【作者】 马勇；

【导师】 刘金平；

【作者基本信息】 西华师范大学 ， 森林保护学， 2022， 硕士

【摘要】 紫色土丘陵区为典型亚热带季风气候的生态脆弱区,受自然因素和人为因素的影响,极易形成难以自然恢复的裸露边坡。常通过建植集绿化美化和生态功能一体的护坡草坪进行裸露边坡植被修复与重建。试验以同一地点,3个不同坡向（阴坡WN 29°、阳坡WS 33°、半阴坡EN 40°）上由高羊茅（Festuca arundinacea）、多年生黑麦草（Lolium perenne）和草地早熟禾（Poa pratensis）1:1:1按3粒·cm^-2建植的冷季型混播边坡草坪为对象,研究坡向对群落特征、草坪草重要值和草坪品质及护坡土壤的影响,探究坡向影响草坪群落特征及草坪结构、功能及寿命的原因,以期筛选出适合不同坡向边坡草坪建植与养护技术,为裸露边坡生态植被恢复、增加边坡景观效益、预防草坪退化及植物群落功能评价提供依据与借鉴。为建设与改善城市整体环境,提高城、林、水一体化的城市森林生态系统作出贡献。主要结果如下:1)坡向显著影响草坪群落特征参数（P<0.05）,第2～5年半阴坡群落密度大于阳坡和阴坡,第2～4年阴坡基盖度显著大于半阴坡和阳坡,第1～5年中阳坡物种密度大于半阴坡和阴坡,随年限增加阳坡物种密度和优势种高度高于半阴坡和阴坡,群落密度和基盖度越来越低于半阴坡和阴坡。坡向影响为优势种高度＞物种密度＞群落密度＞基盖度,坡向和年限共同作用影响着群落组成和演替潜力。2)坡向显著影响3种草坪草群落比例、相对密度和重要值（P<0.05）,3种草坪草比例逐年下降,2～3年相对密度和重要值下降最快,阳坡退化速度高于半阴坡和阴坡。坡向对重要值影响为相对密度＞相对频度＞相对盖度,对草种影响为多年生黑麦草＞高羊茅＞草地早熟禾。第1～2年阴坡上草坪植物重要值大于半阴坡和阳坡,第3～5年阳坡上重要值大于半阴坡和阴坡（P<0.05）。3)坡向显著影响草坪草的生长情况与生物量（P<0.05）,坡向对绝对生物量和相对生物量影响为草地早熟禾＞多年生黑麦草＞高羊茅;阳坡高羊茅绝对生物量大于半阴坡和阴坡,阴坡多年生黑麦草和草地早熟禾相对生物量大于半阴坡和阳坡（P<0.05）。第2～3年单株生物量增加而4～5年下降（P<0.05）,阳坡利于高羊茅生长,阴坡则利于多年生黑麦草和草地早熟生长。坡向对根冠比影响为高羊茅<多年生黑麦草<草地早熟禾,阳坡3种草坪植物的根冠比大于半阴坡和阴坡。4)坡向显著影响草坪重要值和生物量的退化速率和退化表现,坡向对相对密度、相对频度和相对盖度退化速率均有影响,重要值退化速率为多年生黑麦草＞总值＞高羊茅＞草地早熟禾,相对生物量退化速率均为草地早熟禾＞多年生黑麦草＞总值＞高羊茅。第2年阳坡黑麦草和早熟禾相对生物量退化速率为74.81%和86.13%,第4年阴坡高羊茅相对生物量退化速率为70.16%。坡向和年限共同作用使边坡草坪2～3年严重退化。草坪质量指标中的密度、质地、颜色、均一性不断下降,虽杂草入侵一定程度上增加盖度与强度,但护坡草坪整体质量优良度不断下降,最终由轻度退化演替为重度退化。5)坡向对土壤理化性状有显著影响（P<0.05）,坡向对粒级组成影响为大砂粒＞细粉粒＞极细砂粒＞粗沙粒＞粘粒＞粗粉粒＞细砂粒,阳坡的粘粒、细粉粒、粗粉粒、大砂粒低于阴坡和半阴坡,第5年3个坡向土壤的粘粒、细粉粒、粗粉粒、极细砂粒和细砂粒显著大于第1年。阴坡的有机质、有效N、有效P、有效K均显著大于阳坡,半阴坡的有效P、有效K与阴坡几乎无差异。护坡草坪均显著提高了3个坡向土壤中粘粒、粉粒比例,增加了边坡的土层厚度,降低了土壤容重,提高了土壤有机质有效N、有效P、有效K的含量。综上,坡向显著影响草坪群落特征、建群种重要值、退化速度和品质优良度,控制杂草入侵是防止护坡草坪退化的有效途径,建植草坪显著提升了护坡土壤质地和供水供肥能力。故依坡向选择配置草种、制定建植和养护技术、加强杂草管理和维持草坪先锋植被功能,是裸露边坡生态治理与构建护坡植被稳定功能的基本要求。更多还原

