内蒙古典型草原蝗虫群落结构和生态位研究

采用定点调查和生物量定量分析方法对内蒙古典型草原不同草地蝗虫群落结构和生态位进行研究,结果表明,典型草原蝗虫群落结构丰富,主要蝗虫有11种,草原蝗虫的时间分布揭示了蝗虫时间生态位的分化,宽须蚁蝗[Myrmeleotettix palpalis(Zubowsky)],亚洲小车蝗(Oedaleus decorus asiaticus B.-Bienko)、短星翅蝗(Calliptamus abbreviatus Ikonnikov)分别构成镶黄旗草原蝗虫早期、中期、晚期优势种;根据蝗虫种群地位,将11种蝗虫划分为优势种、附属种、稀少种,把11种蝗虫按空间地位划分为禾草地类、荒草类、特殊类和全域类4类,优势种蝗虫的种群与空间地位,反映了蝗虫与植被、蝗虫与蝗虫之间关系。优势种蝗虫中短星翅蝗的时空生态位宽度最大,其次是亚洲小车蝗和宽须蚁蝗,说明短星翅蝗对时空"资源"的利用程度最高,共存的蝗虫种类在"资源"利用上存在着明显的分化,亚洲小车蝗与宽须蚁蝗的生态位重叠最大,说明两者利用资源的相似性程度最高。我们用生态位来体现蝗虫种群地位及对资源的利用,同时也用资源的系统聚类来预测蝗虫的潜在发生与危害。本文系统地研究了蝗虫群落结构和蝗虫生态位,将为评价草原蝗虫潜在发生与危害、蝗虫宜生区划分和制定草原有害生物防治策略提供理论基础。     

模拟增温、施氮对荒漠草原土壤中小型动物群落的影响

为了解全球气候变化对内蒙古荒漠草原土壤动物的影响,以四子王旗短花针茅荒漠草原为研究对象,采用野外增温、施氮、增温施氮和对照处理,观测土壤中小型动物群落的变化。结果表明,荒漠草原土壤动物不同类群对增温、施氮的响应不同:1)增温显著降低短花针茅荒漠草原鞘翅目幼虫类群数,对其它土壤动物无显著影响;施氮显著提高弹尾目昆虫的密度以及中气门亚目昆虫的密度和类群数,对其它土壤动物无显著影响;增温施氮显著降低鞘翅目幼虫密度和类群数,对其它土壤动物无显著影响。2)短花针茅荒漠草原土壤中小型动物有明显表聚性,其中增温施氮0-10cm密度显著高于10-20cm;施氮0-10cm密度和类群数均显著高于10-20cm。研究表明,气候变暖和氮沉降有可能影响土壤动物的群落组成和垂直结构。     

喀斯特石漠化地区土壤动物功能类群及培育研究

为了解石漠化地区土壤动物功能类群对生态恢复的响应,2010年9月至11月在贵州花江喀斯特峡谷区对不同石漠化等级的土壤动物进行了田间培育研究。结果显示:喀斯特石漠化区土壤动物可以划分为杂食性、植食性、腐食性和捕食性4个生态功能类群,各样地均以杂食性动物的物种数量和个体数量所占比例最大,捕食性动物所占比例较小;土壤动物功能类群随石漠化程度加深,物种数减少,个体数量不存在这种关系;物种丰富度、Shannon多样性指数随着石漠化程度加深而升高,均匀性、优势度指数则趋于下降;土壤动物培育发现,不同等级石漠化对土壤动物功能类群分布有影响,土壤动物种类和数量分布可以揭示石漠化生态恢复现状。     

