《白孔雀》中植物意象的生态思想解读

在英国小说家D·H劳伦斯长篇处女作《白孔雀》中,作者对自然环境尤其是林中万物描写得生动细腻。本文通过文本细读的方式,拟结合生态思潮中涌现的新观点来解读从小说中选取的树\树林及香雪球\牡丹花的象征寓意和潜在的生命力,展示了包括人在内的自然万物生存发展的独一无二的重要性,号召世人敬畏生命,尊崇自然。

Radial Variation in Sap Flux Density as a Function of Sapwood Thickness in Two Eucalyptus ( Eucalyptus urophylla ) Plantations

Radial variation in sap flux density (SFD) as a function of sapwood thickness is of importance in accurately estimating sap flux through sapwood area which, in turn, decides the precision of heat pulse application. However, until now, only a few studies have evaluated the magnitude and significance of sampling errors associated with radial gradients in SFD, which were based on the small monitoring measurement data from a few trees. Based on one year of heat pulse observation of two 3 - 4 years old Eucalyptus urophylla S. T.,P Blake plantations in Leizhou Peninsula, Guangdong Province, China, a way of data processing was developed to treat with the lots of SFD data measured from 39 trees. It was found that the radial variation in SFD as a function of sapwood thickness in the two eucalyptus plantation sites could be expressed as y = 3. 667 5x(3) - 7.295 5x(2) + 3.682 6x + 0. 567 4 (R-2 = 0. 939 1, n = 80, P = 0.01), where y is the ratio of SFD of a sensor to the average of four data in different depths, x is the ratio of a sensor depth to tire radial sapwood thickness. It was the same (as in the following equation) in Jijia site, y = 5.006 2x(3) - 9.116 1x(2) + 4. 454 4x + 0.463 4 (R-2 = 0. 806 9, n = 72, P = 0.01) in Hetou site. From cambium to heartwood, SFD showed some increases at first and then decreases continuously. However, because die trees were very young, the maximum SFD was only 0. 33 - 0. 36 times more than the minimum.

Effect of Continuous Cropping on Leaf Nutrient and Growth of Different Species of Poplar Plantation

[Objective]The paper was to study the effect of continuous cropping on leaf nutrient and growth of different species of poplar plantation.[Method] The tree height,diameter at breast height（DBH）,volume of different generations and species of poplar plantation in poplar production area in northern Jiangsu Province,as well as TN,TP and TK content in their leaves were determined through field investigation and indoor experiment.[Result] With the increasing generation,the changes of TN,TP and TK content in the leaves of different ages of two varieties of forest stand were also different.However,with the increasing tree ages,TN,TP and TK contents in leaves showed decrease trend.With the increasing generation,the changes of tree height of I-69 and I-72 poplar showed the similar trend.The effect of increasing generation on tree height of 7-year-old and 10-year-old poplar was relatively stable,showing decrease trend from generation to generation.The tree height of 4-year-old poplar first increased and then decreased with the increasing generation.The changes of DBH along with different generations were basically consistent with the changes of tree height.With the increasing cultivation generations,the volume of 7-year-old and 10-year-old poplar decreased with significant difference.[Conclusion ] The result provided basis for rational fertilization and management of poplar plantation,improvement of productivity of poplar plantation,and achievement of sustainable management of plantation.

Dynamics of profiles and storage of carbon dioxide in broadleaved/Korean forest in Changbai Mountain

