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931.
我国森林公园旅游开发与规划研究综述 总被引:1,自引:0,他引:1
在阅读大量文献资料的基础上,试图从森林公园旅游资源调查与评价、森林公园旅游规划与建设、森林公园旅游产品开发、森林公园旅游资源开发问题与对策、森林公园旅游资源的开发与保护、森林公园景观资产的评估、森林公园旅游解说系统等方面对国内有关森林公园旅游开发与规划的研究进行了系统综述。在此基础上,对中国森林公园旅游开发与规划以后的研究进行了展望。 相似文献
932.
Linyan Zhang Hong Jiang Xiaohua Wei Qiuan Zhu Shirong Liu Pengsen Sun Jingtao Liu 《Journal of the American Water Resources Association》2008,44(5):1154-1163
Abstract: Information on evapotranspiration (ET) can help us understand water balance, particularly in forested watersheds. Previous studies in China show that ET was relatively low (30‐40% of total precipitation) in the Minjiang Valley located in the upper reach of the Yangtze River Basin. However, this conclusion was derived from research on small‐scale watersheds (<100 km2). The objective of this paper was to present ET information on meso‐scale watersheds in the Minjiang Valley. Four meso‐scale watersheds (1,700‐5,600 km2) located in the Minjiang Valley were used to estimate ET using the water balance approach. We first generated forest vegetation variables (coniferous forest percentage, forest cover percentage, and derived forest vegetation index) using remote sensing data. Landsat 5 TM satellite images, acquired on June 26, 1994, were selected for the vegetation classification. Actual annual ET was calculated based on 11‐year estimated precipitation and measured streamflow data (1992‐2002). We also calculated potential ET (PET) using an improved Thornthwaite model for all four watersheds for the period of 1992‐1998. PET can provide additional information about potential capacity of water flux to atmosphere in the region. Seasonal (dry and rainy) PET and ET for all studied watersheds were also estimated for comparison purposes as the water balance approach, at shorter than annual scales, would likely provide inaccurate estimates of ET. The dominant vegetations in the Minjiang Valley were grasslands, conifer forests, and shrub‐lands. Our results confirmed that both ET and PET for three studied meso‐scale watersheds in the Minjiang Valley is relatively low (39.5‐43.8 and 28.2‐47.7% for ET and PET, respectively), with an exception of ET in the Yuzixi watershed being 71.1%. This result is generally consistent with previous research at small watershed scales. Furthermore, the low ET across various scales in the Minjiang Valley may be related to the unique deeply cut valley environment. 相似文献
933.
Background, Aim and Scope
Acid deposition has become a concern in south China in recent years. This phenomenon has increased to a dramatic extent with
the large use of cars and coal- fueled power plants. As a consequence, soils are becoming acidified and their element dynamics
will change. A decrease in the nutrient availability will lead to slower plant growth and maybe to a change in the forest
type with current species being replaced by new ones with less nutrient requirements. Because of these reasons, it is important
to understand how the dynamics of elements will change and what mechanism is part of the process. This knowledge is important
for modeling the acidification process and either finding ways to counter it or to predict its consequences. The primary purpose
of this study was to provide information about how the dynamics of K, Na, Ca, Mg and P are affected by acid deposition in
a typical forest in southern China.
Materials and Methods:
Experimental soils and saplings were collected directly from the monsoon evergreen broad-leaved forest in Dinghushan. All
saplings were transplanted individually into ceramic pots in August 2000 and placed in an open area near their origin site.
Pot soils were treated weekly from October, 2000 to July, 2002 with an acidic solution at pH 3.05, pH 3.52, pH 4.00 or pH
4.40, or with tap water as a control. The concentrations of SO42-, NO3-, K+, Na+, Ca2+, Mg2+ and available P and the pH were
measured in soil and leachate samples taken at different times. The sapling leaves were collected and their element concentrations
were measured at the end of the experiment.
Results:
Concentrations of soil exchangeable Ca and Mg decreased quickly over time, although only Ca showed changes with the acidic
solution treatment and soil exchangeable K was stable because of soil weathering. Leaching of K, Mg and Ca was dependent upon
the treatment acidity. Soil available P decreased slowly without any correlation with the acidity of the treatment. All the
NO3- added by the treatment was taken up by the plants, but the SO42- added accumulated in the soil.
Discussion:
Amongst the plant species, Schima superba was little affected by the treatment, the leaf P content was affected in Acmena
acuminatissima plants and Cryptocarya concinna was the most susceptible species to soil acidification, with a marked decrease
of the leaf K, Ca and Mg concentrations when the treatment acidity increased.
Conclusions:
Simulated acid deposition affected the dynamics of K, Ca and Mg in the monsoon evergreen broad-leaved forest. The dynamics
of Ca in the soil and of K, Mg and Ca in the soil leachates were affected by the acidic solution treatment. If such a soil
acidification occurs, Cryptocarya concinna will be amongst the first affected species, but Schima superba will be able to
sustain a good growth and mineral nutrition.
