藿香蓟能否选为柑橘园生草优势草种

多年来,在学校柑橘园管理实践中,师生们一直在探索自然生草栽培模式,积累了不少经验,但是一直没有优选出相对固定的野生草种,使得柑橘园野草乱生,影响柑橘生长。为此,我们进行柑橘园优势野生草种选育探究。

泰沂山区苹果园自然生草优势草种类及养分特征

为研究自然生草在改善苹果园管理水平方面的作用,2014—2015年,在山东省果树研究所肥城市安驾庄镇边院村矮砧苹果试验园进行自然生草试验。结果表明:春、夏二季(4月至7月中旬)是各种草的主要发生期;不同时期的优势草种存在一定差异;泰沂山区苹果园优势草种有荠、藜、绿穗苋、狗尾草、马唐、牛筋草、马齿苋等。6月中旬以前,草的种类相对较少,产草量较低;进入6月下旬,草的种类增多,产草量较高,全年每666.7m2干草产量约420.4 kg。自然生草的氮素含量为2.17%~4.17%,除绿穗苋外,其余草种的氮素含量与人工生草的相差不大;磷素含量分别为0.65%~1.45%,与人工生草相比,其平均含量相对较高;钾素含量为3.57%~9.33%,除春季草荠菜外,均明显高于所检测人工生草的钾含量。综上结果表明,自然生草能有效改善苹果园的管理水平。

河道边坡护坡最佳草种组合筛选的研究

河道护坡水土流失严重,加剧了河道护坡生态环境恶化。通过对长治地区河道护坡人工植被组合筛选的研究,确定了河道护坡的优势草种组合。

常熟市麦田杂草调查与发生特点初析

通过样方计数法和7级目测法对麦田杂草进行调查,摸清当前常熟地区麦田主要优势草种为日本看麦娘+菵草+猪殃殃,分析当前麦田杂草的发生特点,提出相应的综防措施。

洛川旱地苹果园自然草被群落特征研究

【目的】探究旱地苹果园草被群落演替特征和生态适应性,为人工干预自然生草过程中草被高效管理提供参考。【方法】以洛川县凤栖镇苹果园为代表,调查了果园全年草本植物的发生特点及群落组成,用不同时期的草种密度计算Margalef丰富度指数、辛普森指数、生态位指数和统计草本植物全年相对高度、根长等指标,筛选适合旱地苹果园自然生草的优良草本植物种类。【结果】以洛川县凤栖镇为代表的旱地苹果园中,草本植物共32种,隶属于15个科。春季以繁缕、藜科、十字花科草本植物为主,入夏后十字花科草本植物逐渐消退,繁缕、禾本科和菊科草本植物占主导位置,直至11月,8、9月为苹果园全年草本植物丰富度指数最高的月份。狗尾草、虎尾草、稗草、马唐、繁缕这5种草在果园中年覆盖时间最长,覆盖密度最大。【结论】果园的自然生草群落会随着季节变化而变化,综合所有结果筛选出,狗尾草、虎尾草、马唐、稗草、繁缕、蒲公英、苣荬菜、活血丹可作为旱地苹果园自然生草的优良草本植物种类。

黑麦草、高羊茅、早熟禾成坪期生长势与分蘖力测定分析

探明特定生态环境草坪草种地上营养器官茎、枝(蘖)、叶的生长发育特点,不同品种组合表现特性是一个地区开展草坪建植的重要依据,此测定分析显示四川西南部亚热带暖温区秋播冷季型草生长势强的优势种是高羊茅、黑麦草,生长发育较慢的优势种为早熟禾;组合比例初步看出高羊茅、黑麦草约占80%,早熟禾约占20%为好;组合播种量初步指出以15～30g/m2为宜。

Analysis of the Species Dominance & Dominant on the Karst Mountain Grassland Plant Community

[Objective] The aim was to study the species,quantity and community traits of dominant plant in karst mountain grassland plant community so as to provide support for the vegetation restoration in karst mountain grassland.[Method] Standard plot sites investigation method was used study the quantity traits of different plant communities of different altitudes and slopes.[Result] The IV SDR4 were the highest in the all plot sites of plant community on the kasrt mountain grassland,but the IV SDR4 were showed a trend of decreasing with the increasing of the altitude.The dominant quantity was increasing with the altitude upward,so the altitude was the mostly factor for plant community construction.[Conclusion] Altitude was the main factor to influence the community structure of plant.

