河西内陆河流域生态问题及其保护对策

概述了近代河西内陆河流域生态研究成果、流域构成特点和河西地区环境状况,分析了河西内陆河流域存在的生态问题,并从节水农业和水权制度改革、城镇化建设、植被保护、生态用水管理、环境污染的治理等5个方面提出了生态保护对策。     

三北地区内陆盐水的轮虫

1990～1991年间在三北地区盐度0.5～214 g/L的28个内陆水体采集了浮游轮虫水样。共检出59种轮虫。根据出现率和平均密度,下列13种是所调查盐水轮虫区系的主要种类:褶皱臂尾轮虫、角突臂尾轮虫、壶状臂尾轮虫、变异臂尾轮虫、盖氏晶囊轮虫、矩形龟甲轮虫、螺形甲龟轮虫、爱德里亚狭甲轮虫、方尖削叶轮虫、一种单趾轮虫、针簇多肢轮虫、长三肢轮虫和环顶巨腕轮虫。文中讨论了内陆盐水轮虫的种类组成、分布和盐度耐性,以及盐度、碱度、pH、离子系数与种类多样性之间的关系等问题。     

中国北方盐碱水域中的底栖动物

1975～ 1 994年对山西省、河北省、内蒙古自治区和宁夏回族自治区的 2 6个盐碱水域 (盐度 0 5 8～ 1 6 3 0、pH 8 46～ 1 0 1 0 ) ,进行了 92个点的采集。共见到底栖动物 1 0 3种 ,分别隶属于环节动物、软体动物、昆虫类等 1 5个目。其中摇蚊科幼虫有 1 1个属、 48个种。其余为蠓蚊科幼虫、颤蚓科、锥实螺科、扁卷螺科、科、伪蜓科、划蝽科、牙虫科、叶科等种类。分析结果表明 ,所有水域的共同特点是以摇蚊幼虫为优势种群 ,其中花纹前突摇蚊幼虫和羽摇蚊幼虫出现率最高 ,均为 3 0 8%,其次为穴居摇蚊幼虫 ,出现率为 2 6 9%。其它底栖动物如鞘翅目牙虫科幼虫和寡毛纲颤蚓的出现率均为2 3 1 %。对水体主成分的水质分析结果表明 ,决定底栖动物分布和种数的主要因素是与总硬度、盐度和总碱度相关的水化学特征 ,其中底栖动物种数与总碱度呈显著的负相关关系 (R2 =- 0 3 4 2 ,n =2 6 ,P <0 0 5 )。     

近30年来城市化进程对北京区域气温的影响

分析了20世纪70年代以来北京市气温指数的变化规律,发现其与城市化进程有良好对应关系。并应用主成分分析方法,将影响北京城区及郊县各站气温变化的因子分为区域因子及局地因子。计算表明,城市化带来的热岛效应是导致局地增暖的主要因子,占总增暖比重的47.5%～61.2%。在众多表征城市发展的指标中,气温与人口总量的相关性最好。以上结果有助于深入探讨城市化对区域气候的影响机制。     

张掖黑河灌区苜蓿高效灌溉模式研究

通过对黑河流域大满灌区灌溉试验,测定了不同生育年龄甘农3号苜蓿Medecago sativacv.GannongNo.3地上生物量,经统计分析建立了苜蓿地上生物量年际动态和不同生育年内各茬间动态变化规律,结果表明,不同年际间各茬产量在不同水分处理下水分利用效率存在明显差异。不同水分处理下产量的变化呈高-低-高的“S”型变化,确定了苜蓿地的高效灌溉时期为现蕾-开花期,优化灌溉定额为520 mm,为苜蓿高产节水灌溉模式提供了理论依据。     

湿地与我国内陆城市的可持续发展

在我国,内陆城市的城市发展水平和经济发展水平都相对落后,因此我国内陆城市的可持续发展是关系到整个国家能否高速、健康发展的决定性因素。湿地是城市生态环境和城市生态支持系统的重要组成部分,城市中以自然景观为主的公共开放空间。本文通过对城市湿地和城市周边湿地功能作用的分析,指出湿地可以为解决我国内陆城市的生态环境问题,实现城市可持续发展,提供基础条件和生态保障。对我国生态城市的发展和建设具有借鉴意义。     

