Species-diversified plant cover enhances orchard ecosystem resistance to climatic stress and soil erosion in subtropical hillsid

Naturally occurring plants in agroecosystem evidently play an important role in ecosystem stability. Field studies on the ecological effects of native plants conserved in orchard and their resistance to adverse climatic stress, and soil erosion were conducted from 1998 to 2001 in a newly developed Changshan-huyou (Citrus changshan-huyou Y.B. Chang) orchard. The experimental area covered 150 ha in typical red soil hilly region in southeastern China. The experimental design was a randomized complete block with six combinations of twelve plant species with four replications. All species used were native in the orchard. Plots were 15×8m^2 and separated by 2m buffer strips. Precipitation, soil erosion in rainstorm days and aboveground biomass of plant community when rainstorm days ended, soil temperature and moisture under various plant covers during seasonal megathermal drought period, antiscourability of soil with different root density under various simulated rainfalls were measured. Plant cover significantly decreased the daily highest and mean soil temperature and its daily variation in hot-drought season, but there was no significant difference of the alleviation among various plant covers. Plant covers significantly increased the soil moisture in seasonal megathermal drought period. Better moisture maintenance and soil erosion reduction was found when the plant species numbers in cover plant communities increased from one to eight. Higher root density in plant communities with higher species richness increased significantly the antiscourability of the soil. It was suggested that conserving plant communities with diversified native species could produce the best positive ecological effects on citrus orchard ecosystem stability.

Analysis of Application Status and Recommendations for Shade-Tolerant Lawns and Ground Cover Plants in the West Lake Scenic Area

Taking 8 parks in Xihu Scenic Area as the survey objects, this study found that there are 77 kinds of shade-tolerant lawns and ground cover plants under the forest in good growth condition, and there are 3 types of application forms: dense forest, sparse forest and forest edge. In response to the existing problems, it is proposed that it is necessary to adhere to principles of ecology, adapt to local conditions and plant suitable varieties in accordance with local conditions, develop and use new varieties of wild shade-tolerant lawns and ground cover plants, and strengthen the promotion of the mixed planting model of shade-tolerant lawns and ground cover plants, so as to provide guidance for the better use of shade-tolerant lawns and ground cover under the forest in the West Lake Scenic Area in the future.

Study on the Ground Cover Plant in Tibetan Herb Garden

This paper conducts a comprehensive survey of the ground cover plant in Tibetan herb garden for the first time using " five-point sampling method". Survey results show that:(i) A total of 46 families,95 genera,119 species of ground cover plants in herb garden are applied in Tibet,and Asteraceae,Gramineae,Leguminosae,Labiatae,Iridaceae and Liliaceae are used most,with the species number of 22,15,8,7,6 and 5,respectively,accounting for 18. 49%,12. 61%,6. 72%,5. 88%,5. 04% and 4. 20% of the plants surveyed,respectively.(ii) In terms of importance value for the herbaceous layer,the top three plants are Poa pratensis L.,Festuca arundinace and Lolium multiflorum L.,with the importance value of 45. 950,34. 610 and 29. 880,respectively; in terms of importance value for the non-turf ground cover herb plants,the top three plants are Trifolium L.,Cosmos bipinnata Cav. and Althaea rosea(Linn.) Cavan.,with the importance value of4. 372,3. 437 and 2. 062,respectively.(iii) The overall level of greening is low and uneven in the region,with large regional differences. In terms of ground cover plant abundance,Nyingchi > Lhasa > Shannan > Changdu > Xigaze > Ali > Nagqu.

