Quantifying the influence of geography and environment on the northeast Atlantic mackerel spawning distribution

Mackerel (Scomber scombrus) in the northeast Atlantic have shown changes in distribution at certain times of the year, which have impacted their exploitation and management. In this study, mackerel spawning habitat over 21 recent years was characterised using generalised additive modelling, based on spatial egg density data collected every third year during targeted ichthyoplankton surveys. Mackerel spawning distribution was found to depend primarily on geographical variables (coordinates and bottom depth), with preferred spawning locations on the shelf‐edge from the north of the Iberian peninsula to the west of Scotland, with a maximum west of Ireland. Environmental drivers had a lesser influence on egg distribution. Dome shaped relationships were found with temperature and mixed layer depth, with respective optimum at 13°C and around –300 m. The model was used to reconstruct maps of the potential habitat (areas where conditions were suitable, but not necessarily used, for spawning). Little changes were observed over the years in the potential habitat, suggesting that the expansion of the egg distribution (realised habitat) was not triggered by changes in the environmental variables investigated. Little evidence was found for density‐dependent habitat selection. There was a tendency for mackerel to make more use of areas of lesser suitability in years with large stock size (1992 and 2010). This pattern, however, broke down in 2013, when stock size was the highest, as spawning occurred very south and concentrated in the most suitable habitat.     

几个绿化树种对大气中若干元素作用规律的研究

通过对油松、雪松、云杉、水杉、毛白杨等５个树种穿透降雨的研究得出：不同树种对大气中各元素的吸附聚集能力不同。根据综合评价,各树种对ＮＯ３－－Ｎ、ＮＨ４＋－Ｎ、ＰＯ４３－、Ｋ、Ｎａ、Ｃａ、Ｍｇ、Ｚｎ、Ｍｎ、Ｃｕ、Ｐｂ、Ｃｄ的综合吸附能力为：雪松＞云杉＞油松＞毛白杨＞水杉。     

基于限制性因子法的农用地适宜性评价研究——以石羊河流域为例

为开展农用地适宜性评价,利用文献计量法,聚焦土地自然属性,基于气候、土壤、地形、水文等自然地理条件,梳理农用地适宜性影响因素,选取12个指标构建土地宜耕、宜园、宜林、宜草性评价体系。基于限制性因子法与1OAO原则筛选不适宜区,针对适宜区利用综合评价法考虑适宜程度,最终形成农用地适宜性评价标准,并以2020年石羊河流域为实证区开展验证。结果表明：2020年石羊河流域内仅有2.69%的土地属于耕地适宜区,42.96%不适宜发展耕地;园地适宜区有17.08%,不适宜区有19.12%;林地适宜区有10.27%,不适宜区有6.17%;研究区域内无草地不适宜区,适宜区有12.93%。本研究根据2020年研究区土地覆被现状与2010—2020年农用地转化等实际情况,验证上述评价结果是否合理,结果表明仅存在3.76%的耕地分布在耕地不适宜地区、林地不适宜区没有林地分布,农用地转入和转出也主要分布于一般适宜区和适宜区,基本上符合因地制宜发展,证实了评价指标体系及评价标准的合理性与可行性。因此,利用限制性因子法开展适宜性评价贴合实际,能够为未来农业生产空间布局提供支撑。     

Predicting the current and future suitable habitat distributions of the anchovy (Engraulis ringens) using the Maxent model in the coastal areas off central‐northern Chile

An assessment of climate change impacts on the habitat suitability of fish species is an important tool to improve the understanding and decision‐making needed to reduce potential climate change effects based on the observed relationships of biological responses and environmental conditions. In this study, we use historical (2010–2015) environmental sea surface temperature (SST), upwelling index (UI), chlorophyll‐a (Chl‐a) and biological (i.e., anchovy adults acoustic presence) data (i.e., Maxent) to determine anchovy habitat suitability in the coastal areas off central‐northern (25°S–32°S) Chile. Using geographic information systems (GIS), the model was forced by changes in regionalized SST, UI and Chl‐a as projected by IPCC models under the RPC (i.e., RCP2.6, RCP4.5, RCP6.0 and RCP8.5) emissions scenarios for the simulation period 2015–2050. The model simulates, for all RCP scenarios, negative responses in anchovy presence, reflecting the predicted changes in environmental variables, dominated by a future positive (warming) change in SST and UI, and a decrease in chlorophyll‐a (i.e., phytoplankton biomass). The model predicts negative changes in habitat suitability in coastal areas from north of Taltal (25°S) to south of Caldera (27°45′S) and in Coquimbo littoral zone (29°–30°12′S). The habitat suitability models and climate change predictions identified in this study may provide a scientific basis for the development of management measures for anchovy fisheries in the coastal areas of the South American coast and other parts of the world.     

