins in the bark and roots during the course of live through winter of the one-year-old poplar clone 797(Populus deltoids×P. euramericana) were measured and analyzed by SDS-PAGE. The results indicated that the content of proteins in the bark and root increased obviously during winter, and the vegetative storage proteins mainly stored in the bark. The proteins such as 36, 32, 22, 15 kD and etc. changed greatly during the course of through winter, of which these proteins could be detected clearly during the winter and most clear when defoliated. The proteins of 36 and 32 kD are the main types of vegetative storage proteins in poplar.
Architectural analysis of Rhododendron fortunei saplings in Mountain Tiantai, Zhejiang Province
LÜ Zhi-wei, BIAN Cai-miao
2007, 24(6): 696-701.
Rhododendron fortunei lives in many kinds of forests in Mountain Tiantai (29°15' N, 121°06' E). Comparative analysis has been made on the architecture of R. fortunei saplings in the canopy gap of defoliated broad-leaved forest and in scrubs edge of the forest. The results showed that saplings in the canopy gap had thinner and narrower crown with longer branch, wider branch angle to horizon, lower bifurcation ratio and leaf angle to horizon, in comparison with those in the scrubs. All the differences were especially noticeable in the undergrowth. This indicated that the saplings would spread their leaves to receive more sunlight. Saplings had a low angle of leaves, and the leaves were smaller than those of the petiole, which made it possible for them to receive more scattered light. And the ratio of branch diameter, azimuths of branch and leaves had no significant difference. In addition, saplings mainly adopted monopodial branching, and the apical dominance was not evident. So the crown was characterized by sympodial branching in the canopy gap. It followed that the character of ramification of the R. fortunei had the relative stability, but in the two different habitats, bifurcation ratio, branch length, the angle of branch and leaf all varied significantly, and there was a certain tradeoff between the length of branch and the bifurcation ratio.
Physiognomy of Cerasus subhirtella var. ascendens community in Wuyi Mountains, Fujian Province
WANG Xian-rong, XIE Chun-ping, HE Zhi-bin
2007, 24(6): 702-705.
The object is to utilize highly the ornamental resource——Cerasus subhirtella var. ascendens. According to the field investigation into the Cerasus subhirtella var. ascendens community in Wuyi Mountains, Fujian Province, the physiognomic features (including the growing form,life-form spectrum, leaf-size class and leaf form) indicates:Phanerophytes occupied a dominant position in the communities, especially microphanerophy had the highest percentage. The dominant leaf size was microphyll and mesophyll, which occupied more than 90 percentage of total. Simple leave was main leaf form and occupied 91.2% in total. The dominant leaf characteristic was coriaceous. The rates of entire leaves and unentire leaves in total were equal, and caudate leaves and acuminate leaves occupied 67.3% of all leaf apex. All of these indices showed that the community had the characteristic of evergreen broad-leaved forest of south sub-tropic zone.
Plant community properties in a Hemsleya zhejiangensis habitat in Wuyanling Nature Reserve, Zhejiang Province
AI Jian-guo, YU Lin, ZHANG Li-ying, QIAN Liu-qin, ZHANG Teng-chao
2007, 24(6): 706-710.
Hemsleya zhejiangensis (Cucurbitaceae) is an endemic climbing species to Zhejiang Province. The aim is to research the species' natural habitat for cultivation. Raunkiaer's classification was used in a Hemsleya zhejiangensis habitat of Wuyanling Nature Reserve to determine plant community properties. Altogether, 67 species of seed plants belonging to 49 genera of 31 families were found including 16 from tropical and 29 from temperate genera types. Phanerophytes accounted for 90.2%; chamaephytes, 2.8%; geophytes, 5.6%; and therophytes, 1.4%. Leaf size of the vegetation was mainly occupied by medium-sized leaves(60.6%) with leaves having the following characteristics:proportion of simple leaf, 73.2%; herbaceous leaf quality, 69.0%; entire leaf margin, 33.8%; and non-entire leaf margin, 66.2%. Thus, phytocoenosis could be structurally divided into tree layer, shrub layer, and herb layer.
Quantitative analysis of community structure in ecological landscape forests
HE Ying, WEI Xin-liang, CAI Xia, LI Ke-zhui, WANG Zhen
2007, 24(6): 711-718.