Herbivores alleviate the negative effects of extreme drought on plant community by enhancing dominant species

Aims Both extreme drought and insect herbivores can suppress plant growth in grassland communities.However,most studies have examined extreme drought and insects in isolation,and there is reason to believe that insects might alter the ability of grasslands to withstand drought.Unfortunately,few studies have tested the interactive effects of extreme drought and insect herbivores in grassland communities.Methods Here,we tested the drought–herbivore interactions using a manipulative experiment that factorially crossed extreme drought with the exclusion of insect herbivores in a temperate semiarid grassland in Inner Mongolia.Important Findings Our results demonstrated that both extreme drought and insect herbivores separately decreased total plant cover.When combined,insect herbivores reduced the impact of drought on total cover by increasing the relative abundance of drought-resistant dominant species.Our results highlight that the negative effect of extreme drought on total plant cover could be alleviated by maintaining robust insect herbivore communities.

Changes in vegetation and soil properties following 6 years of enclosure in riparian corridors

Aims Riparian corridors play vital roles in the maintenance of biodiversity.Nonetheless,plant species diversity and vegetation coverage in riparian corridors are seriously threatened by increasing pressure owing to livestock consumption and anthropogenic disturbance;even the stability of river courses has been threatened.The establishment of enclosures is a widely used strategy to restore degraded grassland ecosystems,but its impact on degraded herbaceous riparian vegetation and soil properties remains unclear.The aim of this study was to evaluate whether species composition,richness,diversity,and soil properties can be recovered by the enclosure.Methods Twenty long-term monitoring sample plots were set in the Liaohe main stream river,Liaohe main stream river was enclosed for grazing and farmland exclusion in 2012.The height,coverage and individual numbers of plant were recorded for species richness and diversity evaluation from 2012 to 2017;soil nutrients were measured for comparative analysis in 2012 and 2017.We examined the effects of the establishment of enclosures on plant species diversity and soil properties from 2012 to 2017 in the riparian corridors of the Liaohe River system in China.Important Findings Plant species richness and diversity significantly increased from 2012 to 2017.The dominance of Asteraceae plants increased,while the abundance of Gramineae plants decreased over time.The difference in abundance increased each year since enclosure was implemented in 2012.The concentrations of phosphorus and potassium in the soil significantly decreased as a result of the combined effects of vegetation restoration and prohibition of farming practices following the establishment of enclosures.There was also a lag time related to the response of soil organic matter to the establishment of enclosures.In conclusion,our study provides new evidence regarding the response of species diversity,species composition and soil properties following riparian vegetation restoration efforts through enclosure development.

Above-and belowground trait linkages of dominant species shape responses of alpine steppe composition to precipitation changes in the Tibetan Plateau

Aims Human activities and global changes have led to alterations in global and regional precipitation regimes.Despite extensive studies on the effects of changes in precipitation regimes on plant community composition across different types of grassland worldwide,few studies have specifically focused on the effects of precipitation changes on high-altitude alpine steppe at community and plant species levels in the Tibetan Plateau.Methods We investigated the effects of growing-season precipitation changes(reduced precipitation by 50%,ambient precipitation,enhanced precipitation by 50%)for 6 years on plant community composition in an alpine steppe of the Tibetan Plateau by linking above-to belowground traits of dominant species.Important Findings We found that reduced precipitation shifted community composition from dominance by bunchgrass(primarily Stipa purpurea)to dominance by rhizomatous grass(primarily Leymus secalinus).Roots and leaf traits of L.secalinus and S.purpurea differed in their responses to reduced precipitation.Reduced precipitation enhanced root vertical length and carbon(C)allocation to deep soil layers,and decreased the leaf width in L.secalinus,but it did not change the traits in S.purpurea.Moreover,reduced precipitation significantly enhanced rhizome biomass,length,diameter and adventitious root at the rhizome nodes in L.secalinus.These changes in traits may render rhizomatous grass greater competitive during drought stress.Therefore,our findings highlight important roles of above-and belowground traits of dominant species in plant community composition of alpine steppe under precipitation change.