Allelopathic Effect of Black Pine( Pinus thunbergii) Needles and Litter on Four Cover Plants

Black pine( Pinus thunbergii) is one of the main afforestation species in the sandy coast and the preferred tree species for landscape green in northern China.Allelopathic activity could be one of the reasons of the sparse vegetation under black pine forests.To explore the allelopathic potential of P.thunbergii,the effects of litter and fresh needles were evaluated against the common cover plants seeds and seedlings,i.e.Tateges erecta,Orychophragmus violaceus,Ophiopogon japonicas and Trifolium repens.The results showed that P.thunbergii possessed allelopathic potential to the accompanying plants.Increasing concentrations of aqueous extracts of needles and litter affected target plant development in different levels.Growth and germination inhibition were directly related to the extract concentrations of needles or litters.Fresh needles played a more important role in the inhibition to target plants than litter because of the less germination rate and biomass in the same concentration.In addition,the adaptability of cover plants to the allelopathic effects of P.thunbergii is obviously different.The sensitivities of the four cover plants to the allelopathic effects of P.thunbergii were in order of T.repens > O.japonicas > O.violaceus > T.erecta.Therefore,T.repens is least suitable for concomitant planting with P.thunbergii,and T.erecta is the most suitable,with other two plants in between in landscape configuration.

The Effect of Plastic-Covered Ridge and Furrow Planting on the Grain Filling and Hormonal Changes of Winter Wheat

Although plastic-covered ridge and furrow planting（RF） has been reported to produce substantial increases in the grain weight of winter wheat,the underlying mechanism is not yet understood.The present study used two cultivars,Xinong 538 and Zhoumai 18,and RF and traditional flatten planting（TF,control） with the objective of investigating the effect of RF on wheat grain filling and the possible relationship of hormonal changes in the wheat grains under RF to grain filling.The results indicated that RF significantly increased the grain weight,although the effects on grain filling were different： RF significantly increased the grain-filling rate and grain weight of inferior grains,whereas RF had no significant effect on grainfilling rate and grain weight of superior grains.The final grain weight of inferior grains under RF was 39.1 and 50.7 mg for Xinong 538 and Zhoumai 18,respectively,3.6 and 3.4 mg higher than the values under TF.However,the final grain weight of superior grains under RF was only 0.6 and 0.8 mg higher than under TF for Xinong 538 and Zhoumai 18,respectively.RF significantly decreased the ethylene and gibberellic acid content in the inferior grains and increased the indole-3-acetic acid,abscisic acid and zeatin ＋ zeatin riboside content in the inferior grains;however,no significant difference between RF and TF was observed for the hormonal content in the superior grains.Based on these results,we concluded that RF significantly modulated hormonal changes in the inferior grains and,thus,affected the grain filling and grain weight of the inferior grains;in contrast,RF had no significant effect on grain filling,grain weight and hormonal changes in the superior wheat grains.

Study on Ability of Ground Cover Plant of Taiyuan to Adsorb PM(2.5)

Four ground cover plant species of Taiyuan（ Iris,Hemerocallis,Sedum,Hosta） were selected to study their capacities in adsorbing PM（2.5）. Meanwhile,the concentration of PM（2.5） in Taiyuan between April 2017 and August 2017 was recorded,and the characteristics of PM（2.5） pollution in summer and autumn in Taiyuan were studied. The results showed that for the 4 plants,the ability to adsorb PM（2.5） was in the order from great to small of Hosta,Iris,Hemerocallis,Sedum,in which H. plantaginea had the best effect to adsorb PM（2.5）. The fresh weight and dry weight per gram of H. plantaginea were 4. 4 times and 2 times higher than those of S. spectabile,while the mass quality of dust adsorption was 2.8 times higher. The sorting result was the same as the ability to adsorb PM（2.5） of unit leaf area. The result of the coefficient of purification showed that the purification coefficients of 3 vegetation structure were positive,and the combination of trees and shrubs in university campus had strong PM（2.5） adsorption capacity. By comparing the seasonal variation of PM（2.5） concentration in Taiyuan city,it found that the PM（2.5） concentration was particularly high in late spring and early summer of Taiyuan,when most of the ground cover plants were not fully grown. Therefore,ground cover plants played an important role in the construction of landscape and the regulation of ecological environment in Taiyuan.