【Abstract】 Purple soil hilly area is a typical subtropical monsoon climate ecological fragile area.Due to the influence of natural and man-made factors,bare slopes that difficult to recover naturally were often formed.In order to realize the functions of afforestation and beautification and ecological integration,slope protection lawn was often built on bare slopes for vegetation restoration and reconstruction.However,the spatial distribution of solar radiation and precipitation was seldom considered,which changes the distribution of water and nutrients in slope soil,resulting in heterogeneity of water,fertilizer,air,heat,light and other habitat factors on different slope slopes,which affects the growth of turfgrasses and the stability and ecological function of the communities.In the study,the cold-season mixed-sown lawn which sown by Festuca arundinacea,Lolium perenne and Poa pratensis on three slope directions(semi-shading slope EN 40°,sunny slope WS33°,shady slope WN 29 °)of same location in purple soil hilly area was used as the research object.After 1-5 years of construction,continuously measured the community characteristic parameters such as species density,dominant plant species and height,community density and base coverage of lawn community,and determined the dominance parameters such as relative frequency,relative coverage and relative density of three lawn grasses.At the same time,it also measured the growth parameters such as plant individual and population biomass,and the quality parameters such as color,coverage and uniformity,meanwhile measured soil particle size composition and soil p Hysical and chemical properties.The purpose of all the measurements was to analyze the succession and change rule of slope-plant-vegetation-soil-function relationship,and to study the effects of slope direction on community characteristics,turfgrasses important value and turf quality and slope soil.Then explore the reasons why the slope direction affects the community characteristics and the structure,function and service life of lawn,in order to screen out the planting and maintenance technologies suitable for different slope directions.It provided a basis and reference for bare slope ecological vegetation restoration,increasing slope landscape benefits,preventing lawn degradation and plant community function evaluation.To contributed the construction and improvement of the city’s overall environment and improved the city’s forest ecosystems integrated with cities,forests and water.The main results are as follows.1)Slope direction significantly affected the characteristic parameters of lawn community(P < 0.05).The community density of semi-shady slope was higher than that of sunny and shady in 2-5 years,and the base coverage of shady slope was significantly higher than semi-shady and sunny in 2-4 years,but the species density of sunny slope was higher than semi-shady and shady in 1-5 years.With the increase of years,the species density and dominant species height on sunny slope were higher than semi shady and shady,and the community density and base coverage were lower and lower than semi-shady and shady slope.The influence of slope direction was dominant species height ＞ species density ＞ community density ＞ base coverage.Slope direction and years affected community composition and succession potential.2)Slope direction significantly affected the communities proportion,relative density and important value of three turfgrass(P < 0.05).The proportion of three turfgrass decreased year by year,the relative density and important value decreased fastest in 2-3 years,and the degradation rate of sunny slope was higher than semi-shady and shady.The effect of slope direction on relative value was relative density ＞ relative frequency ＞ relative coverage,and on grass species was L.perenne ＞ F.arundinacea ＞ P.pratensis.The important value of the turfgrasses on shady slope in 1-2 years was greater than that on semi-shady and sunny,and that on sunny slope in 3-5 years was greater than semi-shady and shady(P < 0.05).3)Slope direction significantly affected the growth and biomass of turfgrass(P <0.05).The effects of slope direction on absolute and relative biomass were P.pratensis ＞ L.perenne ＞ F.arundinacea.The absolute biomass of F.arundinacea on sunny slope was greater than semi-shady and shady,and the relative biomass of L.perenne and P.pratensis on shady slope was greater than semi-shady slope and sunny(P < 0.05).The biomass per plant increased from 2 to 3 years and decreased from 4 to 5 years(P < 0.05).The sunny slope was conducive to the growth of F.arundinacea,while the shady slope was conducive to the early growth of L.perenne and P.pratensis.The effect of slope direction on root/shoot ratio was F.arundinacea＞L.perenne ＞ P.pratensis,and the root/shoot ratio of 3 turfgrasses on sunny slope was larger than semi-shady and shady.4)The slope direction significantly affected the degradation rate and degradation performance of turfgrasses important value and biomass.The slope direction had a significant effect on relative density,relative frequency and relative coverage degradation rate.The degradation rate of important value was L.perenne ＞ total value ＞ F.arundinacea ＞ P.pratensis,and the degradation rate of relative biomass was P.pratensis ＞ L.perenne ＞ total value ＞ F.arundinacea.As L.perenne and P.pratensis had 74.81 % and 86.13 % degradation rate in the 2nd year on sunny slope,but F.arundinacea had 70.16 % degradation rate on shady slope in 4th year.The slope direction and service year together make the slope lawn seriously degraded in 2-3years.The density,texture,color and uniformity of quality indexes decreased continuously.Although weed invasion increased the coverage and intensity to a certain extent,the overall quality excellence decreased continuously,and finally changed from mild degradation to severe degradation.5)Slope direction had significant effect on soil p Hysical and chemical properties(P < 0.05).The effect on particle size composition was large sand ＞ fine silt ＞ very fine sand ＞ Coarse Sand ＞ clay ＞ coarse silt ＞ fine sand.The clay,fine silt,coarse silt and large sand on the sunny slope are lower than those on the shady and semi-shady slope.The clay,fine silt,coarse silt,very fine sand and fine sand of three slopes soil in the fifth year were significantly greater than those in the first year.The organic matter,effective N,effective P and effective K of the shady slopes were significantly higher than sunny slopes,but the effective P and effective K of semi-shady slopes were not different from those of shady slopes.The slope protection lawn significantly increased the proportion of clay and silt in the soil in the three slope directions,increased the soil thickness of the slope,reduced the soil bulk density,and increased the contents of available N,available P and available K of soil organic matter.In summary,the slope direction significantly affects the characteristics of lawn community,the important value of established species,the degradation speed and quality excellence of lawn.Controlling weed invasion was an effective way to prevent the degradation of the lawn.The lawn establishment significantly improves the soil texture and water and fertilizer supply capacity of slope soil.Therefore,it is the basic requirement of ecological management and construction of slope protection vegetation to select grass species,establish planting and maintenance techniques,strengthen weed management and maintain pioneer vegetation functions.更多还原