旅游发展中利益相关者环境意识水平分析

环境意识作为一种新的独立意识形态,能够规范社区与社会的生活方式和经济活动方式.因此,旅游发展的生态安全状态取决于直接利益相关者的环境意识水平以及他们之间的相互利益协调关系,主要包括:旅游管理部门、旅游者、旅游企业和当地社区。文中根据环境意识结构,设计了旅游环境意识调查问卷,其主要的指标体系包括:旅游环境知识水平、旅游环境态度、旅游环境评价和旅游环境行为四个方面。并设计了环境意识总体评价模型,以此来计算旅游发展中旅游环境意识水平的综合得分。经过分析得知,旅游管理部门的环境意识水平最高,其次是社区居民,再次是旅游企业,最后是旅游者,而且总体水平都不高。所以,在旅游发展中必须提高各利益相关者的旅游环境意识水平,推动他们自觉参与保护旅游生态环境安全的行动中来。     

A spatially-explicit method to assess the dry deposition of air pollution by urban forests in the city of Florence,Italy

Urban forests (UF) provide a range of important ecosystem services (ES) for human well-being. Relevant ES delivered by UF include urban temperature regulation, runoff mitigation, noise reduction, recreation, and air purification. In this study the potential of air pollution removal by UF in the city of Florence (Italy) was investigated. Two main air pollutants were considered – particulate matter (PM₁₀) and tropospheric ozone (O₃) – with the aim of providing a methodological framework for mapping air pollutant removal by UF and assessing the percent removal of air pollutant.The distribution of UF was mapped by high spatial resolution remote sensing data and classified into seven forest categories. The Leaf Area Index (LAI) was estimated spatially using a regression model between in-field LAI survey and Airborne Laser Scanning data and it was found to be in good linear agreement with estimates from ground-based measurements (R² = 0.88 and RMSE% = 11%). We applied pollution deposition equations by using pollution concentrations measured at urban monitoring stations and then estimated the pollutant removal potential of the UF: annual O₃ and PM₁₀ removal accounted for 77.9 t and 171.3 t, respectively. O₃ and PM₁₀ removal rates by evergreen broadleaves (16.1 and 27.3 g/m²), conifers (10.9 and 28.5 g/m²), and mixed evergreen species (15.8 and 31.7 g/m²) were higher than by deciduous broadleaf stands (4.1 and 10 g/m²). However, deciduous forests exhibited the largest total removal due to the high percentage of tree cover within the city. The present study confirms that UF play an important role in air purification in Mediterranean cities as they can remove monthly up to 5% of O₃ and 13% of PM₁₀.     

Simple method for extracting the seasonal signals of photochemical reflectance index and normalized difference vegetation index measured using a spectral reflectance sensor

A spectral reflectance sensor(SRS) fixed on the near-surface ground was developed to support the continuous monitoring of vegetation indices such as the normalized difference vegetation index(NDVI) and photochemical reflectance index(PRI). NDVI is useful for indicating crop growth/phenology, whereas PRI was developed for observing physiological conditions. Thus, the seasonal change patterns of NDVI and PRI are two valuable pieces of information in a crop-monitoring system. However, capturing the seasonal patterns is considered challenging because the vegetation index values estimated by the reflection from vegetation are often governed by meteorological conditions, such as solar irradiance and precipitation. Further, unlike growth/phenology, the physiological condition has diurnal changes as well as seasonal characteristics. This study proposed a novel filtering method for extracting the seasonal signals of SRS-based NDVI and PRI in paddy rice, barley, and garlic. First, the measurement accuracy of SRSs was compared with handheld spectrometers, and the R~2 values between the two devices were 0.96 and 0.81 for NDVI and PRI, respectively. Second, the experimental study of threshold criteria with respect to meteorological variables(i.e., insolation, cloudiness, sunshine duration, and precipitation) was conducted, and sunshine duration was the most useful one for excluding distorted values of the vegetation indices. After data processing based on sunshine duration, the R2 values between the measured vegetation indices and the extracted seasonal signals of vegetation indices increased by approximately 0.002–0.004(NDVI) and 0.065–0.298(PRI) on the three crops, and the seasonal signals of vegetation indices became noticeably improved. This method will contribute to an agricultural monitoring system by identifying the seasonal changes in crop growth and physiological conditions.     