不同植物覆盖下蕉园土壤化学性质和酶活性的变化特征

【目的】通过对植物覆盖下蕉园土壤化学性质及酶活性进行研究,明确植物覆盖对蕉园土壤质量影响的变化特征,以期为用地养地结合的蕉园种植模式提供数据支持。【方法】以无覆盖物的传统裸露种植方式为对照,以人工种植大翼豆[Macroptilium atropurpureum(DC.)Urb]和自然生杂草为覆盖处理,通过连续3年田间小区定位试验,分析植物覆盖下蕉园土壤化学性质及酶活性的变化特征。【结果】植物覆盖显著改善了蕉园土壤化学性质及酶活性(P<0.05),与对照相比,大翼豆覆盖处理的土壤有机质、全氮、全磷、碱解氮、有效磷分别提升51.92%、38.00%、41.86%、20.85%、29.70%;大翼豆覆盖处理的土壤蔗糖酶、脲酶、过氧化氢酶及磷酸酶活性分别提高34.19%、50.28%、33.41%、101.54%。植物覆盖措施在1年内有效改善了蕉园土壤有机质、碱解氮及有效磷含量,而对土壤全氮及全磷含量的影响则需要覆盖处理2年以上才能达到显著水平;主成分分析结果表明,大翼豆覆盖处理对土壤酶活性影响较自然生杂草处理显著。【结论】与传统裸露种植方式相比,两种覆盖模式均显著提高了土壤化学性质和酶活性,且豆科植物覆盖效果明显优于自然生杂草,宽窄行种植配合豆科植物覆盖处理,能有效改善土壤质量,可作为云南干热河谷区域香蕉产业健康发展的技术模式。

旱区地膜与种植密度对棉花冠层光分布及产量的影响

棉花冠层光合有效辐射截获率(PARI)是影响干物质积累和产量形成的重要因素,然而对于不同覆膜方式下种植密度对棉花冠层光分布的影响尚未明确。在旱区一膜三行的机采种植模式下,设2种覆膜方式(有膜和无膜)与5种种植密度(D1:9×10^(4)株/hm^(2),D2:13.5×10^(4)株/hm^(2),D3:18×10^(4)株/hm^(2),D4:22.5×10^(4)株/hm^(2),D5:27×10^(4)株/hm^(2)),研究不同覆膜方式下种植密度对棉花冠层PARI的影响。结果表明,在全生育期,有膜处理下棉花冠层光合有效辐射(PAR)的截获能力较强;冠层PARI与种植密度呈显著正相关关系,不同种植密度之间PARI存在差异;叶面积指数(LAI)随生育进程推进呈单峰曲线。有膜处理下,不同种植密度LAI在第94~98天达到峰值;无膜处理下,不同种植密度LAI在第109~113天达到峰值;随着种植密度的增加干物质积累量减少,其生殖器官生物量有所下降。种植密度为18×10^(4)株/hm^(2)下的产量显著高于其他处理(有膜为5805.07 kg/hm^(2),无膜为5436.96 kg/hm^(2)),研究结果为旱区合理密植、构建合理的冠层结构提供理论依据。

呼和浩特市绿地建设中花境设计与应用研究

花境已成为草原都市-呼和浩特市绿地建设中一种较为常见的园林造景方式,可以极大地提高草原都市的生态景观品质和宜居水平。本文以2020—2023年呼和浩特市建设的花境为研究对象,通过对300余处花境的主题、应用环境、造型和构成材料等方面进行了调查分析,结果为花境设计中涉及生态主题的作品最多;花境中使用的花草种类126种,共涉及41个科104个属的草本植物,有75种花卉在呼市地区都有较好的性状表现和较高的推广价值。染色树皮、砾石、陶粒、火山岩、园林小品、景石和园林废弃物等资源作为花镜建设的构成材料。同时总结出一些在花境建设与养护过程中的共性问题,并给出合理的建议。

Transformation of vegetative cover on the Ustyurt Plateau of Central Asia as a consequence of the Aral Sea shrinkage