The community structure and attributes of ecological landscape forest in Chun'an, Jinhua and Dongyang Cities were studied by standard quadrat method. And all the 30 plots were divided into four types of landscape forests:broad-leaved forest, coniferous and broad-leaved forest, Pinus massoniana forest and Cunninghamia lanceolata forest. The results indicated that both the coniferous and broad-leaved forest and broad-leaved forest were diverse in the species, and had high community evenness. The species in C. lanceolata forest was obviously few, while the stand density was higher than the other three types of forests, reaching 3 967 trees·hm-2. The P. massoniana forest and coniferous and broad-leaved forests had good vertical structure and were more clearly differentiated into spatial layers than broad-leaved forest. The shrubs in broad-leaved forest were so high that the light in woods was not very good. C. lanceolata forest had few shrub and herbal layers with the worse vertical structure. From the angle of spatial distribution pattern, coniferous forest plantations were evenly distributed while broad-leaved forest populations were more concentrated.
Species composition of woody plant communities in urban plazas of Nanjing
ZHI Jian-jiang, LIU Yong, ZHANG Ming-juan
2007, 24(6): 719-724.
Research in species composition and community structure in urban plazas is valuable for optimizing plant landscapes for plazas, improving the ecological security of artificial communities through increasing diversity, and constructing systems of urban, green land. Species composition, ornamental value (of flowers, fruits,leaves, and bodies), and ecological characteristics (frequency and importance value) of woody plants from 24 chief urban plazas in the main districts of Nanjing were determined by field survey. Results showed 1) there were 124 woody plant species, belonging to 91 genera of 53 families. Among these, 62 were tree species, 52 were shrubs, 6 were climbers, and 4 were bamboos. 2) abundant woody plant species, but application of native species was inadequate, primary species were repetitive. 3) planting and arrangement of ornamental plants were not satisfactory. More application of flowering plants, ornamental fruit plants, aromatic plants, as well as the City Tree(Cedrus deodara) and City Flower(Prunus mume) were advocated.
Single factor correlation analysis of diversity in a Eucalyptus plantation understory on Hainan Island
YANG Zai-hong, YANG Xiao-bo, YU Xue-biao, LI Yue-lie, WU Qin-shu
2007, 24(6): 725-730.
This research was conducted to find the critical factors that influenced diversity of Eucalyptus understory vegetation. A comparative analysis of annual rainfall, soil water content, and available soil N, P, and K using the Shannon-Wiener (H') and Simpson's (D) diversity indexes from outdoor sample-plot surveying was undertaken on Hainan Island. Results of a single factor correlation analysis showed woody plants had a significant or highly significant correlation with soil moisture (H', P=0.002 6; D, P=0.002 3), annual rainfall (H', P=0.002; D, P=0.005), as well as available N (H',P=0.014 4; D, P=0.025 3) and available P (H', P=0.004 4; D, P=0.012 0) of the soil. However, the relationship of these factors with diversity indexes H' and D in herbaceous plants were not significantly different. This was probably due to understory shrub development that limited herbaceous growth or due to the vegetative successional stage of the understory in the Eucalyptus plantation.
Topographic differences for vegetation types in Wuyishan National Nature Reserve, Fujian Province
WANG Rong, PAN Wen-bin
2007, 24(6): 731-735.
The objective of this study was to explore the influence of topography on the distribution of mid-subtropical forest vegetation types. Topographic characteristics and vegetation landscape in the Wuyishan Nature Reserve of Fujian Province were determined using a Geographic Information System (GIS) technique and were then analyzed to disclose topographic vegetation distribution differences. Results showed nine vegetation types in the Wuyishan Nature Reserve with zonal evergreen broadleaf and coniferous-broadleaf forests being the main vegetation types and occupying 70.53% of the total area. Forest vegetation had a vertical zonal distribution due to elevation. Slope and aspect had a prominent effect on subalpine meadows, broadleaf coppice forests, and cultivated vegetation types. The coefficients of variation for vegetation types showed that elevation was the most important factor to the distribution of the vegetation.
A management model for tangible and intangible resources in nature reserve
WANG Zu-liang, SHEN Yue-qing, DING Li-xia, Xu Liang, CHENG Xiao-yuan
2007, 24(6): 736-740.
