晋西北旱坡地枣树蒸腾作用与萎蔫现象研究

以木枣为试材进行枣树蒸腾作用与萎蔫现象研究 ,结果表明 :晋西北黄土丘陵旱坡地枣树叶片在正常年份内的蒸腾速率为 0 .93 μg/ (s· cm2 ) ;枣树的蒸腾系数为3 81 .66,即枣树叶片每制造 1 g干物质需要消耗水分 3 81 .66g。枣树的萎蔫现象是指果实的萎蔫和叶片的萎蔫 ,枣树幼树叶片的永久萎蔫系数为 3 .5%,而枣树大树叶片的永久萎蔫系数应低于 3 .3 6%。果实萎蔫分为暂时萎蔫和永久萎蔫。果实萎蔫时期一般是在气温最高的 7月— 8月份 ,特殊年份可持续至 9月上旬 ,枣果实开始萎蔫时的土壤水分含量在 6%左右。     

河套灌区春小麦高产栽培水氮高效利用研究

在内蒙古河套灌区解放闸灌域沙壕渠实验站,通过田间试验,对节水灌溉模式(拔节+抽穗2水)和常规充分灌溉模式(分蘖+拔节+抽穗+灌浆4水)下,不同施氮量对春小麦产量形成、水分利用和氮素利用等方面进行了研究.结果表明:2水与4水处理间小麦产量及其构成因素均无显著差异,而水分利用效率(WUE)比4水处理提高7.8%.在较低施氮...     

沙枣造林施用保水剂的试验研究

沙枣具有较强的抗旱性能，在干旱浅山区，进行山旱地沙枣造林具有重要的生态价值和经济价值，通过采用保水剂处理沙枣造林试验，可以明显提高沙枣的地径、树高生长，并提高成活率。对于保水剂对沙枣安全越冬，及保水剂持久效果等问题需继续试验观察研究测定。     

Spatiotemporal changes in terrestrial water storage in the Beijing-Tianjin Sandstorm Source Region from GRACE satellites

The Sandstorm Source Control Project in and around the Beijing-Tianjin region was one of the most important ecological projects in China. Terrestrial water storage (TWS) has important impacts on the ecological construction, agriculture, industry, and resident’s lives. Based on the Gravity Recovery and Climate Experiment (GRACE) data, meteorological and Moderate Resolution Imaging Spectroradiometer (MODIS) data, etc., this paper analyzed spatiotemporal characteristics of TWS, groundwater storage, and precipitation, and explored the influencing factors of regional TWS combined with land use and land cover (LULC), social and economic data. The most important results were as follows: (1) From 2003 to 2016, TWS in the Beijing-Tianjin Sandstorm Source Region showed a decreasing trend with a rate of 3.14 mm yr⁻¹. (2) The TWS decline was caused mainly by groundwater overexploitation, but not precipitation variation. (3) Spatiotemporal variations of TWS were related to LULC. The area with the most serious decrease of TWS was mainly located in the southwestern part of the region, where farmland percentage and population density were greater. (4) Reducing the percent of farmland and tree planting, and adding the shrub and grass planting, could be a viable choice for the Beijing-Tianjin Sandstorm Source Control Project. These results provide a scientific basis for regional water resource and ecological management.     

Assessing the effects of vegetation and precipitation on soil erosion in the Three-River Headwaters Region of the Qinghai-Tibet Plateau,China

Soil erosion in the Three-River Headwaters Region (TRHR) of the Qinghai-Tibet Plateau in China has a significant impact on local economic development and ecological environment. Vegetation and precipitation are considered to be the main factors for the variation in soil erosion. However, it is a big challenge to analyze the impacts of precipitation and vegetation respectively as well as their combined effects on soil erosion from the pixel scale. To assess the influences of vegetation and precipitation on the variation of soil erosion from 2005 to 2015, we employed the Revised Universal Soil Loss Equation (RUSLE) model to evaluate soil erosion in the TRHR, and then developed a method using the Logarithmic Mean Divisia Index model (LMDI) which can exponentially decompose the influencing factors, to calculate the contribution values of the vegetation cover factor (C factor) and the rainfall erosivity factor (R factor) to the variation of soil erosion from the pixel scale. In general, soil erosion in the TRHR was alleviated from 2005 to 2015, of which about 54.95% of the area where soil erosion decreased was caused by the combined effects of the C factor and the R factor, and 41.31% was caused by the change in the R factor. There were relatively few areas with increased soil erosion modulus, of which 64.10% of the area where soil erosion increased was caused by the change in the C factor, and 23.88% was caused by the combined effects of the C factor and the R factor. Therefore, the combined effects of the C factor and the R factor were regarded as the main driving force for the decrease of soil erosion, while the C factor was the dominant factor for the increase of soil erosion. The area with decreased soil erosion caused by the C factor (12.10×10³ km²) was larger than the area with increased soil erosion caused by the C factor (8.30×10³ km²), which indicated that vegetation had a positive effect on soil erosion. This study generally put forward a new method for quantitative assessment of the impacts of the influencing factors on soil erosion, and also provided a scientific basis for the regional control of soil erosion.     