CO2 concentrations at different heights in a broadleaved/Korean forest (with a mean height of 26 m) were measured with infrared gas analyzer IRGA (model 2250D, LI-COR Inc. and LI-COR, 820) from Aug. to Oct. of 1999, Apr. to Jul. of 2000, and from Aug. 2002 to Sept. 2003. Based on the collected dada, the diurnal and seasonal dynamics of profiles and storage of carbon dioxide in the forest were analyzed. The diurnal CO2 profiles showed that the vertical distribution of CO2 concentration were different for daytime and nighttime, and the CO2 concentration was highest close to forest floor, no matter at daytime and nighttime. The seasonal profiles of CO2 showed that stratification in the canopy was evident during growth season. CO2 concentrations at different heights (60 m to 2.5 m) had a little change in March, with a difference of 10 mmolmol-1, but had a significant change in July, with a difference of 60 mmolmol-1. In July, there also existed a greater gradient of CO2 concentrations at canopy (22, 26 and 32 m), with a difference of 8 mmolmol-1. The calculated total storage (ΔC/Δt ) of CO2 in the air column with height of 40 m beneath eddy covariance instrument was negative, and made a little contribution to NEE.

Effects of climate factors on the height increment of poplar protec-tion forest in the riverbank field

Based on the data of stand investigation and stem analysis, the effects of climate factors on the poplar protection forest increment in the riverbank field of the Dalinghe and Xiaolinghe rivers of Liaoning Province, China were studied by step-wise regression procedure and grey system theories and methods. A regression model reflecting the correlation between the height increment of poplar protection forest and climatic factors was developed. The order of grey relevance for the effect of climatic factors on the height increment of poplar protection forest is: light>water>heat, and it could be interpreted that the poplar increment was mainly influenced by light factor, water factor, and heat factor. This result will provide scientific basis for the in-tensive cultivation and regeneration of the poplar protection forest in riverbank field in similar regions in China.

Present status and conservation strategies of mangrove resource in Guangdong, P. R. China

According to the survey of Guangdong mangrove resource in 2001 and authors field investigations in the past 5 years, the total mature mangrove land area of Guangdong Province was estimated at 9084 hm2, accounting for 41.4% of total mangrove land area of China. These mangrove forests totally consisted of 50 species belonging to 28 families, distributed at more than 100 locations along the coastlines of Guangdong and most of them present a high dense and dwarf appearance. The Ass. Avicennia marina is the most dominant mangrove association. The investigation results showed that the mangrove forests with coverage rates above 0.7 accounted for 68.0% of the total mangrove land area of the province and 77.8% of mangrove forests was less than 2 m in tree height. Since 1950, 54.6% of mangrove forests have disappeared due to paddy rice reclaim, aquaculture and city constructions. Derivational conservation efforts are still weakly empowered and should be strengthened intensively. The author suggested that mangrove laws and regulations should be enforced, mangrove scientific research should be strengthened; and mangrove conservation awareness of local community should be raised on conservation of mangroves.

Effect of water extracts of larch on growth of Manchurian walnut seedlings

A study was conducted to detect the effect of water extracts from different parts such as root, bark, branch and leaf, of adult larch, Larix gmelini, trees on growth of Manchurian walnut, Juglans mandshudca, seedlings and the allelopathy between the two tree species. Four concentrations （100 g. kg i, 50 g. kg^-1, 25 g. kg^-1 and 12.5 g. kg^-1） were prepared for each kind of extracts. Result showed that the water extracts with low and moderate concentrations accelerated the growth of collar diameter and increased biomass and root/shoot ratio of walnut seedlings. The water extracts from branches and barks with low and moderate concentrations accelerated the height growth of the seedlings, while those from leaves and roots slightly decreased the height growth of seedlings. The fact that application of water extracts of larch improved the growth of Manchurian walnut attributes possibly to the allelopathy between the two tree species.

Effects of Climate Warming on Phenological Characteristics of Urban Forest in Shenyang City,China

Change in plant phenology is one of the most sensitive ecological responses to climate warming. Little information is known about the effects of climate warming on phenology of urban tree species in the northern forest of China. In this study, we investigated the phenological characteristics of the main tree species in the urban forest of Shengyang City in China and the correlation between phenology and atmospheric temperature from the discontinuous data during past 42 years over three time periods(from 1962 to 1965, 1977 to 1978, and 2000 to 2005). The results showed that the annual average temperature in Shenyang City showed an increasing trend and increased by 0.96℃ from 1962 to 2005 due to climate warming. The germination phenology of the urban trees was negatively correlated with the temperature in winter and early spring. The leafing phenology was mainly influenced by the temperature in spring before leafing. Influenced by climate warming, the germination, leafing, and flowering phenologies of this urban forest in 2005 were 14, 13, and 10 days earlier than those in 1962, respectively. We inferred that further warming in winter might prolong the growing season of urban trees in the northern forest of China.

