共查询到19条相似文献，搜索用时 245 毫秒
1.
煤矸石是我国工业排弃数量最大的固体废弃物，它带来的危害是压占土地，破坏景观，污染环境，山西省作能源重化工基地，煤矸石的堆积，污染问题万为突出，改造任务异常艰巨。 相似文献
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通过对阜新海州矿区煤矸石堆积地植物群落的调查、土壤剖面的测定及土壤理化性状的分析,将海州矿区煤矸石堆积地划分为风化良好、风化中等、风化较差3类矸石土,并分析总结了3类不同矸石土的物理性状及群落分布的特性,在此基础上,研究其立地条件适宜的主要造林树种,旨在为矿区生态恢复和区域环境的改善提供科学的理论依据。 相似文献
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山西省西山矿区是全国重要的煤炭生产基地,每年产生数以万吨计的煤矸石。这些煤矸石长期堆积而成山,常常自燃,释放出大量有害气体,严重污染环境,破坏自然景观,影响人们身体健康,是矿区的一大公害。2006年山西省为彻底改善生态环境,启动了六大造林绿化工程,矸石山绿化作为全省煤 相似文献
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藤本植物在煤矸石山绿化中的应用 总被引：4，自引：0，他引：4
煤矸石山不仅侵占大量土地,污染环境,而且严重破坏生态景观,煤矸石山的绿化势在必行。选择藤本作为先锋植物绿化煤矸石山具有多种优势,但必须坚持适应性、生态性、节水性和经济性的原则。最后列举了常用先锋藤本植物种类。 相似文献
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对抚顺西露天矿煤矸石山表层煤矸石风化母岩进行多点取样,把风化物筛分成＞2mm、2mm ～0．05mm和＜0．25mm 3个粒级,分析测定了矸石山表层母岩及其风化物不同粒级中总有机碳含量,比较了表层矸石不同粒级风化物总有机碳的含量差异。结果表明：矸石山表层风化物总有机碳在53．1～84．7g＆#183;kg -1之间,母岩总有机碳在4．5～23．6g＆#183;kg -1之间。页岩风化物＜0．05mm粒级总有机碳含量最高,均值为118．4mg ＆#183; kg -1;燃后矸石风化物在＜0．05mm 粒级中有机碳含量次之,均值为108．8 mg ＆#183; kg -1。随着风化物颗粒减小,表层矸石风化物总有机碳含量有逐渐升高的趋势。 相似文献
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矿区废弃的煤矸石严重影响和污染矿区及其周边地区的生态环境,笔者介绍了霍州市团柏煤矿概况,对该矿煤矸石山的绿化治理现状进行了调查,根据5 a的造林实践经验,提出了采用火炬树、刺槐等根系发达、萌蘖性强、抗干旱瘠薄的树种;整地方式以穴状整地为主,并异地回填种植土;应加强浇水、施肥等抚育管理力度这一系列煤矿矸石山绿化技术,为矿区煤矸石造林绿化提供参考依据. 相似文献
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Silvopastoral systems may overyield compared to monocultures as a result of higher resource capture and/or facilitation effects
of the trees on the pastures. Festuca pallescens (St. Ives) Parodi, a forage species of Patagonia, is vulnerable to water deficit, suggesting that it may benefit from the
facilitative effects of trees. Radiation (PPFD), temperature, relative humidity (RH) and soil water distribution during the
growing season were measured under different tree cover levels in ponderosa pine-based silvopastoral systems. PPFD decreased
with increasing tree cover, and the decrease was lower in the positions under than between tree crowns. No significant differences
were observed for temperature, RH nor for soil water content between treatments. Pre-dawn water potential of grasses during
the growing season showed similar high values in all treatments. However, cumulative water stress was slightly lower in high
tree cover treatments than in open situations. Leaf water potential of the grasses during the day was always lower in open
grassland than in forested plots. The growth of the grasses showed no significant differences between treatments, but mean
growth tended to decrease in the more densely planted treatments. We concluded that F. pallescens is a species that is biologically sound for use in silvopastoral systems, because the balance between facilitation and competition
can be positive under the semiarid conditions of Patagonia. 相似文献
12.