The gradual shrinkage of the Aral Sea has led to not only the degradation of the unique environments of the Aral Sea,but also numerous and fast developing succession processes in the neighborhood habitats surrounding the sea.In this study,we investigated the vegetative succession processes related to the Aral Sea shrinkage in the Eastern Cliff of the Ustyurt Plateau in Republic of Uzbekistan,Central Asia.We compared the results of our current investigation(2010–2017)on vegetative communities with the geobotany data collected during the 1970s(1970–1980).The results showed great changes in the mesophytic plant communities and habitat aridization as a result of the drop in the underground water level,which decreased atmospheric humidity and increased the salt content of the soil caused by the shrinkage of the Aral Sea.In the vegetative communities,we observed a decrease in the Margalef index(DMg),which had a positive correlation with the poly-dominance index(I-D).The main indications of the plant communities'transformation were the loss of the weak species,the appearance of new communities with low species diversity,the stabilization of the projective cover of former resistant communities,as well as the appearance of a new competitive species,which occupy new habitats.

莓叶委陵菜叶插繁殖技术研究

莓叶委陵菜(Potentilla fragarioidis)作为我国北方地区极具开发潜力的乡土地被植物,存在着有性繁殖材料不易获得且繁殖系数较低的问题。而扦插繁殖作为一种无性繁殖手段,能为莓叶委陵菜的快速繁殖提供新的途径。本研究以莓叶委陵菜生长健壮、无病虫害的叶为试验材料,通过正交试验针对不同扦插基质、激素种类及其浓度对莓叶委陵菜叶插生根效果的影响进行探究。结果表明,莓叶委陵菜插穗在扦插45 d后能够形成根系,不同处理水平的扦插基质、激素种类及其浓度间的交互效应对插穗生根效果的影响具有显著差异(P<0.05)。扦插基质是影响莓叶委陵菜叶插生根率的主导因子,而激素种类是影响平均单株生根数、平均单株总根长、最长根长和根系效果指数的主要因素。以草炭+珍珠岩+蛭石(1:1:1)为基质,扦插前使用300 mg·L^(-1)的IBA对插穗进行处理生根效果最佳,该处理方式下扦插生根率达63.33%,平均单株生根数为6.90条,平均单株总根长为27.98 cm,最长根长13.83 cm,根系效果指数达20.50。本研究结果可为莓叶委陵菜无性系繁殖体系的快速建立提供理论依据。

积雪变化对陆地生态系统植被特征和土壤碳氮过程的影响

在季节性积雪地区,冬季气候变暖导致积雪变薄、积雪不连续、融雪提前及雪盖面积缩小等现象。然而相较于氮沉降、增温、降水变化等全球变化因子,目前尚缺乏积雪因子对陆地生态系统过程和功能影响的系统报道。为加深人们对积雪特征变化生态后果的认知,综述了积雪深度和融雪时间变化对植被物候和群落组成、凋落物分解、土壤碳氮过程、温室气体排放和土壤微食物网(土壤动物和微生物)的影响。由于模拟积雪变化手段不同和复杂的气候、土壤背景,生态系统各要素对积雪特征变化的响应规律存在较大的分异和不确定性。例如,在未来气候变暖导致积雪变薄和融雪提前情景下,植被物候提前,生长季延长,导致生产力增加和凋落物数量增加,禾草比例减少导致凋落物质量增加,早春温度高刺激微生物活性,凋落物分解速率高,促进土壤碳氮周转过程。但积雪减少和融雪提前导致的早春低温和夏季干旱也可能引起植被生产力下降,凋落物数量减少质量降低,土壤微生物活性低,分解速率低,从而减缓碳氮周转过程。此外,积雪特征变化对植被特征和土壤碳氮过程影响相关研究目前还存在以下问题:1)积雪深度和融雪时间对生态系统的影响是否存在交互效应仍缺乏关注,且积雪变化对后续生长季是否存在持续效应也不明确;2)积雪因子对植被、土壤碳氮动态过程和土壤生物的影响,各生态要素研究相对较为独立;3)积雪变化引起对土壤地化循环过程影响的微生物驱动机制缺乏组学数据支撑;4)缺乏遥感手段反演各类影响生态系统功能和过程的积雪参数。应加强植被群落-土壤碳氮过程-土壤微食物网生态关联研究、基于基因组学的土壤微生物群落组成和生态功能研究和遥感相关技术研究,以期为发展积雪生态学提供参考。

