渝湛高速(广东段)边坡早期树林化试验分析

随着国民经济的发展，高速公路边坡绿化与当地环境相协调越来越受到重视，为使渝湛高速（广东段）公路边坡绿化达到早期树林化，本文采用在边坡铺二维网、三维网、椰丝毯以及采用客土喷播、灌草混播等试验．结果表明：铺椰丝毯能够使公路边坡达到早期树林化。     

高速公路岩石边坡客土喷播施工技术——以宁常高速公路南京段客土喷播为例

随着高速公路的快速发展,公路建设中山地开挖形成大量裸露的边坡,既破坏公路景观,又造成水土流失。客土喷播能在普通条件下无法绿化或绿化效果较差的岩石边坡上实现草灌结合,立体绿化,恢复自然植被。宁常高速公路南京标段岩石边坡坡度60°70°,平均高度20 m,板状石质,质地坚硬。结合该标段施工实例,论述了岩石边坡客土喷播所需材料和设备、施工流程和技术要点、验收要点和标准。实践证明,客土喷播绿化速度快、植被覆盖率高,是高速公路岩石边坡绿化的一种新方法。     

类芦绿化边坡施工方法的研究

随着经济和建设事业的迅猛发展,新修公路、铁路、新的建设场地的开挖,开矿山、采石场等,这些都会形成很多大面积裸露边坡。为了恢复自然植被,防止水土流失,需要及时将这些裸露边坡种草绿化,通常采用喷播机,将草子喷播到边坡上,实现绿化边坡的目的。但现有草种多从国外进口,如百慕达、画眉草、百喜草等,其存在的问题是国外的草种难以适应本地的土壤、气候条件,在边坡恶劣的环境条件下,当年绿化效果较好,经过2年后便退化、消失,绿化效果不能持     

有机基材喷播绿化技术在高速公路岩质边坡的应用

就高速公路岩质边坡有机基材喷播绿化的关键技术进行了概述,为克服当前我国高速公路岩质边坡绿化传流技术(一般方法)的不足,提高植被恢复效果提供了依据。从而也使我国高速公路的绿化走上一条“生态、经济和社会”效益三结合的可持续发展道路。     

有机基材喷播绿化技术在高速公路岩质边坡的应用

就高速公路岩质边坡有机基材喷播绿化的法)的不足,提高植被恢复效果提供了依据.从而也使我国高速公路的绿化走上一条"生态、经济和社会"效益三结合的可持续发展道路.     

客土喷播在潭邵高速公路石质边坡防护中的应用

介绍了潭邵高速公路石质边坡客土喷播生物防护技术的适应情况、施工工艺及工程试验情况,指出了这一防护技术与传统的边坡防护相比较,具有机械化程度高、施工安全、稳定表层边坡、成本低等优点,同时对极陡边坡(1∶0.3～1∶0.75)采用客土与植本地草皮相结合的办法,达到了满意的效果,造价仅为喷混植草的70%,且生长快,绿化效果更好.     

绵阳南郊机场专用道边坡绿化技术及防护效益的研究

根据立地条件和生物生态学特征,选用狗牙根(Cynodon dactylon)、百喜草(Paspalum notatum)、高羊茅(Festuca arundinacea)、多年生黑麦草(Lolium perenne)、结缕草(Zoysia japonica)和白三叶(Trifoliumrepens)在绵阳南郊机场专用道边坡绿化中按不同组合实施混播建坪。通过对密度、高度、盖度、生物量以及防护效果的系统观测,结果表明,在当地立地条件下,最适合以狗牙根和百喜草为主混播建植公路边坡植被。     

绵阳南郊机场专用道边坡绿化技术及防护效益的研究

根据立地条件和生物生态学特征,选用狗牙根(Cynodon dactylon)、百喜草(Paspalum notatum)、高羊茅(Festuca arundinacea)、多年生黑麦草(Lolium perenne)、结缕草(Zoysia japonica)和白三叶(Trifoliumrepens)在绵阳南郊机场专用道边坡绿化中按不同组合实施混播建坪.通过对密度、高度、盖度、生物量以及防护效果的系统观测,结果表明,在当地立地条件下,最适合以狗牙根和百喜草为主混播建植公路边坡植被.     