In the past 50 years, the work in China's nature reserves has made rapid progress. However, due to a lack of funds, exploitation for pure economic benefit, which sometimes violated the principles of ecological development, emerged in most of the nature reserves resulting in destruction of the ecological environment. To enhance development and protection of resources in nature reserves, quantifying resources was put forward. First, new classifications of intangible and tangible resources were derived from concepts of resources and nature reserve resource features. Then, intangible resource factors (such as intangibility, being an asset, being a monopoly, having long-term utilization, and value uncertainty) were described in detail. In National Nature Reserve of Mount Tianmu, the study area, common types of intangible resources from nature reserves were proposed, including object name, germplasm resources, landscape view, natural sounds and forest pneuma. Assuming that a tangible resource value from a nature reserve was infinite, the value of intangible resources in these areas was quantified. This new model of resource management suggested that tangible resources should be managed directly and intangible resources indirectly. This would help realize scientific, reasonable, and sustainable development of nature reserve resources.
Ecological regionalization for bamboo in Zhejiang Province
LOU Chong, ZHU Guo-min
2007, 24(6): 741-746.
Based on ecological theories, this research integrated qualitative and quantitative methods to do regional classification for bamboo in Zhejiang Province. We chose 69 cities and counties as investigated subjects. The Index System was constructed by integrating factors related to growth and distribution of bamboo, which is classified as ecological and economic indices, and all indices were standardized after filtering out redundant indices using a correlation analysis. The ecological factors included rainfall in bamboo shooting time, average annual rainfall, average temperatures in the hottest month and in the coldest month, extreme coldest temperature, accumulated temperature(≥ 10℃), accumulated days (≤ -5℃), average annual wind speed, longitude and latitude, and the economic factors were peasant population, population structure, population density, per capita GDP, forest area, forestry contribution, to do clustering analysis. The results showed that 69 cities and counties can be classified into six types, consisting of four sub-types, namely (Ⅰ)the north-easten hilly, plain and low mountainous division, including (Ⅰa)the plain sub-division, (Ⅰb)the hilly and low mountainous sub-division; (Ⅱ)the north-westen mountainous division; (Ⅲ)the middle hilly, basin and lowe mountainous division; (Ⅳ)the south-westen basin low mountainous division; (Ⅴ)the south easten coastal hilly, plain and low mountainous division, including (Ⅴa)the plain sub-division, (Ⅴb)the hilly and low mountainous sub-division); (Ⅵ)the easten penisular division.
Values and logic of regional forestry history: a case study of Zhejiang Province
LEI Zhi-song
2007, 24(6): 747-751.
The researches on the Chinese forestry history are abundant, but little about the regional forestry history. Research on the regional forestry can not only make up for the insufficiencies in the national forestry history and enrich it, but also achieve a profound research on the regional forestry history by separating it from the regional production history and regional agricultural history. The main research logic of regional forestry history is to combine the various researches on regional forestry history by stages, by regions, by contents and by changes, based on both of the dialectical materialism and the historical materialism.
Main environmental factors for forestry insects that become important pests
WANG Yi-ping, YU Zhen-dong, WU Hong
2007, 24(6): 752-757.
This paper discussed why some insects become pests with primary reasons being clarified in order to control pest of forest in the future. These reasons included drought, atmospheric pollution, consequences of global change, and exotic invasive species. Moreover, three key points for rationally allocating different tree species to forests, so as to prevent pest disasters, were put forward, namely:biodiversity to enhance ecosystem stability, a risk dispersing mechanism, and a relative resistance principle. Based on regulation of tree species distribution and time-space structure in forest ecological systems must either promote pest control or at least not increase forest pest damage.
Reasons and countermeasures for enterprises management combining with government administration in northeast stated-owned forest region
XING Hong, LIU Yong, ZHI Ling
2007, 24(6): 758-761.
Based on the analyses on the systematic defect of the enterprises in northeast stated-owned forest region, we consider that enterprise management combining with government administration is the biggest obstacle to systematic reform of northeast stated-owned forest region, which solidify not only the self-enclosed mind and act, but also the pattern of interests. We must rectify relations between the government and the enterprises in the forest region, firstly establish the position of the government of the forest region, then apart the profit-making capital by the way of breaking, exchanging, selling, stocking and renting. Make the enterprises take on the profit-making items and responsible for their own management decisions.