高植被覆盖下铁路隧道口危岩落石风险评估

山区铁路选线受地形条件制约,高陡边坡或陡崖地段的隧道洞口常面临危岩落石风险,传统人工调查方法困难,尤其是高植被覆盖地区,受现场条件限制不能完全查明危岩分布,同时常用的落石运动轨迹模拟缺少横向范围控制,存在一定的安全隐患。以某铁路隧道进口工程为研究对象,以机载LiDAR和三维倾斜摄影数据为基础,查明了危岩形成机制及分布特征,利用自主研发的Rockfall Hunter软件分析不同破坏形式的危岩三维运动特征,并给出防护措施建议。研究表明:(1)基于定性分析和定量计算,建立的“数据、方法、意义”三阶段高植被覆盖区危岩落石风险综合评估方案行之有效;(2)利用精细化三维实景模型可准确提取危岩体几何信息,危岩落石发育区数字地表灰度影像表面坎坷不平、具粗糙感,危岩体截面地面点棱角显著、地势陡峭,原生孤石或滚石截面呈凸起状、有明显界限;(3)研究发现可能对工程造成危害的危岩体120处,总体积约15541 m^(3),以倾倒、坠落式破坏为主,局部发生组合式破坏;(4)落石进入隧址区最大速度为17.3 m/s,最大弹跳高度为12.5 m,最大冲击能量超过8000 kJ,建议采用避让、清理、加固等措施。

赣州市园林地被植物资源筛选评价及园林应用研究

为评价地被植物在赣州城市绿地中的表现,筛选出适合城市园林应用的地被植物品种,采用层次分析法构建赣州市园林地被植物综合评价体系,从观赏性、生物学特性、应用潜力3方面筛选出13个评价指标,对赣州市园林应用的75种地被植物进行评价与分级。结果表明:观赏期、显示度、适应性等指标在园林地被植物占较大权重,其中Ⅰ级(3.6<Q≤4.0)有9种,Ⅱ级(3.2<Q≤3.6)有29种,Ⅲ级(2.8<Q≤3.2)有25种,Ⅳ级(Q≤2.8)有12种。

洗煤厂皮带运输机抑尘罩的设计及应用

在煤炭加工领域,洗煤厂皮带运输机作为主要的煤炭输送设备,其运行过程中产生的粉尘对环境和工人健康构成潜在威胁。传统的抑尘罩存在防尘效果不佳和维护难度大等问题,因此有必要进行抑尘罩的设计和应用方面的深入研究。本篇文章旨在通过提出一种抑尘罩方案,优化现有抑尘措施,提高洗煤厂皮带运输机的抑尘效果,减少对环境的影响,提升生产设备的运行效率。

园林绿化景观建设中地被植物的选择与应用

在城市生态系统的建设中,地被植物是非常重要的组成部分。地被植物种类多,颜色风格各异,能够打造出完美的园林绿化景观。阐述园林绿化景观建设中地被植物的选择原则、选择方式、应用方法,为提高园林绿化景观的建设效果提供参考。

Floristic Diversity, Distribution and Analysis of Forest Cover Change in the Kedjom Keku Forest, NW Cameroon

Conservation of tropical rainforest is an important aspect of climate change mitigation, and baseline information through inventories of forests is paramount so as to enable the putting in place of proper management strategies. This study was aimed at evaluating the plant species diversity, and distribution and to investigate the forest cover change of the Kedjom Keku forest. Five plots were located at irregular intervals (100 m × 50 m) along a line transect and spread throughout the study area using 10 m × 10 m. Land cover/Land use changes were evaluated using remote sensing and GIS, while semi structured questionnaires were used to assess the anthropogenic activities. A total of 107 species of plants including 74 trees, 28 shrubs and 5 lianas, belonging to 83 genera and 58 families were identified. Rubiaceae (10 species) and Asteraceae (5 species) were the most represented tree and shrub families respectively. Species with the highest important value index were Schefflera mannii (31.9) and Piper capense (16.9) for trees and shrubs respectively. This forest is diverse, with Shannon-Wiener diversity index values of 3.55 for trees and 3.07 for shrubs. Seven land cover classes were distinguished within the years 1986, 2003 and 2018. There was a drastic increase in built up/settlement from 0.63% in 2003, to 20.46% in 2018. Dense vegetation increased within 2003 to 2018 after a drastic drop from 151.86 ha&#8722;1 to 119.88 ha&#8722;1 between 1986 and 2003. Infrastructure, over-grazing and expansion of farmland were reported as the direct factors influencing degradation, while land right, land tenure and equitability were the most cited indirect factors. The prominent factor that encouraged degradation was the fertile nature of the soils. We propose that sensitization campaigns be carried out to educate inhabitants on the rich biodiversity of Kedjom Keku forest and explain to them the importance of sustainable management of the resources therein.