气候变化下西北太平洋大海洋生态系海表面温度特征分析

黄鳍金枪鱼 (Thunnus albacares) 为高度洄游的大洋性鱼类,有较高的生态和经济价值,中西太平洋 (Western and Central Pacific Ocean, WCPO) 是全球金枪鱼捕捞产量最高的海区。为了解和预测中西太平洋黄鳍金枪鱼不同渔业对气候变化的反应,根据1990—2020年世界各国在中西太平洋的围网和延绳钓作业以及海洋尼诺指数 (Oceanic Niño index, ONI) 数据,分析了常规自回归积分滑动平均模型 (Autoregressive Integrated Moving Average Model, ARIMA) 和加入ONI标准差为协变量的动态ARIMA模型在渔业资源量研究中的适用性,以及ONI对中西太平洋黄鳍金枪鱼年际单位捕捞努力量渔获量 (Catch per unit effort, CPUE) 的影响。结果表明：1) 常规ARIMA模型能够充分考虑中西太平洋黄鳍金枪鱼年CPUE的变化特征,可用于黄鳍金枪鱼年CPUE的长期拟合;2) 相比常规ARIMA模型,动态ARIMA模型的拟合度更好,拟合值和真实值的相关性更高,同时平均绝对误差、均方根误差更小;3) ONI对中西太平洋赤道南北海域黄鳍金枪鱼的年CPUE影响不同,相对而言,在赤道以北,ONI的影响因素更关键,模型的拟合度更高;4) ONI对中西太平洋不同渔业的黄鳍金枪鱼的年CPUE影响有差别,对中西太平洋黄鳍金枪鱼延绳钓渔业存在滞后1~2年的影响,而在强厄尔尼诺和强拉尼娜现象时,对围网渔业的影响速度较快,不存在滞后。     

Determination and Analysis of Heavy Metal Content in the Soil from Beef Cattle Farms in Three Regions of Xinjiang

In order to study and evaluate the feeding environment of the beef cattle farms in Xinjiang, the contents of heavy mentals in the soil from 8 beef cattle farms in Xinjiang Aksu, Yili and Tacheng regions were tested according to the Field of Livestock and Poultry Environment Quality Standard (NY/T 388—1999).The atomic absorption spectroscopic method was used to determine the contents of As, Hg, Pb, Cd, and Cr.The mean contents of As, Hg, Pb, Cd, and Cr in 8 beef cattle farms soil were 0.389, 0.568, 22.708, 0.573 and 149.449 mg/kg, respectively, and they were all below the upper limit of NY/T 388—1999.The comprehensive heavy metal pollution index of 8 beef cattle farms were 0.577 to 0.994, and the index were 0.7 to 1 of two observation points in Yili and one observation point in Tacheng.The soil environment quality of these 3 farms were at the level of slight cleaning.The comprehensive heavy metal pollution index of other five observation points were ≤0.7, the soil environment was in a clean level.The soil environment of beef cattle farms in these three regions conformed to the standards of livestock for environment quality and safe products.     

Response of labile organic C and N pools to plastic film removal from semiarid farmland soil

To examine the effects of plastic film removal on grain yield and soil organic matter (SOM), a spring maize (Zea may L.) field experiment was conducted for 5 yr at Changwu Agricultural and Ecological Experimental Station of Northwest China. Compared with traditional plastic film mulching during entire growing stages (FM), plastic film removal at the silking stage (RM) resulted in a 6.3% higher average maize yield. Under the RM treatment, soil organic carbon and total nitrogen significantly increased after the 5‐yr cultivation in the 0‐ to 20‐cm layer. Significant increases in extractable organic C (EOC), KMnO₄‐oxidizable C (KMnO₄‐C) and C management index (CMI) in the 0‐ to 20‐cm layer, and light fraction organic C and EOC in the 20‐ to 40‐cm layer were observed in response to plastic film removal after the 1‐yr treatment; the responses were more significant after 5 yr. Under the RM treatment, significant increases in microbial biomass C, light fraction organic N, extractable organic N, KMnO₄‐C and CMI were also observed after five years in the 20‐ to 40‐cm layer. Moreover, KMnO₄‐C and EOC were much more sensitive than other labile SOM fractions to the application of RM, even after only 1 yr of cultivation. Therefore, compared with mulching for the whole growing season, plastic film removal at the maize silking stage is an effective option for increasing yields and enhancing SOM concentration and soil sustainability in the regions with semiarid monsoon climates that have sufficient rainfall during maize reproductive stages.     