Coffee Agroforestry with Some Timber Shade Trees： Study on Carbon Stock, Mineral Cycle, and Yield

Coffee cultivation by using shade trees is simple of agroforestry, this system could get better ecosystem service and sustainable agricultural. The aims of this research are to study the possibility of some species of industrial woods as shade trees of Coffea canephora. The research was conducted in Jember, Indonesia （45 m asl., D rainfall type according to Schmidt and Ferguson）, and arranged in split plot design. The main plots were （A） coffee-T, grandis （3 m × 2.5 m ×12 m）, （B） coffee-P, falcataria single row （2.5 m ×6 m）, （C） coffee-P, falcataria double rows （3 m× 2.5 m × 12 m）, （D） coffee-P, falcataria vat. Solomon （3 m× 2.5 m × 12 m）, （E） coffee-M, azedarach （3 m ×5 m ×22.5 m）, （F） coffee-H, macrophyllus （3 m ×5 m ×12.5 m）, and （G） coffee-Leucaena sp. （3 m × 2.5 m） as control. The sub plots were coffee clones, i.e., BP 534, BP 409, BP 936, dan BP 939. Among those timber trees, Leucaena was planted as the alternative shade trees. The result showed that in comparison with control, all of coffee agroforestry system improved carbon sequestration. Total C-stock on （B） was highest, i.e., 1,007 percent to control while the lowest one was （A） 317.44% to control. During one year observation, litter weight of H. macrophyllus was heaviest followed by T. grandis. The lightest litter was obtained from M. azedarach. Based on its mineral contents, litters of T. grandis potentially supplied back nutrients that equaled to total Urea, SP-36, KC1, Dolomite, and Kieserite as much as 574.14 g; P. falcataria 287.57 g, P. falcataria var. Solomon 453.59 g, M. azedarach 450.84 g, H. macrophyllus 877.56 g, and Leucaena 445.12 g per tree per year. Because of heavily fallen leaves of M. azedarach during dry season and conversely too dense shading of H. macrophyllus, bean yield at 4 and 5 years old by using both species were consistently lower than that under T. grandis, P. falcataria and control. At those ages, effect of clone on cherry yield was still not consistent but there was a tendency that BP 939 was most productive, while BP 534 was the less. Its outturn was not influenced by agroforestry system but by clones. The agroforestry pattern influence physical bean characters, more dense of shading, more single bean and empty bean. That bean abnormality also genetically, on BP 939 percentage of round and empty bean was highest while on BP 936 was lowest. It was concluded that coffee agroforestry improve ecology service, but M. azedarach and H. macrophyllus were not appropriate to be used as coffee shade trees. P. falcataria is recommended as an alternative shade tree beside Leucaena sp.

Economics of the plant species used in homestead agroforestry on an offshore Sandwip Island of Chittagong District, Bangladesh

This study was performed in five villages of Sandwip Upazila, Chittagong district with a view to identify the tree resources, utilization pattern and economic return of major fruit and timber tree species. Information collected from a total of 60 households ranging from marginal, small, medium and large categories. Number of plant species increased with the increase of homestead area. A total of 33 plant species were recorded from the homegarden, of which 19 were fruit and 14 were timber tree species. Considerable number of vegetables was also planted under the shade of the homestead trees. The investment analysis showed that average benefit-cost ratios were greater than one, net present values were positive and internal rate of returns were more than 10%. Long term investment on horticulture and timber tree species is highly profitable if species like Artocarpus heterophyllus, Cocos nucifera, Tectona grandis and Swietenia macrophylla are planted.