3种修复措施对高原高速公路边坡土壤化学计量特征的影响

探究不同修复措施短期内对高原高速公路边坡土壤化学计量特征的影响可以有效指导高原生态脆弱区生态系统的保护和恢复。为了比较3种高速公路边坡修复措施(自然恢复、补播草种+覆土处理、草皮回铺)的效果，测定了四川省阿坝藏族羌族自治州境内3种边坡修复措施处理和对照样地土壤有机碳(SOC)、全氮(STN)、全磷(STP)和全钾(STK)含量。结果表明：短期内，草皮回铺修复措施下的大部分化学计量特征，如SOC、STN和STP含量、SOC:STN、SOC:STP、SOC:STK、STN:STP、STN:STK和STP:STK均显著高于其他修复措施处理(P <0.05)。从土壤肥力角度出发采用土壤质量指数(SQI)对本研究所涉及的3种修复措施的修复效果进行评价，草皮回铺修复措施下的SQI高于其他两种修复措施的SQI，可见，草皮回铺修复措施是短期内高原地区公路边坡修复最佳的修复措施。     

洛湛铁路边坡稳定和绿化技术探讨

选用狗牙根Cynodon dactylon,百喜草Paspalam notatum,猫尾草Phleum pratense,高羊茅Festuca elata草种以达到稳定和绿化铁路边坡的目的.3-7月播种的草种能在短期内形成有效覆盖,当年覆盖率可达95%以上,狗牙根 百喜草混播及狗牙根 猫尾草混播革种生长好,绿期长,密度大对边坡的稳定防冲效果最佳.     

Echocardiographic study of the anesthetized cat.

Echocardiographic parameters were recorded, measured and statistically analyzed on a population of normal cats under pentobarbital anesthesia. Results of the study are similar to those obtained by previous investigators. However, this investigation demonstrates the depressant effect of pentobarbital anesthesia on cardiac contractility and the percent change in the left ventricular minor diameter. Analysis by correlation indices shows a positive relationship between the left ventricular diastolic and systolic dimensions, the left ventricular diastolic dimension and the E to F slope of the anterior mitral valve, the left ventricular systolic dimension and the E to F slope, the percent change in left ventricular minor diameter and the velocity of circumferential fibre shortening of the left ventricle and the left atrial dimension and body weight. A negative correlation exists between the left ventricular dimension at systole and the percent change in minor diameter of the left ventricle and the velocity of circumferential fibre shortening.     

不同微地形固定沙丘地上植被、土壤种子库和土壤含水量的分布特征

通过野外调查和室内培养的方法对盐池荒漠草原区不同微地形固定沙丘地上植被、土壤种子库和土壤含水量进行了调查,并研究了地上植被、土壤种子库和土壤含水量的空间分布特征及其关系以及微地形对土壤种子库及地上植被物种类型、物种密度、相似性和土壤种子库物种多样性的影响。结果表明,1)固定沙丘土壤种子库和地上植被物种数、密度、相似性、土壤种子库物种丰富度指数及土壤含水量、地上植被覆盖度和土壤种子库储量都呈现出底坡＞下部坡位＞中部坡位＞上部坡位＞顶坡的趋势,且土壤含水量、地上植被覆盖度和土壤种子库储量三者之间显著正相关(P0.05);2)土壤种子库物种多样性指数和均匀性系数随坡位变化呈现出波动状态。     