宁夏草原蝗虫多样性及其对环境因子的响应

为明确宁夏四类主要草原的蝗虫物种组成、多样性和对天敌、植被、土壤及其气候等生物和非生物因子的响应,2019-2020年在宁夏温性草甸草原、温性草原、温性荒漠草原和温性草原化荒漠四类草原对蝗虫及天敌物种进行了调查采集,通过物种数、个体数、多样性指数、优势度指数、丰富度指数及均匀性指数分析蝗虫、天敌和昆虫的多样性,并就草原蝗虫优势种和多样性对天敌、植被、土壤及气候等生物和非生物因子的响应进行分析。结果表明,共采集鉴定草原蝗虫和天敌个体数分别有743头和3592头,物种数分别有27种和24种;温性草原上发生的蝗虫和天敌物种和数量均最多,蝗虫和天敌的物种分别为23种和21种,数量分别为432头和1682头;温性草原化荒漠上发生的蝗虫和天敌物种和数量均最少,蝗虫和天敌的物种分别为8种和7种,数量分别为34头和132头。蝗虫优势种有白纹雏蝗Chorthippus albonemus、短星翅蝗Calliptamus abbreviatus和亚洲小车蝗Oedaleus asiaticus三种,天敌优势种有直角通缘步甲Pterostichus gebleri、麻步甲Carabus brandti和短翅伪葬步甲Pseudotaphoxenus brevipennis三种。温性草原无论是在草原蝗虫群落中,还是整个昆虫和天敌群落中,其丰富度指数均显著高于其他三类草原;草原蝗虫多样性指数和丰富度指数与天敌多样性指数和丰富度指数间均存在极显著正相关关系,与天敌优势度指数间存在极显著负相关关系;短星翅蝗和亚洲小车蝗发生均与天敌直角通缘步甲呈显著正相关关系,白纹雏蝗与禾本科植被盖度、高度、生物量,菊科植被盖度、生物量、频度、高度、土壤饱和持水量、毛管持水量、田间持水量、毛管孔隙度、总孔隙度、有机质、碱解氮、海拔和降水量间均呈显著正相关关系,与土壤容重、pH、平均气温和最高气温间均呈极显著负相关关系。     

新疆吉木萨尔县林场大、中型土壤动物群落组成及季节动态研究

为探讨山地生态系统不同生境对大、中型土壤动物群落结构特征的影响,分别于2009年4月、7月及9月对天山北麓中段吉木萨尔县林场山地生态系统的5种不同生境,即云杉林、山前草甸、山地草原、山地农田及山间河滩中的大、中型土壤动物群落进行了采样研究。共捕获大、中型土壤动物个体14727只,分别隶属于6门16纲39目(40类)。其中弹尾目和真螨目为优势类群,二者分别占总数的38.61%,25.54%。鞘翅目、寄螨目、膜翅目、蜘蛛目、鞘翅目幼虫、双翅目幼虫、颤蚓目、鳞翅目幼虫等8类为常见类群,共占总数的26.38%,优势类群和常见类群共占总数是的90.53%,这二类组成了该区大、中型土壤动物的基本成分。其余的30类为稀有类群,占总数的9.47%。研究还发现,山地不同生境大、中型土壤动物类群和个体数之间、不同季节之间、不同土层之间以及群落多样性之间均存在显著差异(P>0.05)。通过该区不同生境大、中型土壤动物群落的聚类和排序结果,将5种不同山地生境分为云杉林-山地草原生境类型和山前草甸-山地耕地-山间河滩生境类型两大类型。     

内蒙古草原退化群落恢复演替的研究 Ⅳ.恢复演替过程中植物种群动态的分析

本文根据 1 983-1 993年退化草原群落恢复演替过程中主要植物种群地上现存量与密度的变化 ,将这些种群区分成 6种类型 :优势增长型—羊草 (Leymuschinensis) ;缓慢增长型—大针茅 (Stipa grandis) ;典型衰退型—糙隐子草 (Cleis-togenes squarrosa)和变蒿 (Artemisia commutata) ;迟滞衰退型—冷蒿 (Artemisiafrigida) ;中间过渡型—米氏冰草 (Agropyron michnoi)、双齿葱 (Allium bidenta-tum)和洽草 (Koeleria cristata) ;演替中立型—小叶锦鸡儿 (Caragana microphyl-la)。并依据各种群的拓殖 ,生物产量和根系分布等生物学特性分析了各种群在恢复演替中的作用。根据种群根系分布范围与种群密度变化的关联 ,本文提出“恢复演替的作用域扩展”概念。在过度放牧导致草原退化演替中 ,表现出群落地上部分矮化和地下部分的浅层化 ,恢复演替则表现其逆过程。当恢复演替开始后 ,浅层土壤中最先出现拥挤 ,浅根性植物种群趋于衰退 ,也促使一些种群向土壤深层发展。表现出种群更替的作用空间扩展的趋势。其中衰退种群植株死亡后的资源空间可使拓殖能力强的种群或原种群增长。于是资源与种群增长构成一个反馈调节环。反馈调节使群落演替自组织过程表现出方向性。在恢复演替过程中各种群的数量指标均表现出波动性     