Discussion on transformation of forestry resource-based cities
LIU Jian-ping, WU Yue-hong, CHEN Song-ling
2007, 24(6): 762-766.
On the basis of statistics and literature and with the reference to relevant theories and experience of resource-based cities' transformation, the paper analyzed the current status and necessity of transforming forestry resource-based cities. With the logic of system engineering, the paper studied the contents, key issues and solutions of forestry resource-based cities' transformation. The results showed that forestry resource-based cities' transformation was based on the smooth transformation of various sub-systems such as economics, society, resource and ecological environment. The transformation should focus on four aspects, namely, cultivation of competitive advantages, economics transition oriented by new leading industries, government dominant cities' transition system and breakthrough in forest rights reform. The paper also put forward some measures to construct the cities' innovation systems, improve laws and regulations for the smooth transition of forestry resource-based cities.
Scientific notes
Lilium brownin var.giganteum: a new variety of Lilium from Wenling, Zhejiang
LI Gen-You, CHEN Zheng-hai, YAN Fu-bin
2007, 24(6): 767-768.
Lilium brownii F. E. Brown ex Miellez var. giganteum G. Y. Li & Z. H. Chen,a new variety of lilium from Wenling, in the south of Zhejiang Province,is described. The new variety differs from the previous variety in gigantic bulbs, dia.10-12 cm,and scales more than 100 slices; The corolla's color is pale yellow, and purple outside; The number of flowerlets are usually 5-8.
Influence of grazing on diversity of Dodonaea viscosa-Heteropogonetea contortus herb-shrub community
LI Kun, LI Qiao, CHEN You-qing, ZHOU Xing-yin, CHEN Yan-lin, ZHAO Pei-xian
2007, 24(6): 769-774.
Influence of grazing on biodiversity of Dodonaea viscosa-Heteropogonetea contortus scrub and grass clump in Yuanmou Arid-hot Valley was studied with sample plot investigation and biodiversity analysis. The results showed that the most abundant vegetation species and arthropod species were in the non-disturbed scrub and grass clump. Formica fusca was the dominant species in its arthropod community. And the highest diversity index and the evenness index were found, as well the lowest predominant index. The poorest vegetation species and arthropod species were in the overgrazed scrub and grass clump. The lowest diversity index was found in its arthropod community in the shrub-grass layer. More abundant vegetation species and arthropod species were in the scrub and grass clump with certain long-term grazing. The lowest evenness index and highest predominant index were found in its arthropod community. The piercing-sucking insects were predominant in the shrub-grass layer, and Monomorium mayri was predominant in the litter-layer in the grazed clumps. The species component changed in the overgrazed clump, biodiversity in the ecosystem depressed greatly, the arthropod community was instable, and the habitat degraded. Grazing had more effect on the biodiversity of the litter-layer arthropod communities than that of in the shrub-grass layer.
Optimum conditions for rapid propagation with clones of Acacia implexa
HE Wen-jin, HUANG Qi, CHEN You-qiang, DAI Rong-chun, LIN Si-zu
2007, 24(6): 775-778.
Acacia implexa is an excellent multipurpose tree species in South China, however seed propagation will cause segregation of inheritable characteristics and then, limit its utilization. This study looked at the use of tissue culture to clone trees with three plant growth regulators (6-BA; NAA, ZT) in different levels, and appropriate methods for possible ways to prevent vitrification of adventitious buds by orthogonal experiment L9(34). Results of experiments on micropropagation of young stem sections for selected adult trees of A. implexa showed that a suitable medium for adventitious bud differentiation of the stem sections with axillary buds was:MS (Murashige and Skoog's medium)+1.0 mg·L-1 BA(6-benzyladenine) +0.2 mg·L-1 NAA(α-naphthalene acetic acid)+1.0 mg·L-1 ZT(zeatin), a suitable medium for adventitious bud multiplication was:1/2 MS(NH+4:NO-3=1:2)+1.0 mg·L-16-BA+0.05 mg·L-1 NAA, and a suitable medium for improving roots was:1/2 MS+0.1 mg·L-1 NAA. After transplanting, over 70% of the tube plantlets survived.