黄土塬边坡植被类型对土壤孔隙的影响

黄土塬边坡植被建设以固坡为目的,不同植被的土壤孔隙结构有利于增加降水入渗,从而减少坡面产流的水蚀危害。本研究以长武塬黄土塬边坡的侧柏(Platycladus orientalis)林地、沙棘(Hippophae rhamnoides)灌丛、草地和农地4种植被为研究对象,采集0–30 cm的原状土柱,利用CT扫描和图像处理技术,对其土壤孔隙度、孔隙数目、孔隙成圆率和孔隙分形维数进行定量分析,结合土层样品的理化性质,研究影响土壤孔隙结构的主要因素。结果表明,农地、侧柏孔隙的孔径大小分异不大,而草地、沙棘自身根系互动穿插生成的根孔扩展了孔径分布范围,不仅增加了孔隙度和大孔隙数目,也降低了孔隙成圆率。草地、沙棘有利于降水入渗,是固坡的优先选择。土壤有机质、粘粒含量等性质与孔隙参数之间具有极显著(P <0.001)或显著(P <0.05)相关关系,它们的改变对土壤孔隙特征变化和提高蓄水保土能力具有重要影响。     

Density-Dependent Ecohydrological Effects of Piñon–Juniper Woody Canopy Cover on Soil Microclimate and Potential Soil Evaporation

Many rangeland processes are driven by microclimate and associated ecohydrological dynamics. Most rangelands occur in drylands where evapotranspiration normally dominates the water budget. In these water-limited environments plants can influence abiotic and biotic processes by modifying microclimate factors such as soil temperature and potential soil evaporation. Previous studies have assessed spatial variation in microclimate and associated ecohydrological attributes within an ecosystem (e.g., under vs. between woody canopies) or across ecosystems (e.g., with differing amounts of woody canopy cover), but generally lacking are assessments accounting systematically for both, particularly for evergreen woody plants. Building on recently quantified trends in near-ground solar radiation associated with a piñon–juniper gradient spanning 5% to 65% woody canopy cover, we evaluated trends in soil temperature and associated estimates of potential soil evaporation as a function of amount of woody canopy cover for sites overall and for associated canopy vs. intercanopy locations. Quantified soil temperature trends decreased linearly with increasing woody canopy cover for intercanopy as well as canopy patches, indicating the coalescing influence of individual canopies on their neighboring areas. Notably, intercanopy locations within high-density (65%) woody canopy cover could be as much as ～10°C cooler than intercanopy locations within low-density (5%) cover. Corresponding potential soil evaporation rates in intercanopies within high-density woody canopy cover was less than half that for intercanopies within low density. Our results highlight ecohydrological consequences of density-dependent shading by evergreen woody plants on soil temperature and potential soil evaporation and enable managers to rapidly estimate and compare approximate site microclimates after assessing amounts of woody canopy cover. Such predictions of microclimate have general utility for improving management of rangelands because they are a fundamental driver of many key processes, whether related to understory forage and herbaceous species or to wildlife habitat quality for game or nongame species.     

Transverse and dorso-ventral changes in thoracic dimension during equine locomotion

Changes in shape of the equine thorax during locomotion are not well defined, although it has been shown recently that the transverse hemi-diameter changes its dimension by up to 80 mm on the side of the trailing forelimb during gallop, despite minimal change in thoracic circumference. The aim of this project was to analyse transverse and dorso-ventral changes in shape of the thorax simultaneously, and to determine if leading limb, treadmill slope and speed have an effect on these shape changes. Reflective markers were placed on the horse’s hemi-thorax and movement of the markers was recorded using a motion capture system while the horse trotted and cantered on a treadmill. Treadmill speed and slope, and the lead the horse cantered on were varied to determine the effects these had on transverse hemi-diameter and dorso-ventral diameter.There was a negative correlation between transverse and dorso-ventral changes in thoracic dimension, the strength of which increased with speed on the trailing limb side. On the leading side, the relationship was either weakly negative or positive. The changes in dimension of the hemi-thorax were significantly greater on the trailing side compared to the leading side. Speed had small effects on thoracic shape changes, but inclined exercise caused an increase in transverse hemi-diameter on the trailing side of the thorax. The changes in thoracic shape are unlikely to contribute substantially to ventilation and rib motion is likely to be due to protraction and retraction of the forelimbs. However, it may reflect asynchronous ventilation of lung lobes and partially explain the prevalence of exercise-induced pulmonary haemorrhage.     

