共查询到20条相似文献，搜索用时 78 毫秒
1.
矿区废弃矿地面临的主要生态学问题是表土层破坏,选取优良的先锋物种进行植被恢复对矿废弃地表层土修复和加快生态演替起着关键作用.本文以梅州市平远县仁居稀土矿为例,调查香根草作为先锋植物在稀土矿废弃地生态演替情况以及实验分析得出不同植物群落下的土壤侵蚀模数和土壤理化性质,通过实地调查和实验得出香根草在稀土矿废弃地的植被恢复过程中加快了生态演替速度,具有护坡、固土、涵养水源、改善土壤理化性质的作用,但氮磷钾的含量较低,肥力较差.讨论得出增施肥料,培育壮苗是香根草植被修复的关键措施,利用多物种相结合方式加快稀土矿废弃地植被恢复,促进生态演替. 相似文献
2.
种群密度制约原理在生态恢复中应用的思考 总被引：2，自引：0，他引：2
俞筱押 《黔南民族师范学院学报》2007,27(3):31-33,82
种群密度制约是种群自我调节的重要机制，是生态学的重要原理之一，而且被列为恢复生态学的重要原理之一。现有资料表明：该原理在国内的研究多处于证明阶段，缺乏实际应用。本文分析了不同生态恢复途径下如何应用种群密度制约原理，认为：在人工重建生态系统时，应该注意种群的合理密度；在实施自然恢复的生态系统中，应该增加人类活动的积极干扰，控制植物种群的密度，使植被得以快速恢复。 相似文献
3.
广西石漠化地区不同植被恢复样地的土壤微生物量比较 总被引：1，自引：0，他引：1
用土壤微生物研究方法和化学分析方法,对广西石漠化地区不同植被恢复样地土壤微生物量碳、氮和磷以及土壤呼吸速率进行测定,从不同植被类型及土壤理化性质等角度,对不同植被恢复调查样地的生态恢复效果进行比较。结果表明:土壤微生物量碳、磷以及土壤呼吸在不同植被样地之间有显著差异;土壤微生物量碳的大小排序为:乔灌混交林青檀任豆青冈侧柏阴香青檀+鞍叶羊蹄甲剑麻枫香湿地松吊丝竹湿地松+桉树桉树光板地;在一定时间范围内,随着植被恢复年限增加,土壤微生物量碳含量逐渐增加,土壤微生物量氮也呈现缓慢增加,但土壤微生物量磷却呈现明显的波动性,出现先升后降现象;土壤微生物量与土壤水分、有机质、含氮量、脲酶活性等土壤肥力因子有较好的相关性;以青檀、侧柏、阴香、任豆等乡土植物为优势种的样地,其土壤微生物量明显大于外来物种湿地松和桉树为优势种的样地。因此,在石漠化地区植被恢复过程中,应首先考虑使用青檀、侧柏、阴香、任豆等乡土树种。 相似文献
4.
煤矿废弃地造成的土壤重金属污染是一个关键性的问题;采煤区沉陷导致地表植物被破坏,植被覆盖率降低;采煤过程会导致周边土壤污染,影响土壤中微生物群落.而丛枝菌根真菌能与植物形成共生体,在增加土壤养分、增强植物耐受力以及修复重金属污染方面具有良好的效果.探讨了近年来国内外丛枝菌根真菌对煤矿废弃地如Cd等重金属污染、烃类有机化学物质污染的修复和植物生长的促进作用,以期为未来研究提供一定的思路和理论基础. 相似文献
5.
蔡深文 《遵义师范学院学报》2015,(1):106-110
金属型植物能够在重金属污染严重的土壤中生存和繁殖,一方面可以通过避性机制减少对环境中重金属的吸收,另一方面通过耐性机制,如细胞壁结合、区室化作用、螯合作用和抗氧化机制减小过量蓄积在体内的重金属产生的毒害作用。金属型植物是植物修复土壤重金属污染的理想材料。深入研究金属型植物的抗性机制,可为重金属污染地区的植被恢复和生态恢复提供理论依据,对于土壤重金属污染的治理将起到十分重要的作用。 相似文献
6.
退化岩溶生态地区植被恢复对土壤化学性质的影响——以石林地区为例 总被引：1，自引：0，他引：1
以石林喀斯特地区植被恢复过程中典型样地为研究对象,选择了草从、灌草丛、次生林、原生林、人工林和玉米耕地六种植被类型的土壤PH值,有机碳,全氮含量与C/N比进行了分析比较。结果显示：植被恢复程度越高,土壤PH值就越小,而土壤有机质含量越高;人工造林与植被自然恢复相比,植被自然恢复更有利于土壤质量的改善和植被的生长;耕地与其它样地相比,在退化岩溶生态系统地区,人类活动与不合理利用土地都会使土壤质量受到严重影响。因此,我们平时要注意对喀斯特地区的植被保护,特别是石漠化严重的地区,要严厉禁止人为再次干扰,使各种植被更快更好地恢复起来。 相似文献
7.