东北地区春玉米临界氮浓度稀释曲线的建立和验证

过量施氮是目前玉米栽培中存在的普遍现象,基于临界氮浓度稀释曲线计算得出的氮营养指数是诊断氮营养丰缺的重要手段。基于东北地区4个生态点的试验数据,构建了东北地区春玉米临界氮稀释曲线,并在此基础上建立了氮营养指数模型和需氮量模型,结果表明,东北地区春玉米地上部临界氮浓度与生物量符合幂函数关系。利用独立试验资料对建立的临界氮浓度稀释曲线进行检验,发现基于临界氮浓度稀释模型计算的氮营养指数可以准确诊断玉米植株的氮营养状况,并计算出实时的氮素需求量。该研究建立的东北地区春玉米临界氮稀释模型可以为该地区春玉米的氮营养诊断和动态调控提供较好的理论和技术指导。     

Effect Of Replacing Fish Meal With Blood Meal On Chemical Composition Of Supplement For Nile Tilapia (Oreochromis Niloticus)

The objective of the work was to evaluate the effect on the nutrient content of replacing fish meal (FM) with blood meal (BM) in fish supplement. Three isonitrogenous diets (35% crude protein) were formulated using FM as the main source of animal protein (BM0); 50% replacement of FM with blood meal (BM50); or 100% replacement of FM with BM (BM100). The chemical composition (ash, crude protein, crude fat and crude fibre) and amino acid composition were determined. Replacement of FM with BM did not affect the proximate composition of the diet apart from ash content which decreased with the level of substitution. Substituting fish meal with blood meal reduced the levels of methionine, lysine, isoleucine, leucine, proline, valine and increased the levels of arginine, phenylanine and alanine in the diet. Amino acid indices revealed that BM0 had more amino acids with the highest chemical scores followed by BM50 and BM100. In all the diets, methionine was the most limiting amino acid. The essential amino acid index of the diets reduced with the level of replacement of FM (0.94, 0.88 and 0.77). The study showed substitution of up to 50% FM with BM gave a useful protein diet and 100% gave almost a poor protein diet.     

非线性、分形与期锌市场价格

从非线性角度研究期锌市场，运用R/S分析法对期锌市场进行分析，发现期锌市场的Hurst指数为0.6183,其价格收益率序列是分维时间序列，具有分形结构，维数为1.6174。期锌市场的平均周期长度为176天，具有强持续性和相关性。关联系数为19.47%，远远大于国外相关市场。在风险方面，期锌市场的风险比期铜市场的要小，而比股票市场的风险要大。     

不同密度紧凑型油菜的源库特征及与收获指数的相关研究

旨在为油菜株型育种和机械化栽培提供理论和技术依据。选用3个不同类型的紧凑型油菜常规品种,以松散型油菜杂交种‘秦优7号’为对照,研究了在15万、30万、45万、60万、75万、90万株/hm²密度下各品系的库源特征及其与收获指数的关系。结果表明,紧凑型油菜单株在不同密度下的库源特征与对照松散型相同,单株根、茎、枝、壳干重,角粒数和单株角果数随种植密度的增加而降低,且低密度显著高于高密度;千粒重随密度的变化不大。紧凑型油菜的生物学产量和经济产量随种植密度的增加而增加,松散型油菜随种植密度的增加而下降。说明紧凑型油菜适宜密植和机械化收获。收获指数对密度的响应在两类型品种表现一致,最低密度15万株/hm²增加到30万株/hm²时达到峰值,以后随着种植密度的继续增加而降低。收获指数与茎+枝+壳干重之和,与库性状角粒数、角果数、千粒重、单株产量,与库源关系的粒根比、粒茎比、粒枝比、粒壳比显著正相关,说明要提高收获指数不仅要扩“源”增“库”,还要协调库源的合理分配比例。