不同品种和地区对稻米镉含量与品质的耦合影响

为了研究不同水稻品种在不同种植地区的稻米镉含量及其与品质的关系,以分别种植在湖南长沙和广东惠州的‘齐丰占’、‘湘直粳’、‘玉香油占’等46个不同遗传背景的水稻品种(系)为研究对象,采用原子吸光光谱法测定稻米镉含量和FOSS全自动流动注射仪测定米质各性状指标。结果表明:(1)不同基因型水稻品种的镉积累存在极显著水平的品种间差异,在长沙地区种植稻米平均镉含量大约是惠州地区的两倍。(2)不同水稻品种(系)在惠州地区种植的稻米品质明显优于长沙地区。(3)不同水稻品种(系)在长沙地区种植的精米镉含量与胶稠度、蛋白质含量间具显著相关性;而在惠州地区主要与糙米率、精米率呈显著水平的负相关;与其他米质性状的相关性均未达显著水平。惠州地区稻田环境更利于种植水稻,‘湘晚12选32’、‘湘晚籼12号’、‘湘晚6选31’等为低镉积累品种,可推广;‘佳福占’、‘9311选’、‘R云育90’等镉含量已超过国标,不可作为生产推广品种。     

Incorporating local ecological knowledge into urban riparian restoration in a mountainous region of Southwest China

Modern cities use straightened and concrete watercourses with simple greening for riparian zones, which has been criticised for insensitivity to natural system integrity and cultural identity. This increases the challenge to urban ecologists, landscape designers and managers to conceive innovative and effective design solutions that do not jeopardise hydraulic efficiency yet are culturally acceptable to local communities. This paper introduces the field of local ecological knowledge (LEK) as rich sources of inspiration and design solutions to meet this challenge. LEK refers to knowledge and practices of various local cultures about the relationship of living beings (including humans) with their environments. Wepropose a pragmatic framework that integrates LEK with modern landscape design. It includes steps: (1) investigate existing practices, skills andmeasures relating to LEK; (2) explore how and whereLEKcan inspire or integrate withdesign. Here we propose three aspects for integration in accordance with the nature of landscaping process: overall structure, component and maintenance.(3)evaluate and test the integration in terms of its acceptability by local communities. Taking the riparian revegetation project of Hanfeng Lake Urban Wetland Park (Chongqing Municipality) as an example, we illustrate the utility of this framework. 11 local common practices relating to LEK were identified. According to thethree aspects for integration, alternative design solutions were offered. The survey showed that LEK based designwas more highly valued than other conventional ways in terms of useracceptance. We conclude that LEK provides actionable ecologically sound and culturally desirablesolutions for urbanlandscape. We also recognise that LEK evolveswith changing environments and new harmonious and dynamic human-nature relationships arecontinually re-forming. The process of acquisition and application of LEK could encourage multidisciplinary and synthetic approaches to urban ecosystems. Such adaptability and interdisciplinary engagementare crucial totoday’schanging and complexurban environments.     

1965—2015年庆阳塬区气温和降水极端事件研究分析

为了研究庆阳塬区气温和降水极端事件变化的特点及规律，提供防灾减灾科学依据，利用1965—2015年庆阳塬区西峰站的平均气温、日最高气温、日最低气温、降水等观测资料，应用多种方法和指标进行分析。结果表明：（1）庆阳塬区年平均降水量539 mm，极端降水阈值22.7 mm，极端降水日数4.8天，极端降水强度36.6 mm/d，暴雨32次。（2）年平均气温9.0℃，极端最高气温29.2~36.4℃，极端最低气温-22.6~-11.3℃，夏天日数65.1天，低温日数125.7天，高温31次。（3）年降水量、极端降水量、极端降水日数及强度均呈减少趋势，年最大日降水量呈不显著上升趋势，暴雨变化趋势比较平稳。（4）年平均气温、极端最高气温、极端最低气温、夏天日数均呈上升趋势，低温日数减少趋势与年平均气温、极端最低气温出现增温相对应。（5）年降水量与极端降水量之间，极端降水量与极端降水日数和强度之间均呈线性正相关，极端最低气温的升高、低温日数的减少对平均气温的升高贡献最为显著。     

1961—2010年东北农作区春小麦需水量的时空变化特征

利用东北农作区58个气象站点1961—2010年的逐日气象数据,基于Simulation of Evapotranspiration of Applied Water(SIMETAW)模型分析气候变化背景下东北农作区春小麦生育期内作物需水量(Crop evapotranspiration,ETc)和灌溉需要量(Evapotranspiration of applied water,ETaw),以及典型站点春小麦的灌溉需求指数(Irrigation demand index,IDI)的时空变化特征。结果表明:近50年来,东北农作区日平均温度呈显著上升趋势,平均降水量下降趋势不明显,平均太阳辐射及作物蒸散量呈显著下降趋势。春小麦生育期作物需水量和灌溉需要量呈下降趋势,其分布均表现为西多东少。50年来春小麦作物生育期需水量下降主要集中于松辽及兴安岭南部地区,东部地区变化趋势不明显;生育期灌溉需要量下降集中于松辽及兴安岭地区,三江平原地区略有增加,长白山地区多年保持平稳。     

南方旱地作物栽培模式及发展趋势

该文介绍了20世纪80年代以来,我国南方旱地主要作物栽培模式的演变形式,不同栽培模式的技术要点。根据现代农业发展的迫切需求、中国农村劳动力严重缺乏等现状,解析了当前农村土地流转的实际形式以及取得的部分成绩,展望了南方旱地农业,农村产业发展的方向。为南方旱地农业的发展提供借鉴。