Biologists have long been puzzled by the striking morphological and anatomical characteristics of Neotropical savanna trees which have large scleromorphic leaves, allocate more than half of their total biomass to belowground structures and produce new leaves during the peak of the dry season. Based on results of ongoing interdisciplinary projects in the savannas of central Brazil (cerrado), we reassessed the validity of six paradigms to account for the water economy of savanna vegetation. (1) All savanna woody species are similar in their ability to take up water from deep soil layers where its availability is relatively constant throughout the year. (2) There is no substantial competition between grasses and trees for water resources during the dry season because grasses exclusively explore upper soil layers, whereas trees access water in deeper soil layers. (3) Tree species have access to abundant groundwater, their stomatal control is weak and they tend to transpire freely. (4) Savanna trees experience increased water deficits during the dry season despite their access to deep soil water. (5) Stomatal conductance of savanna species is low at night to prevent nocturnal transpiration, particularly during the dry season. (6) Savanna tree species can be classified into functional groups according to leaf phenology. We evaluated each paradigm and found differences in the patterns of water uptake between deciduous and evergreen tree species, as well as among evergreen tree species, that have implications for regulation of tree water balance. The absence of resource interactions between herbaceous and woody plants is refuted by our observation that herbaceous plants use water from deep soil layers that is released by deep-rooted trees into the upper soil layer. We obtained evidence of strong stomatal control of transpiration and show that most species exhibit homeostasis in maximum water deficit, with midday water potentials being almost identical in the wet and dry seasons. Although stomatal control is strong during the day, nocturnal transpiration is high during the dry season. Our comparative studies showed that the grouping of species into functional categories is somewhat arbitrary and that ranking species along continuous functional axes better represents the ecological complexity of adaptations of cerrado woody species to their seasonal environment. 相似文献
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Lloyd J Bird MI Vellen L Miranda AC Veenendaal EM Djagbletey G Miranda HS Cook G Farquhar GD 《Tree physiology》2008,28(3):451-468
To estimate the relative contributions of woody and herbaceous vegetation to savanna productivity, we measured the 13C/12C isotopic ratios of leaves from trees, shrubs, grasses and the surface soil carbon pool for 22 savannas in Australia, Brazil and Ghana covering the full savanna spectrum ranging from almost pure grassland to closed woodlands on all three continents. All trees and shrubs sampled were of the C3 pathway and all grasses of the C4 pathway with the exception of Echinolaena inflexa (Poir.) Chase, a common C3 grass of the Brazilian cerrado. By comparing the carbon isotopic compositions of the plant and carbon pools, a simple model relating soil delta 13C to the relative abundances of trees + shrubs (woody plants) and grasses was developed. The model suggests that the relative proportions of a savanna ecosystem's total foliar projected cover attributable to grasses versus woody plants is a simple and reliable index of the relative contributions of grasses and woody plants to savanna net productivity. Model calibrations against woody tree canopy cover made it possible to estimate the proportion of savanna productivity in the major regions of the world attributable to trees + shrubs and grasses from ground-based observational maps of savanna woodiness. Overall, it was estimated that 59% of the net primary productivity (Np) of tropical savannas is attributable to C4 grasses, but that this proportion varies significantly within and between regions. The C4 grasses make their greatest relative contribution to savanna Np in the Neotropics, whereas in African regions, a greater proportion of savanna Np is attributable to woody plants. The relative contribution of C4 grasses in Australian savannas is intermediate between those in the Neotropics and Africa. These differences can be broadly ascribed to large scale differences in soil fertility and rainfall. 相似文献
14.
大红山铁矿林草植被水土保持效益的研究 总被引：2，自引：0，他引：2
以裸地为对照,分别对土壤物理性状及土壤的渗透性,土壤中含水量的动态变化,地表径流及土壤流失量等进行了定点定量观测。研究结果表明,林地与草地能有效改善土壤物理性状、增强土壤渗透性和降低土壤水分含量;能通过提高土壤抗蚀性、改善土壤养分含量来充分发挥水土保持效益。研究结果还表明,林地和草地减少侵蚀效益较好,裸地的土壤流失最严重。与裸地相比,林地和草地对地表径流的控制率达到63%～89%,对土壤流失的控制率达到69%～94%。 相似文献
15.
元谋干热河谷8种植被类型的林地土壤特性研究 总被引：7，自引：7，他引：7
通过对元谋干热河谷区加勒比松人工林、加勒比松 车桑子人工混交林、山合欢天然更新林、车桑子 山毛豆人工混交林、桉树人工林、草地、荒坡、膨胀土8种植被类型林地1 m土层内不同层次雨季(8月2日~9月2日)土壤水分含量的分析研究得出:在雨季8种植被类型林地土壤的水分含量均较低,因其土壤的物理性能较差,故蓄水保水能力也较差;各植被类型林地土壤的有机质、养分含量均极低,按照土壤养分含量分级标准,各植被类型林地土壤的养分含量均在6级以下。元谋干热河谷区林地土壤的贫瘠特性致使林木长势较弱,是造成其植被恢复困难的一个原因。 相似文献
16.