浅析灌木与草本植物护坡效应

灌木与草本植物结合的护坡技术是解决保持水土、稳定边坡、美化环境等综合效益最佳的护坡途径之一.主要阐述了灌草植物护坡的条件和属种筛选依据,分析了灌草植物结合护坡的效应,并介绍了灌草植物结合护坡的组合搭配原则.     

The effects of topo-edaphic variables and cultivation on the woody vegetation of Weenen Nature Reserve,KwaZulu-Natal

The soil types and woody vegetation of Weenen Nature Reserve (WNR), KwaZulu-Natal, were described. Mispah, overlying shale, and Shortlands, overlying dolerite were the most common of 18 the soil forms encountered. Six vegetation types were identified by TWINS PAN which differed in slope, aspect, land-use history, species richness and tree density. Vegetation types ranged from species-rich, dense 'Coddia rudis-Dombeya cymosa Closed Woodland' overlying dolerite and occurring on steep north-east facing slopes that had never been cultivated, to previously cultivated, species-poor 'Acacia sieberiana Open Woodland' on flat topography, overlying shale. Ordination analyses further described the main associated floristic-environmental gradient from steep slopes supporting a high diversity of broad leaved species through to species-poor, flatter areas with an abundance of microphyllous plants. A second main gradient described was from uncultivated sites on steep slopes of usually dolerite-derived soils through to flat, previously cultivated land on shallow soils overlying shale. Topo-edaphic variables and previous cultivation, which were confounded, were therefore the main determinants of floristic variation in WNR, whereas fire had no influence. Half of the dominant woody species exhibited a reverse-J size structure, indicating relatively constant population change. A number of species had a preponderance of individuals in the smallest (0.5–1.5m height) size class, owing possibly to recruitment during the exceptional wet season of 1995/6, and/or the inability of individuals to escape the 'fire-trap'. Several, mostly Acacia, species appear to have recruited intermittently. The vegetation changes of this system will have an affect on browse availability. The woody vegetation of WNR appears to be changing in response to successional processes and management influences.     

黄土丘陵区不同恢复年限草地土壤微团粒分形特征

运用分形理论研究黄土丘陵区不同恢复年限草地土壤微团粒的粒径组成、分形维数特征及与土壤理化性质关系,使分形学在土壤微团粒性状与土壤肥力特征研究中得到进一步应用,并为评价草地生态系统土壤特征及生态恢复提供新方法。结果表明:表土层分形维数随植被恢复年限的增加而减少;剖面土壤沙粒含量越高,微团粒分形维数越低,粘粒规律相反,而粉粒与分形维数相关性不显著;土壤质地由粗到细使得分形维数由小到大变化;分形维数也可有效地表征不同植被恢复年限的草地土壤结构和养分的变化趋势;分形维数与土壤容重、非活性孔度、全磷、速效钾及氨态氮之间存在正相关性,与土壤活性孔度、孔隙比、有机质、全氮、碱解氮及硝态氮表现出负相关。     

添加杨柳树枝对沙化土壤有机碳、含水量及微生物活性的影响

以宁夏银川腹部的沙化土壤为研究对象,设计了添加杨树粉碎材料（B）、添加杨树粉碎材料＋覆盖柳树枝条（C）和覆盖树枝混合粉碎材料（D）3种方式进行沙化土壤的处理,并以不做任何处理的土壤（A）为对照,测定了土壤中有机碳含量、含水量、微生物数量和酶活性。结果表明,B、C和D处理措施均能显著提高土壤含水量、有机碳含量、微生物（细菌、真菌和放线菌）数量(P＜0.05),其中细菌和放线菌数量增加最明显。B和C处理能显著增加土壤中脲酶和过氧化氢酶的活性(P＜0.05),D处理土壤中脲酶活性小于对照,过氧化氢酶活性与对照土壤无显著差异（P＞0.05）。相关性分析表明,土壤含水量、有机碳含量和细菌、真菌、放线菌数量以及脲酶、过氧化氢酶活性相关性显著(P＜0.05)。可见,添加有机物对修复沙化土壤、增加土壤微生物活性有显著作用。