云南不同气候带农业气候资源变化特征研究

为分析全省平均以及各气候带光能、热量、水分资源的时空变化特征,使用云南115站及6个气候带代表站1961—2018年的气候要素计算各地农业气候资源统计量。结果表明,光能资源变化以减少趋势为主,出现显著突变,各气候带太阳辐射变化可能会引起云南太阳辐射高低值中心发生变化,2009年以来辐射明显增加可能会导致太阳辐射出现新的变化趋势和突变点;热量资源一致显著增加,喜凉及喜温作物的活动积温、积温持续时间及无霜期长度均显著增加,并且呈现初日提前、终日推后的趋势,对作物生长有利;水分资源总体呈现减少趋势,尤其21世纪以来下降趋势明显,亚热带地区暖干化现象突出,干旱风险等级较高。     

青冈栎林分空间结构对林下更新的影响

林分空间结构会显著影响其林下幼树更新。为明确其影响林下幼树更新的关键因子,以湖南省青羊湖国有林场青冈栎林天然次生林为研究对象,测量幼树株数密度、树高、地径和冠幅,计算混交度、大小比数、开敞度指数以及聚集指数代表林分空间结构,评价林下幼树更新情况,并用灰色关联度分析方法探究两者间的相关关系。结果表明,青羊湖国有林场13块青冈栎林样地林下更新幼树有6种,分属于4科5属,分别是青冈栎、苦槠、多脉青冈、南酸枣、黄檀、马尾松,青冈栎在更新幼树中占明显优势,是优势树种,幼树重要值为63.09%。青冈栎林各林分空间结构指数与林下更新指数均大于0.5,关联度较高,综合所有林分空间结构指数对林下更新指数关联度的均值来看,对林下更新的影响由大到小为大小比数>开敞度>聚集指数>混交度,大小比数对青冈栎林下更新影响最为显著。在促进青冈栎天然次生林林下更新时,应以调整林木大小分化程度为主,综合考虑林木空间分布格局的调整方案。     

京西稻的百年传承与发展

京西稻是清康熙、雍正、乾隆等亲自选育的优良品种,在与紫禁城并重的“三山五园”政治中心内外种植,具有多重价值属性,属于皇家御稻。从2000年起,基于北京水资源匮乏等原因,京西稻种植面积大幅度降至134 hm²左右,处于濒危状态。在保护传承过程中,京西稻入选中国重要农业文化遗产目录。在新修订的《北京历史文化名城保护条例》中,又将京西稻列入遗产保护目录。在海淀区,京西稻已经深入公园、学校、社区、酒店等地,在教育文化中发挥着农业以外的作用。     

鹿肚耳与3种木耳的营养价值评价

综述皱木耳Auricularia delicata新品种"鹿肚耳"的形态特征和食用特点,测定其与黑木耳、毛木耳、毛木耳白色变种"玉木耳"人工栽培子实体的基本营养成分、矿质元素含量和氨基酸组成,评价其营养价值。结果表明:鹿肚耳热量235 kJ/100g、蛋白质7.21 g/100g、脂肪1.5 g/100g、碳水化合物48.4 g/100g、总膳食纤维29.3g/100g,含有5种常量元素、5种必需微量元素,其中,硒元素含量是黑木耳的4.6倍;含有人体所需的8种必需氨基酸,氨基酸化学评分(CS)和氨基酸评分(ASS)分别为12和18.86,色氨酸为其限制性氨基酸;蛋白质综合评价低于其他3种木耳。     

基于遥感数据的大尺度区域水田空间格局及生态服务价值变化分析

受经济和气候驱动，长江经济带水田空间格局发生了显著变化，影响区域粮食安全与生态安全。本研究基于1990-2015年土地利用遥感监测数据，利用GIS的空间分析功能，探究长江经济带水田空间格局动态变化特征，采用当量因子法计算生态系统服务价值（ESV），分析了水田变化的综合影响。结果表明：1）1990-2015年长江经济带水田规模持续缩减，共减少了17390km²，减幅呈增长态势具有显著地域差异，长江中上游与下游的水田减幅相差约为9.56%。其中下游减幅较大，水田占区域比例随之降低，中上游恰好相反。2）由于经济建设及水产养殖的发展，水田主要转化为建设用地和水系，水田主要由水系、旱地和湿地等转化而来。长江三角洲城市群、长江中游及成渝城市群的水田变化最为剧烈，建设用地侵占水田扩张的现象分布广泛，水田转为水系主要在两湖平原局部地区。3）水田与其他生态系统的转化对ESV是正影响，水田转为水系对此贡献最大，其转化规模决定了不同时期ESV净增量的大小，水系转化为水田损失的价值最多，建设用地侵占水田次之。不同市域的水田变化情况不一致，因此ESV增减情况具有明显差异。4）生态系统服务中水文调节、水资源供给增强的同时，食物生产、气体调节受到严重损害，与水资源规模扩大和水田资源大量流失有直接关系。研究结果有助于揭示长江流域水田的时空变化过程及其对各项生态系统服务的影响，可为区域土地利用规划、农业政策与生态可持续发展提供理论支持。     