Recommendations and Perspectives:
Acid deposition will lead to imbalance the nutrient elements in the evergreen broad-leaved forest because of accelerated leaching
losses of soil exchangeable Ca and Mg. Measures should be developed to slow down soil acidification or nutrient decrease. 相似文献
934.
Evaluating Controlling Factors to Ali/(Ca + Mg) Molar Ratio in Acidic Soil Water, Southern and Southwestern China: Multivariate Approach 总被引:2,自引:0,他引:2
Guo JH Zhang XS Vogt RD Xiao JS Zhao DW Xiang RJ Luo JH 《Environmental monitoring and assessment》2007,129(1-3):321-329
Ali/(Ca + Mg) molar ratio in soil water has been used as an indicator to the effects of acid deposition on terrestrial ecosystems.
However, the main factors controlling this ratio have not been well documented in southern and southwestern China. In this
study, we presented the variation in inorganic aluminum (Ali) and Ali/(Ca + Mg) molar ratio in different sites and soil horizons based on two to three years monitoring data, and evaluated the
main factors controlling Ali/(Ca + Mg) molar ratio using principle component analysis (PCA) and partial least square (PLS) regression. Monitoring data
showed although Ali/(Ca + Mg) molar ratios in most soil water were lower than assumed critical 1.0, higher molar ratios were found in some soil
water at TSP and LXH site. Besides acid loading, both soil properties and soil water chemistry affected the value of Ali/(Ca + Mg) molar ratio in soil water. Partial least square (PLS) indicated that they had different relative importance in
different soil horizons. In A-horizon, soil aluminum saturation (AlS) had higher influence on Ali/(Ca + Mg) molar ratio than soil water chemistry did; higher soil aluminum saturation (AlS) led to higher Ali/(Ca + Mg) molar ratio in soil water. In the deeper horizons (i.e., B1-, B2- and BC-horizon), inorganic aluminum (Ali) in soil water had more and more important role in regulating Ali/(Ca + Mg) molar ratio. On regional scale, soil aluminum saturation (AlS) as well as cation exchange capacity (CEC) was the
dominant factor controlling Ali/(Ca + Mg) molar ratio. This should be paid enough attention on when making regional acid rain control policy in China. 相似文献
935.
介孔TiO2纤维的制备及其光催化性能 总被引:3,自引:1,他引:2
采用溶胶-凝胶和水蒸气活化热处理技术制备了介孔TiO2纤维,考察了各种因素对介孔TiO2纤维光催化活性的影响,并对介孔TiO2纤维结构进行了表征。介孔TiO2纤维的最佳制备条件:n(TBOT)∶n(C6H10O3)∶n(H2O)∶n(C3H8O)=1∶0.4∶2.0∶16,搅拌时间80min,Si与Ti的摩尔比为0.15,采用分段程序升温工艺,活化温度为700℃。所得介孔TiO2纤维比表面积为127.7m2/g,最可几孔径为7.3nm,具有极高的热稳定性及抗晶型转变能力,反应时间75min时活性艳红X-3B降解率为99.3%。 相似文献
936.
通过厌氧间歇试验,研究了4种酚类物质在不同浓度下的累积产气量,并将其归纳为两类8种不同降解性影响的典型曲线.试验表明,4种酚类物质中,苯酚和邻甲酚可被厌氧微生物降解,而对甲酚和五氯酚不能被厌氧微生物降解. 相似文献
937.
基于欧盟的物质流分析(MFA)框架,对青岛市城阳区的物质代谢状态和代谢强度进行了系统分析.结果表明:1995─2004年城阳区资源投入量和污染物排放量分别增长3.6和1.8倍,化石燃料和矿物约占资源投入量的50.26%~76.30%,进口资源量所占比例呈逐年增长趋势,经济发展的资源外部依赖性较强.万元GDP资源投入由6.01 t降至3.56 t,万元GDP污染物排放量也降低了63.74%,表明城阳区经济发展的资源利用效率和生态效率已有不同程度的提高,但仍远高于发达国家20世纪末期的水平,因此提高资源生产力和控制污染物排放是实现城阳区可持续发展的必由之路. 相似文献
938.
Aya Yoshida Atsushi Terazono Toshiya Aramaki Keisuke Hanaki 《Journal of Material Cycles and Waste Management》2005,7(1):8-15
China has been the largest importer of secondary materials for recycling from Japan during the past decade. In this study, we analyzed the transfer of major secondary materials (plastic, steel, copper, and aluminum scrap) from Japan to China. We identified specific destinations for secondary materials, and the characteristics of secondary materials transferred to China. The major destination for the transfer of secondary materials to China is Guangdong province and part of the Huadong area (Shanghai, Zhejiang, and Jiangsu). Most scrap metal imported into China is of low quality. The destinations of most high-quality nonferrous scrap, imported as processed goods on consignment or through the transit improvement trade, are the northeast border provinces, especially Xinjiang Uighur province. The coefficients of specialization for Chinese cities were different from those for the provinces. Guangdong shows an average recycling structure for China. The structure gradually changes from south to north. 相似文献
939.
Philip M. Fearnside 《Environmental management》1997,21(4):553-570
940.