1982-2014年内蒙古自治区温带草原生态系统服务价值及其空间分布

生态系统服务价值评估有利于将生态资源量化为生态资产,使生态效益最大化.本研究基于单位面积生态系统服务价值当量因子估算法,利用1982-2014年遥感数据估算的生物量和空间插值的年降水量数据两个生物环境因素对4大类、11小类的单位面积生态系统服务价值当量因子进行了校正,进而估算了内蒙古自治区温带草原生态系统服务价值及其空间分布特征.结果表明:1982-2014年33年间:1)内蒙古自治区温带草原单位面积总生态系统服务价值平均为29780.3 元/hm2.其中,荒漠草原、典型草原和草甸草原单位面积总生态系统服务价值平均分别为2097.71元/hm2、27110.7元/hm2和126620元/hm2.2)内蒙古自治区全区温带草原生态系统服务价值为1.6万亿元/年,其中调节服务价值(1.07万亿元/年)＞支持服务价值(0.31万亿元/年)＞供给服务价值(0.11万亿元/年)＞文化服务价值(0.11万亿元/年).3)内蒙古自治区全区温带草原生态系统服务价值总体上呈现从东北向西南逐渐降低的空间分布特征,草甸草原生态系统服务价值(0.82万亿元/年)＞典型草原(0.77万亿元/年)＞荒漠草原(0.02万亿元/年).草原生态服务价值巨大,对生态文明建设起着积极作用,为制定合理的区域生态文明建设路径提供了较为可靠的数据支撑.     

新疆喀纳斯国家自然保护区中小型土壤动物群落特征研究

2011年7-9月对喀纳斯自然保护区针叶林、针阔混交林、阔叶林、灌木林、草甸草原、林间草地、沼泽地7种生境下中小型土壤动物类型特征、动态变化进行了实地调查。结果表明:捕获中小型土壤动物共14301只,隶属于4门13纲29目(30类),其中甲螨目、弹尾目和垫刃目为优势类群。中气门目、无气门目、蛭态目、前气门目、茅线目和双翅目幼虫为常见类群,占总数量的21.14%,其余的23类均为稀有类群,只占总捕获量的4.46%。在不同生境中小型土壤动物群落类群数之间差异显著(p0.05),而个体数之间差异极显著(p0.01),其中个体数水平分布表现为针阔混交林阔叶林针叶林灌木林林间草地草甸草原沼泽地,类群数顺序为阔叶林灌木林针阔混交林林间草地针叶林草甸草原沼泽地。在垂直分布上具有明显的表聚性特征,即0～5cm5～10cm10～15cm,但针叶林、阔叶林和混交林苔藓层个体数与类群数极显著高于凋落物层和土壤层(p0.01)。个体数的季节动态变化顺序为秋季多,而夏季少,但类群数在夏季多,而秋季少。     

火烧对典型草原改良的效果

本文研究了秋季火烧和春季火烧对内蒙古草原地带的羊草草原总产量优势种群羊草、大针茅以及小叶锦鸡儿数量与生长状况的影响。自１９９０年秋至１９９２秋经过两年的监测、统计与分析，主要研究结果如下：草场的总产量受大气降水的制约，火烧前后草场的总产量基本上保持稳定，中常年景的地上生物量变化在１８０──２００克／平方米之间。火烧对优质根茎禾草一羊草的增长有显著的促进作用，在生长季的中后期，火烧地段上羊草种群的地上生物量比未烧地段高出５０──９０克／平方米，提高了６００──１６０％。火烧地段上豆科草的产量略有提高，而葱类植物的产量基本上保持稳定。火烧可以抑制大针茅、小叶锦鸡儿和菊科杂类草的生长，减少它们的数量，其中以秋季火烧最为明显。在对照群落中，大针茅的产量为３０──５０克／平方米，小叶锦鸡儿为２０──５０克／平方米，火烧之后大针茅的产量减至１０──２５克／平方米，减少了５０──６０％，小叶锦鸡儿的产量一般低于１０克／平方米。火烧对草场的效应与各种植物的生活型、生长型、种群生态位（对水分和养分等资源利用情况）等特点紧密相关。火烧对草原土壤理化性质的影响也是有关因素。综上所述，有计划的火烧可以提高草群质量和利用价值，是一种?     