《Scandinavian Journal of Forest Research》2012,27(1-4):21-29
Piles of logging residues (slash‐piles) are a consequence of modem logging techniques. The piles cover 10 to 15% of a clear‐felled area. The effect of slash‐piles on nitrogen leaching was estimated by collecting precipitation1 and percolating water below slash‐piles and below the O, E and B horizons of an Orthic Podzol during two growing seasons. Open funnels were used for precipitation, PVC troughs for water leaving the pile and filled‐in zero tension lysimeters for percolating soil water. Exchangeable ammonium and nitrate of humus samples were analysed. The increased nitrogen leaching from the soil below slash‐piles was probably caused by an increased mineralization of the humus layer and a reduced nitrogen uptake by roots. 相似文献
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为了寻找促进干旱半干旱沙区抗旱造林的新途径,文章在野外自然条件下,对新型抗旱造林产品-"春之霖"固体水进行了应用研究。结果表明,虽然固体水处理后不同苗木不同土层土壤含水量变化不同,但缓慢释放的固体水主要集中在植物根系附近,提高根系层含水量,明显改善苗木的水分状况,减轻水分胁迫。使用固体水的供试苗木成活率均在90%以上,其中沙柳和杨树的成活率分别比对照高于12.5%和14.2%。经固体水处理后的苗木净高生长量、地上生物量、地下生物量均高于对照,固体水附近苗木侧根分布量最多。 相似文献
18.
Belowground interactions for water between trees and grasses in a temperate semiarid agroforestry system 总被引：1，自引：0，他引：1
María Elena Fernández Javier Gyenge Julian Licata Tomás Schlichter Barbara J. Bond 《Agroforestry Systems》2008,74(2):185-197
A fundamental hypothesis of agroforestry is the complementary use of soil resources. However, productivity of many agroforestry
systems has been lower than expected due to net competition for water, highlighting the need for a mechanistic understanding
of belowground interactions. The goal of this study was to examine root–root interactions for water in a temperate semiarid
agroforestry system, based on ponderosa pines and a Patagonian grass. The hypotheses were: (a) A greater proportion of water
uptake by pines is from deeper soil layers when they are growing with grasses than when they are growing alone; (b) Growth
of grasses is improved by the use of water hydraulically lifted by pines. We used stable isotopes of O to analyze water sources
of plants, and we measured sapflow direction in pine roots and continuous soil water content with a very sensitive system.
We also installed barriers to isolate the roots of a set of grasses from pine roots, in which we measured water status, relative
growth and water sources, comparing to control plants. The results indicated that pines and grasses show some complementary
in the use of soil water, and that pines in agroforestry systems use less shallow water than pines in monoculture. We found
evidence of hydraulic lift, but contradicting results were obtained comparing growth and isotope results of the root isolation
experiment. Therefore, we could not reject nor accept that grasses use water that is hydraulically lifted by the pines, or
that this results in a positive effect on grass growth. This information may contribute to understand the complex and variable
belowground interactions in temperate agroforestry. 相似文献
19.
By influencing belowground processes, streamside vegetation affects soil processes important to surface water quality. We
conducted this study to compare root distributions and dynamics, and total soil respiration among six sites comprising an
agricultural buffer system: poplar (Populus × euroamericana‘ Eugenei), switchgrass, cool-season pasture grasses, corn (Zea
mays L.), and soybean (Glycine max (L.) Merr.). The dynamics of fine (0--2 mm) and small roots (2--5 mm) were assessed by
sequentially collecting 35 cm deep, 5.4 cm diameter cores from April through November. Coarse roots were described by excavating
1 × 1 × 2 m pits and collecting all roots in 20 cm depth increments. Root distributions within the soil profile were determined
by counting roots that intersected the walls of the excavated pits. Soil respiration was measured monthly from July to October
using the soda-lime technique. Over the sampling period, live fine-root biomass in the top 35 cm of soil averaged over 6 Mg
ha-1 for the cool-season grass, poplar, and switchgrass sites while root biomass in the crop fields was < 2.3 Mg ha-1 at its maximum. Roots of trees, cool-season grasses, and switchgrass extended to more than 1.5 m in depth, with switchgrass
roots being more widely distributed in deeper horizons. Root density was significantly greater under switchgrass and cool-season
grasses than under corn or soybean. Soil respiration rates, which ranged from 1.4--7.2 g C m-2 day-1, were up to twice as high under the poplar, switchgrass and cool-season grasses as in the cropped fields. Abundant fine roots,
deep rooting depths, and high soil respiration rates in the multispecies riparian buffer zones suggest that these buffer systems
added more organic matter to the soil profile, and therefore provided better conditions for nutrient sequestration within
the riparian buffers.
This revised version was published online in June 2006 with corrections to the Cover Date. 相似文献