基于GIS的咸阳石榴种植气候适宜性精细化区划

研究咸阳石榴种植的气候适宜性,充分利用气候资源,找出咸阳石榴种植的适宜区域。利用咸阳12个国家气候观测站1988—2017年最新气象观测资料,采用GIS技术对咸阳石榴栽培进行气候适宜性精细化区划,以期为咸阳石榴生产及农业结构调整提供科学依据。通过分析影响生长和产量的主要气候因子,筛选出咸阳石榴从现蕾至果实成熟需≥10℃的有效积温、年生长期内需≥10℃的有效积温、年日照时数、9月日照时数、7—9月降水量、日平均气温18~21℃时的日较差、年极端最低气温和旬极端最低气温等8个气候适宜性精细化区划指标。评估发现石榴种植优质区占咸阳市面积的14.9%,主要分布在三原、泾阳大部、渭城区西北部、礼泉东部、乾县北部;适宜区占21.3%,分布在兴平市、秦都区、渭城区、礼泉县南部、乾县南部及武功北部台塬区;劣质区占16.6%;不适区占47.2%。咸阳旱腰带以南除武功外都是石榴种植适宜区,该区域光、热、水气候资源满足石榴优质生产所需的全部气象因子,可以大力发展石榴栽培。     

中国农作物气候适宜性研究进展

探讨中国农作物气候适宜性研究现状,为更好地利用气候资源,以及为农作物种植方案和保护措施的制定提供理论依据。本研究总结了目前农作物气候适宜性研究的常用方法,讨论了各方法的原理、优缺点和适用范围,并在此基础上综述了中国水稻、小麦、玉米、棉花、烟草等5种农作物气候适宜性的研究进展。结果发现,中国农作物气候适宜性研究已逐渐深入,在充分利用气候资源、合理安排生产措施等方面发挥重要作用。MAXENT模型、GIS技术、积分回归法、层次分析法等技术各有优缺点,现有方法的综合运用及新技术的不断完善将为农作物气候适宜性研究提供新思路。     

Land suitability evaluation using image processing based on determination of soil texture–structure and soil features

Land evaluation is the process of land performance predictions over time based on land uses and soil features. Traditional methods in determining soil features are proved to be time-consuming and costly. Therefore, in order to overcome these limitations, a simpler automated method using the image segmentation was developed in this study. The method was designed by integrating dynamic region merging and genetic algorithm. An area index was calculated for each soil profile using the automated method. It was used to present the amount of soil coarse particles and thereupon to determine the rating value of text-structure. Using the method, the mean intersection over union of above 0.7 was obtained for detecting the coarse particles which confirms its suitability. Data analysis showed that (a) compared to the Storie-land index (R² = 0.71), the Square root-land index was more correlated to the harvest index (R² = 0.73), and (b) comparing to manual methods, not only the automated text-structure had a higher correlation with the harvest index (R² = 0.64) but also it decreased the determination time (>3.75 times). Furthermore, among the models developed by response surface methodology for estimation of soil features, the developed model for estimation of soil lime showed the highest accuracy (R² = 0.89). In conclusion, since the developed method is more accurate, more economic and faster than the usual manual methods, it can be widely used in land suitability evaluation.     

基于栖息地适宜指数的浙江南部近海黄鲫最适栖息地分布

根据2016-2018年4个季节的浙江南部近海黄鲫（Setipinna taty）的调查数据与水温、水深和盐度等水文数据构建栖息地适宜性指数（habitat suitability index，HSI）模型，探究黄鲫的适宜栖息地空间分布特征，预测最适宜栖息地分布。结果显示，黄鲫最适栖息水温为11.2~33.6℃，最适水深为19~46.6 m，最适盐度为27.8~33.2。通过交叉验证发现，基于几何平均模型（geometric mean model，GMM）拟合的栖息地适宜性指数模型精确度较高。最优模型预测结果显示，黄鲫的最适栖息地分布存在一定季节变化，全年HSI高值区出现在春季和夏季，其次为冬季和秋季。春季适宜性较高的栖息地集中在28°N以南、121.5°E以西，夏季分布在27.5°N~28.5°N、122°E以东，秋季分布在27.5°N~29°N、122.5°E以西和27.5°N以南、121.33°E以西两个区域，冬季分布在122.5°E以西。黄鲫是浙江南部近海重要的渔业种类，本研究通过探索黄鲫的栖息地分布和变化，旨在为黄鲫资源的变化预测与养护策略提供科学证据。     

北京山桃开花期变化及其气候影响因子分析

为了给植被开花期预报和气候变化的生态影响评估提供科学依据,笔者利用1951—2004年北京颐和园山桃开花期观测资料,分析山桃开花期年际、年代际变化和影响其的气候因子。结果表明:山桃多年平均开花期为3月26日,年际间呈显著提前趋势。山桃开花期的转折点在1980s,1980s后呈显著提前趋势(P<0.01),较1950s—1970s平均提前6天。山桃10年平均、最晚、最早开花期均显著提前,尤其是2000年以后山桃的平均、最晚、最早开花期,较1951—1990年分别提前14天、14天、16天。影响山桃开花期时间最主要的是从当年1月1日到山桃开花期的平均气温。1980s开始影响山桃开花期显著提前的主要气候因子是时间段内（冬、春季）平均气温的升高。     

基于DEM的四平市农用土地适宜性评价

将四平市选为研究区域，根据有关文献，对适宜性评价因子进行选取以及确定其权重，再将 其分为四个等级。基于ArcGis 的分析识别模版，按照权重值大小对各评价因子进行叠加分析处理。 研究结果显示，Ⅰ级适宜性所占比例最大，近乎研究区面积的半数，为41.13%；Ⅱ级适宜性位居次席， 占总面积的29.89%；这表明四平市内大部分区域是适合进行农业生产的。Ⅲ级的面积为2927km2，Ⅳ 级面积为1223km2。Ⅳ级，也就是不适宜进行农牧生产的区域大多分布在四平市的东部及南部，要尽 量避免在此耕作。又从自然和人文两个方