不同改良措施对典型草原植物群落及土壤的影响

于2010年4-9月在宁夏云雾山草原自然保护区实验区内对草地进行各种改良措施应用试验,以寻求加快宁南半干旱区草原生态恢复的关键技术.改良后的测定结果表明:草地松耙后的植物群落多样性与对照之间差异不显著(P＜0.05),盖度和生物量明显低于对照,分别低7％、32.4 g·m-2;草地松耙、草地松耙+补播、草地松耙+施肥、草地松耙+补播+施肥、围栏封育处理后的土壤含水量与对照之间差异显著(P＜0.05),容重均小于对照；草地松耙+补播+施肥的土壤养分与对照之间差异显著(P＜0.05).     

Impact of Fire on Soil Nitrogen Forms in Central Semiarid Argentina

Burning effects on soil N are particularly important in the Caldenal region of Argentina because N is likely to be limited and is easily lost by volatilization during fire. Burning may cause an initial increase in the mineral N content of the surface soil and, perhaps more important, can reduce the proportion of N in hydrolyzable (that is, more mineralizable) forms. The modification in soil N fractions by fire is directly related to the degree of soil heating and to the proportion and amount of N fractions remaining in the ash. This research was aimed at studying the effects of a controlled burn on total N, inorganic (NO3 and NH4+) and organic (amino acids, ammonium, hexosamines) N forms, as well as hydrolyzable and nonhydrolyzable N compounds of top soils of the southern Caldenal. Soil samples were taken from beneath the canopy of shrubs and from the areas with herbaceous cover, before and after burning. In order to show that a greater proportion of N added to regularly burned soils will result in lower levels of mineralizable N, differences in the changes of the various pools of plant tissue N upon burning at different ignition tem peratures are also reported. The initial unburned top soils had no significant differences in total, inorganic, and organic N form concentrations between shrub and herbaceous vegetation-covered soil. Burning did not affect the net content of total N in soil under woody vegetation, but in the grassland soil a decrease of total N concentration was observed. Nitrate concentration increased and NH4+ concentration decreased in both shrub and grassland soils after burning. Controlled burning caused losses of amino acid and ammonium organic N forms from the soil under grass plants and gains of hexosamine N in both shrub-and herbaceous-coveredsoils. There was an observed tendency to increase the relative proportions of non hydrolyzable N forms in both the shrub and grassland soils after burning. Inorganic and organic N form concentrations were similar in initial shrub litter and grass, but litter had higher concentrations of total and nonhydrolyzable N than those of grass. Shrub litter ash obtained after muffling at 300 C contained higher NH4+-N, aminoacid N, ammonium N, and total and nonhydrolyzable N concentrations than those from grass. An increase of 100 C in the ignition temperature produced clear ashes, rich in mineral N with little concentration of total N and C. The organic N forms affected most by the ignition temperature increase were amino acid N and ammonium N, respectively, particularly in woody litter. The most striking feature was the constituent increase in the percentages of nonhydrolyzable N forms of the vegetation covers on passing from initial to 300 C to 400 C, particularly for the litter and its ashes. These results suggest that the soil mineralizable N pool may be reduced by frequent burning or by more severe burning than observed presently in the Caldenal region.     