石灰岩地区是中国生态环境脆弱的地区之一,由于其脆弱的自然地质环境和人为活动的强烈影响,石灰岩生态环境的恢复一直是研究的热点.随着研究水平提高和科学技术以及其他各个学科的发展,生态系统理论在石灰岩植被恢复过程中的应用也日渐增多.针对石灰岩地区生态系统的脆弱性综述了石灰岩植被恢复的生态系统理论,分析了各个生态系统理论在石灰岩植被恢复过程中的应用,并提出植被恢复和重建的技术途径. 相似文献
8.
吴锦礼 《中国科教创新导刊》1996,(10)
世界最大种子库保藏着植物群的未来一满袋干燥的种子可能不如熊猫或小海豹那么起眼。但它们对于地球的未来却具有重大作用。在英国萨塞克斯郡韦克赫斯特地方由克尤皇家植物园的专家们管理的世界上最大的种子库中，现已收藏了２．５亿粒种子，这些种子被储存于可使它们在数... 相似文献
9.
10.
11.
12.
13.
《海外英语》2007,(5):10-11
Many college freshmen arrive woefully unprepared to do college work, and as disadvantaged populations continue to grow, the share of the American work force that has made it through college is expected to plummet. Many experts blame that educational failure not just on high schools but also on colleges. School & College, a special report by The Chronicle, looks at efforts to fix the system. What reforms would better prepare students for college? What should schools and colleges be doing differently? How should state and federal officials help? 相似文献
14.
罗艳萍 《读与写:教育教学刊》2008,5(6)
The communication of people partially is the communication of cultures. Culture has a direct effect on international commercial activities in all aspects. Different conceptions about time, space, equality, law and the like, lead people to deal with things in different ways. So to know cultures of the counterpart is to facil-itate our enterprises so as to have a smooth and successful communication in commercial activity. 相似文献
15.
《海外英语》2007,(4):36
There are numbers of crossroads on our long and unpredictable life journey where we totally have no idea about which direction to choose. No matter what our decision is, we should not turn back, but face the music and go ahead instead. I am this kind of girl who always does try without regretting, one example is how I dealt with my love. 相似文献
16.
Migration occurs behind a variety of reasons and has a great effect on the whole world. People may migrate in order to improve their economic situation, or in order to escape civil strife, persecution, and environmental disasters. The impact of migration is complex, bringing both benefits anddisadvantages. This paper briefly talks about the causes of migration, the allocation of benefits, and the ways in which individual countries and the international community deal with this important subject. 相似文献
17.
Richard Denner 《海外英语》2007,(4):14-15
Rosco and I wait for the fishermen to return.I sit at a wooden bench near the store at Mt.Baker Resort and watch the clouds change shape. Rosco has my belt around his neck and an eight foot tow chain hooked to a tree. Dogs must be on a leash. Ducks and rabbits are loose. 相似文献
18.
Given a graph G,a subgraph C is called a clique of G if C is a complete subgraph of G maximal under inclusion and |C|≥2. A clique-transversal set S of G is a set of vertices of G such that S meets all cliques of G. The clique-transversal number, denoted as TC (G), is the minimum cardinality of a clique-transversal set in G. The clique-graph of G, denoted as K (G), is the graph obtained by taking the cliques of G as vertices, and two vertices are adjacent if and only if the corresponding cliques in G have nonempty intersection. Let F be a class of graphs G such that F={G|K(G) is a tree}. In this paper the graphs in F having independent clique-transversal sets are shown and thus TC (G)/|G|≤1/2 for all G ∈ F. 相似文献
19.
Sister Carrie is one of the most controversial characters in American literature.Thought as a "fallen woman" firstly,she was defined as a "new woman" by some critics later. However, by digging into the motivaton behind the whole process of Carrie's "success", the relationship between Carrie and her creator (the author), the social conditions of then American, it can be found that Carrie has never been free-standing on her thought and she has never found her real-sdf even after becoming a famous actress. In a society dominated by mass consumerism Carrie is only an adherent of her own desires. She also is a representative of all those country girls flooded into cities, a symbol and a sacrifice of the urbanization of America in a time countryside was overcome by cities. 相似文献