Tree and shrub species preferences and planting materials used by sub-religious communities in the village groves of floodplain area of Bangladesh

An exploratory study of the traditional homestead forest of two different religious groups (Hindu and Muslim) in one selected floodplain area of Bangladesh was conducted over a period of six months from January to June 2002. The species' (both tree and shrub) preferences, similarities, use and sources of planting materials, spacing and location of species in the homesteads of both Hindu and Muslim communities were studied. It was found thatMangifera indica as tree species andOcimum sanctum as shrub species were the best preferred species of the Hindu community.Artocarpus heterophyllus as tree species andLawsonia inermis as shrub species were found best preferred by the Muslim community. Floristic similarities between the two groups were found 86.57% in tree species and 78.48% in shrub species. Both seed and seedlings of tree and shrub species as planting materials were used by the highest percentage of both the religious communities. For tree species, homegarden was reported to be the highest source (39%) and for shrub species, nature was the highest source (40%), which was found in the Hindu community. Key words Species preferences - Species similarity - Planting materials - Hindu - Muslim - Homestead forests - Floodplain area - Bangladesh CLC number S72 Document code A Biography: Md. Danesh Miah (1971): male, Assistant Professor in the Institute of Forestry and Environmental Sciences, University of Chittagong, Chittagong 4331, Bangladesh.Responsible editor: Chai Ruihai

How Does the Blue C Stock Vary in Restored and Degraded Wetlands Across Land Cover Mosaics? Evidences from Medinipur Coastal Plain, India

Coastal wetlands are of paramount importance as major reservoirs of blue carbon(C),playing a crucial role in providing nature-based solutions to mitigate climatic changes.This research aimed to analyse the dynamics of total blue C(TBC)and its components;viz.soil organic C(SOC),below ground C,and above ground C;as well how they are influenced by land use/land cover(LULC)categories and wetland situations.Subsequently,study were identified as one restored wetland and another degraded wetland in the Medinipur Coastal Plain,India.The LULC categories were analyzed using Pleiades 1A and 1B satellite imagery,corresponding to the restored and degraded wetland,respectively.The quantification of SOC was based on point-specific sample data collected from both wetlands(nr=250;nd=84).Above ground biomass(AGB)was appraised employing allometric relationships involving field-measured dendrometric variables.Below ground biomass values were calculated using indirect allometric equations that take into account the AGB values.Integrating all the components,TBC stock of the restored and degraded wetlands were estimated at 246710.91 Mg and 7865.49 Mg,respectively.In the restored wetland,dense mangrove and open mangrove exhibited higher concentrations of blue C components,while other LULC categories demonstrated moderate to low densities.In the degraded wetland,the open mangrove category rechigh densities of C pools,whereas herbaceous vegetation,bare earth and sand,and waterbody exhibited lower concentrations.The results portrayed significant disparities(P<0.05)in blue C pools among different LULC categories in both wetlands.Furthermore,it was evident that wetland type and LULC category had notable(P<0.001)impacts on TBC dynamics,both individually and in combination.Overall,this research may aid in effective management of coastal wetlands as blue C sinks,emphasizing their significance as essential elements of climate mitigation strategies.

Study and Application of Fuel-breaks in Southwest China

All of the plants can be combusted. The mechanism of forest belts resistance is that the tree specieswerent liable to be burned compared with other plant species. In this paper new concepts on fire resistanttrees and fuel-breaks trees were presented. The fire resistance mechanism includes 3 aspects, fire-resistanttree species, rational construction forest belts and environment. Tree crowns can resist fire forwarding.Forest belts can form the environment, which is not easy to fire, and also make fuels distributed discontinuous.The network of forest belts has large area of conifer forest segregated. The ideal fire resistant tree species hadbetter to embrace some characteristics, such as high fire resistance, rational planting and biological characteristics.