西北内陆早熟陆地棉品种的综合评价及育种演化

【目的】综合评价近30年西北内陆棉区审定的早熟陆地棉品种,阐述该区域育成品种主要性状的育种演变规律,为西北内陆棉花新品种选育和主栽品种推荐提供参考依据。【方法】2020年和2021年分别在甘肃敦煌和新疆石河子对110个1988—2021年西北内陆棉区审定的早熟陆地棉品种与早熟、产量、纤维品质和株型相关的12个主要性状的表型进行鉴定;利用聚类分析、相关性分析和主成分分析等方法,对品种表型特征进行综合评分,筛选优良品种,并对其主要性状进行育种演化分析。【结果】110个早熟陆地棉参试品种的12个主要性状表型值分布范围较大,变异系数由大到小依次为：果枝长度>单株结铃数>吐絮率>单铃重>马克隆值>纤维强度>衣分>纤维长度>开花时间>果枝夹角>伸长率>整齐度。通过聚类分析将110个早熟陆地棉品种分为Ⅰ、Ⅱ、Ⅲ和Ⅳ4个类群,它们分别为优良纤维品质、早熟、松散株型和高产的品种类群。相关性分析表明,早熟性与产量和纤维品质相关性状均呈负相关,产量构成性状与纤维品质性状呈正相关,且多数性状之间达显著或极显著水平。利用主成分分析将12个主要性状...     

Effects of salinity on growth characteristics and osmoregulation of juvenile cobia,Rachycentron canadum (Linnaeus 1766), reared in potassium‐amended inland saline groundwater

The suitability of inland saline groundwater as a medium to culture juvenile cobia, Rachycentron canadum, was assessed. In the first experiment, juvenile cobia stocked in raw (unamended) saline groundwater at salinities of 5, 10, and 15 g/L exhibited complete mortality after 108, 176, and 195 hr, respectively. The second experiment evaluated the rearing of juvenile cobia (mean weight ~9.23 ± 0.12 g) in potassium (K⁺)‐amended saline groundwater (100% K⁺ fortified) and reconstituted seawater at salinities of 5, 10, and 15 g/L to assess growth and osmoregulation in distinct culture media. Following 60 days of culture, all fish survived the experimental period. Final mean bodyweight of cobia reared in K⁺‐amended saline groundwater (103.2–115.8 g) and seawater (111.2–113.8 g) of different salinities did not vary significantly (p > .05). No differences (p > .05) were observed in specific growth rate, weight gain (%), and feed conversion ratio between treatment groups. Serum osmolality increased with salinity and was significantly higher (p < .05) for fish in K⁺‐amended saline groundwater (353–361 mOsmol/Kg) than in reconstituted seawater (319–332 mOsmol/Kg), although differences were not observed between salinities by water type. Cobia stocked in saline groundwater of different salinities were osmoregulating normally, and the higher values observed may be because of variations in ionic composition and other interfering ions in saline groundwater. Trial results suggest that juvenile cobia can achieve optimal growth in K⁺‐amended saline groundwater of low and intermediate salinities.     

Productivity of Sargassum linearifolium in potassium fortified inland saline water under laboratory conditions

Growing aquatic species in inland saline water (ISW) is one way to reduce the adverse impact of ISW to agriculture farms. This 84‐day laboratory‐trial was conducted to study the growth of Sargassum linearifolium cultured in ocean water (OW), ISW, ISW fortified with potassium equivalent to 100% (ISW100), 66% (ISW66) and 33% (ISW33) of potassium in OW at 35 g/L. The biomass and cumulative specific growth rate (SGR) of S. linearifolium increased significantly (p < .05) with increased potassium in ISW until 56 days and then declined. The ISW100 and OW resulted in similar growth patterns and yielded peak biomass at day 42, proving static biomass for the next 28 days before declining. The biomass of S. linearifolium cultured in ISW and ISW33 significantly (p < .05) decreased and was lower than in ISW100 and died after day 56. The SGR of S. linearifolium in OW, ISW100 and ISW66 levelled off and showed no difference during the first 56 days. The S. linearifolium biomass and SGR negatively and significantly (p < .05) correlated with the concentrations of nitrate, phosphate in all waters. The increased potassium concentration in ISW similar to its concentration in SW brought the growth of S. linearifolium cultured to a level that was similar in OW.