车载智能土壤采样系统设计与试验

针对传统土壤样本采集操作复杂、劳动强度大、采集精度低和缺乏信息化管理的问题，设计了一种车载智能土壤采样系统。该系统安装于无人驾驶采样车上，系统包括土壤样本自动采集装置和电气控制系统。对系统整个工作过程进行分析，确定了各关键机构及控制硬件的主要工作参数。电气控制系统以运动控制器为控制核心，土壤样本自动采集装置对不同深度范围的土样进行采集，并按地理位置信息分类收集，通过RFID读写器将GPS系统定位所解算的目标采样点的经纬度地理信息和采样深度等信息写入收集土样采样筒底部的电子标签中。性能试验表明，安装于无人驾驶采样车的车载智能土壤采样系统工作运行稳定、可靠，能够对农耕层0~200mm任意深度范围的土壤进行自动分层采样，效率高、精度高、全程自动化，能够按照位置信息进行分类管理，较好地满足了智能化高质量采集土样的需求。     

食用菌创意景观设计

通过对食用菌创意景观设计进行研究,分析具体的设计原则和设计方法,在食用菌创意景观打造过程中融入艺术技巧和文化特色,营造独特的食用菌旅游观光资源,创造更多农业生产附加价值。     

食用菌内源脂肪酸的研究

食用菌富含膳食纤维、矿物质、微量元素、维生素和多种氨基酸,是多功能理想食物。尽管食用菌脂类物质含量较低,但包含人类必需的不饱和脂肪酸,如亚油酸、油酸和亚麻酸等。通过对食用菌脂类物质研究成果进行总结,尤其是不饱和脂肪酸种类、含量及其开发利用,以期为食用菌的资源开发提供参考。     

Substrate composition determines emergence success and development of European nase larvae (Chondrostoma nasus L.)

European nase (Chondrostoma nasus) is a specialist riverine fish, characterised by a complex life cycle making it vulnerable to habitat degradation. Recent findings indicate that, analogously to salmonids, the interstitial zone quality may pose a serious bottleneck for successful recruitment of this species. In this study, nase eggs were exposed to different substrate qualities. First, standardised substrate mixtures with differing fine sediment additions were used. Second, we tested different homogenous gravel fractions for their influence on egg development and emergence success. In both setups, substrate composition significantly affected emergence success, timing of emergence and larvae size at emergence. In the substrate mixtures, emergence was most successful in substratum with no fine sediment addition (98%) and decreased to 55% in substratum with 20% fine sediment addition. Emergence was most successful in the coarsest fraction (93%) and decreased to 47% in the finest fraction. Over all treatments, the time between hatching and emergence from substrate differed by up to 156 degree days, thereby indicating that free embryos of nase use the shelter of the interstitial zone for early ontogeny. These results suggest that a loose and porous stream bed can positively contribute to the development success of eggs and larvae and thereby potentially improve the recruitment of nase populations. It is thus important to consider the substrate and interstitial conditions in the conservation and restoration management of this rheophilic cyprinid.     

Landscape pattern changes over 25 years across a hotspot zone in southern Brazil

Forest fragmentation caused by human activities has many implications for natural landscapes, such as habitat reduction and the loss of biodiversity. This study investigated the temporal fragmentation process of forest remnants in a strongly agro-industrialised region in southern Brazil over 25 years. The studied watershed area hosts two important typologies of the Atlantic Forest biome as well as Quaternary remnants of the Brazilian Savanna biome, which are considered hotspots of biodiversity and reflect the intense process of forest fragmentation caused by Brazilian urban and agro-industrial development. Thus, studies encompassing multitemporal scales are paramount to understanding changes in forest patterns and are fundamental for trend predictions of landscape dynamics. To perform the calculation of the mean normalised difference vegetation index, Landsat satellite images from 1991 to 2016 were processed using SPRING® software. Subsequently, FRAGSTATS® software was used to calculate landscape metrics. A reduction in the number of forest fragments since 1991 was observed, with a maximum amount of 5 243 fragments in 1993 that declined to 4 015 fragments in 2016. Although the number of fragments in the watershed decreased, the mean area increased by 72.9% and the mean of the shape index increased from 1.3 in 1991 to 1.5 in 2016. In addition, there was a 64.7% increase in the edge density and a reduction of 35.6 m in the isolation between the nearest neighbours. The degree of isolation of the fragments underwent a process of expansion and reduction when compared to 1991, presenting results that support the hypothesis that the Atlantic Forest is in a process of stabilisation and forest restoration.