草地可燃物床特性与草地火行为的关系

采用室内实验与野外实验相结合的方法研究草地可燃物床特性与草地火行为的关系。结果表明：可燃物量、可燃物床体积密度、可燃物床孔隙度、可燃物空间配置、坡度对火行为都有一定的影响。     

火生态因子对草原的效应及有计划用火的研究

火烧可以提高禾草类的生物量25—30%,可以快速地(当年)大幅度提高羊草种群的生物量达100%以上。火烧提高羊草的抽穗率,促进草群更新复壮。火烧可以有效地抑制针茅种群的增长,并改变群落中的种群分布格局,促进羊草种群形成均匀分布格局,扩大羊草种群在群落中的生态位。火烧对草原的总生产力不发生负效应,一次火烧的正效应可持续2—3年。基于以上的结果,我们认为锡林郭勒草原区中,东部含有羊草的草原群落,可在春季四月下旬进行火烧,将会取得良好的效果。     

Effects of spring fire and slope on the aboveground biomass,and organic C and N dynamics in a semi-arid grassland of northern China

The aboveground primary production is a major source of carbon(C) and nitrogen(N) pool and plays an important role in regulating the response of ecosystem and nutrient cycling to natural and anthropogenic disturbances. To explore the mechanisms underlying the effect of spring fire and topography on the aboveground biomass(AGB) and the soil C and N pool, we conducted a field experiment between April 2014 and August 2016 in a semi-arid grassland of northern China to examine the effects of slope and spring fire, and their potential interactions on the AGB and organic C and total N contents in different plant functional groups(C_3 grasses, C_4 grasses, forbs, Artemisia frigida plants, total grasses and total plants).The dynamics of AGB and the contents of organic C and N in the plants were examined in the burned and unburned plots on different slope positions(upper and lower). There were differences in the total AGB of all plants between the two slope positions. The AGB of grasses was higher on the lower slope than on the upper slope in July. On the lower slope, spring fire marginally or significantly increased the AGB of C_3 grasses, forbs, total grasses and total plants in June and August, but decreased the AGB of C_4 grasses and A.frigida plants from June to August. On the upper slope, however, spring fire significantly increased the AGB of forbs in June, the AGB of C_3 grasses and total grasses in July, and the AGB of forbs and C_4 grasses in August. Spring fire exhibited no significant effect on the total AGB of all plants on the lower and upper slopes in 2014 and 2015. In 2016, the total AGB in the burned plots showed a decreasing trend after fire burning compared with the unburned plots. The different plant functional groups had different responses to slope positions in terms of organic C and N contents in the plants. The lower and upper slopes differed with respect to the organic C and N contents of C_3 grasses, C_4 grasses, total grasses, forbs, A. frigida plants and total plants in different growing months. Slope position and spring fire significantly interacted to affect the AGB and organic C and N contents of C_4 grasses and A. frigida plants. We observed the AGB and organic C and N contents in the plants in a temporal synchronized pattern. Spring fire affected the functional AGB on different slope positions, likely by altering the organic C and N contents and, therefore,it is an important process for C and N cycling in the semi-arid natural grasslands. The findings of this study would facilitate the simulation of ecosystem C and N cycling in the semi-arid grasslands in northern China.     

Effects of recovery time after fire and fire severity on stand structure and soil of larch forest in the Kanas National Nature Reserve,Northwest China

Forest recovery may be influenced by several factors, of which fire is the most critical. However, moderate- and long-term effects of fire on forest recovery are less researched in Northwest China. Thus, the effects of different forest recovery time after fire (1917 (served as the control), 1974, 1983 and 1995) and fire severities (low, moderate and high) on larch (Larix sibirica Ledeb.) forest were investigated in the Kanas National Nature Reserve (KNNR), Northwest China in 2017. This paper analyzed post-fire changes in stand density, total basal area (TBA), litter mass, soil organic carbon (SOC) and soil nutrients (total nitrogen, total phosphorus and total potassium) with one-way analyses of variance. Results indicate that litter mass, TBA, SOC and soil nutrients increased with increasing recovery time after fire and decreasing fire severity, while the stand density showed an opposite response. The effects of fire disturbance on SOC and soil nutrients decreased with increasing soil depth. Moreover, we found that the time of more than 43 a is needed to recover the litter mass, TBA, SOC and soil nutrients to the pre-fire level. In conclusion, high-severity fire caused the greatest variations in stand structure and soil of larch forest, and low-severity fire was more advantageous for post-fire forest stand structure and soil recovery in the KNNR. Therefore, low-severity fire can be an efficient management mean through reducing the accumulation of forest floor fuel of post-fire forests in the KNNR, Northwest China.     