栖龙湾土壤侵蚀影响因子分析

土壤侵蚀是导致生态环境恶化和土地生产力下降的主要原因,而坡度、降雨强度、降雨量和植物措施和工程措施是影响土壤侵蚀的重要因素。栖龙湾小流域以山地棕壤为主,以栖龙湾10个径流小区2008-2016年观测数据为基础,对土壤侵蚀因素和侵蚀量进行分析,得到了如下结论:①对于莱芜栖龙湾小流域,坡度对土壤侵蚀的影响并不明显。②在各个降雨量变化区间,土壤侵蚀量随坡度的增大增加,土壤侵蚀量并不是单一增长或减少的原因可能与溅蚀率有关。③3种类型径流小区土壤侵蚀量依次为:耕地小区>裸地小区>林地小区。④当降雨强度和降雨量较小时,无需大规模的采取水土流失防治措施;当降雨强度或降雨量较大时,板栗结合鱼鳞坑的水土保持措施效果更好。⑤植被覆盖度越高,土壤侵蚀量越小;植被覆盖度越低,土壤侵蚀量越大。

橡胶林土壤侵蚀地被植物的防控探讨

橡胶树为我国重要的经济林木,天然橡胶是重要的战略物资和工业原料,为植胶区农村农民收入的重要来源。本文阐述了橡胶林地被植物的土壤侵蚀防控能力,总结橡胶林地被植物防控是天然橡胶产业绿色发展的需要,分析了橡胶园地被植物种类、橡胶园间种经济作物对土壤可蚀性影响,提出橡胶林土壤侵蚀地被植物的综合防控建议。

Effect of Visual Stimuli of Indoor Floor Plants upon the Human Responses

The biophilia hypothesis maintains that animals, which bring benefits for human survival, evolve adaptively to cause a positive emotional response or actions in the human evolution process. When connected in an advantageous environment for survival, effective relaxation and recovery from fatigue are brought about as further physiological functions, rather than a simple stress-free situation. The aim of this study is to clarify the significance of the visual stimulation of indoor floor plants placed in an office floor space. We examined how the green covering factor and gaze distance to indoor floor plants placed on the floor influenced thermal sensation. The thermal environment conditions were set at 3 levels, 25&#176;C, 28&#176;C, and 31&#176;C and the floor and air temperature were homogenous. We set up 8 office floor plans that had no visual stimulation and used indoor floor plants including pachira, monstera, butterfly palm, yucca elephantipes, weeping fig, umbellate, and snake plant for a visual stimulation. The gaze distance, measured from the center of the subject presented with a visual stimulation and the center of the plant, was set at 3 distances: 2.0, 4.5 and 8.0 m. When the conduction-corrected modified effective temperature (ETF) was below 26&#176;C, the visual stimulation of the indoor floor plants umbellata and monstera, which have a silhouette with low leaf density and rounded leaves, were shown to mitigate the sensation of being cool. The visual stimulation of indoor floor plants with rounded leaves, such as, pachira, monstera, weeping fig, and umbellata, were shown to decrease the feeling of discomfort. For a gaze distance below 4.5 m, a green covering accounting for less than 5% was shown to be necessary for mitigating the sensation of being cool and improving the feeling of discomfort.