浑善达克地区生态环境劣化原因分析及治理对策

本文阐述了浑善达克沙化草原区的自然环境特征、社会经济情况和生态环境退化现状。从系统物流平衡、环境气候变化 ,以及人类活动对草地生态系统的影响等方面探讨了该地区生态环境劣变的原因。分析结果表明 ,放牧畜牧业是该地区的牧业主要生产方式 ,家畜是生态系统中植被的主要控制者 ,系统内物流 (以 N为例 )的出入失调和季节性的草 -畜供求失衡是引起草地生态系统迅速退化的主要因素。而其它因素 (如气候变化、垦荒、挖药材等 )对系统的劣变起了推波助澜的作用。著者指出 ,增加向系统内的物质投入 ,调整四季放牧的自然畜牧业生产方式 ,积极引种入牧 ,缓解草地春季敏感期放牧压力等 ,是治理和维护该地区草地生态系统健康的有效措施     

Monitoring fire regimes and assessing their driving factors in Central Asia

Relatively little is known about fire regimes in grassland and cropland in Central Asia. In this study, eleven variables of fire regimes were measured from 2001 to 2019 by utilizing the burned area and active fire product, which was obtained and processed from the GEE(Google Earth Engine) platform, to describe the incidence, inter-annual variability, peak month and size of fire in four land cover types(forest, grassland, cropland and bare land). Then all variables were clustered to define clusters of fire regimes with unique fire attributes using the K-means algorithm. Results showed that Kazakhstan(KAZ) was the most affected by fire in Central Asia. Fire regimes in cropland in KAZ had the frequent, large and intense characters, which covered large burned areas and had a long duration. Fires in grassland mainly occurred in central KAZ and had the small scale and high-intensity characters with different quarterly frequencies. Fires in forest were mainly distributed in northern KAZ and eastern KAZ. Although fires in grassland underwent a shift from more to less frequent from 2001 to 2019 in Central Asia, vigilance is needed because most fires in grassland occur suddenly and cause harm to humans and livestock.     

浑善达克沙地重度沙化区与干旱梯度空间相关性初探

根据浑善达克沙地及其毗邻地区16个气象台站自1965以来的气象数据,结合地面考察与实地测定,对浑善达克沙地的重度沙化区与干旱梯度的空间相关性及原因进行了研究。结果表明:气候分区-2中出现了东部的重度受损区域主要是由于这一区域的降水量与草甸草原区的降水持平,但热量条件更为优越,适合农垦,所以成为农牧交错带。但沙地基质的流动性决定了在这一区域进行农业生产的不可持续性,大面积沙地被开垦为农田后又被弃耕,出现大面积的次生裸沙地。气候分区-4中出现了浑善达克沙地中面积最大的重度受损区,这一区域气候特点属于典型草原到荒漠草原的过渡类型,沙地的原生植被以多年生草本和旱生灌木为主。由于强度放牧以及相对匮乏的降雨造就了本区内的大面积沙化。     

Soil seedbanks in slash‐and‐burn rice fields of northern Laos

Crops in shifting cultivation fields often suffer from severe weed infestation when long fallow periods are replaced by short fallow periods. The soil seedbank as a source of weed infestation was studied in four fields that differed in their last fallow duration. The effect of burning was analysed by comparing adjacent pre‐burn and post‐burn samples (two sites). Surface vegetation was monitored from burning to harvest in the plots from which soil samples were taken to determine the fraction of the seedbank germinating (three sites). Seedbank size (1700–4000 seedlings m^?2) varied depending on a single species, Mimosa diplotricha. Burning reduced emergence of most species, but stimulated emergence in others. Densities in the seedbank were not correlated with above‐ground abundances in the field, except for some species. Most species emerging after 50 days from the soil samples (40% of seedlings) were absent from the field after 190 days. Whilst the data from this study are derived from only four fields, the weed problems after short‐term fallowing appeared to be due to a larger fraction of the seedbank emerging, possibly due to shallow burial, and to a floristic shift towards adaption to burning, rather than the size of the seedbank per se.