首页 | 本学科首页   官方微博 | 高级检索  
相似文献
 共查询到20条相似文献,搜索用时 187 毫秒
1.
对罗布麻白麻在青海高原的柴达木盆地野生分布群落进行了调查、分析与研究,初步掌握其分布的生境、分布状况、生长状况及种群的繁衍,可以为野生罗布白麻资源的合理有效利用及恢复提供理论依据。  相似文献   

2.
由于植物的生物量是其获取外界资源的基础,生物量分配是植物对资源利用最大化的一种生长策略,探讨了不同环境下的生长策略有助于预测未来环境变化下植物的生长和分布趋势.分别从自然环境和人为干扰两种因素下综述了植物在不同生态条件下生物量的分配格局,总结了在不同生长条件下植物各构件生物量分配差异,阐述了植物通过改变地上与地下部分,...  相似文献   

3.
积极开发利用甘草资源郭玉洪地处东北、华北、西北三角地带的敖汉旗具有独特的自然地理条件,形成了低山丘陵、黄土丘陵、沿河不川、浅沙坨汇集的自然景观。适合甘草生长的栗钙土占据全旗土壤大部,大自然赐予敖汉大地丰富的甘草资源。全旗甘草分布面积270万亩,甘草总...  相似文献   

4.
四川省麻疯树天然林资源的调查与分析   总被引:3,自引:2,他引:1  
利用近期卫星遥感图片解译结果并结合实地调查,对四川麻疯树天然资源分布情况及生长特点进行了初步调查。结果表明:(1)四川麻疯树天然林资源总面积为34194hm2,主要沿金沙江、安宁河和雅砻江干流及其支流干热河谷呈窄带状水平分布;垂直分布范围为海拔400m—1800m。主要分布范围为海拔800m—1400m,其占四川天然林麻疯树总面积的84.47%。(2)分布方式以零星分布为主,夹杂有团条状分布、成片少,成片分布面积仅占总面积的22.25%。(3)通过对麻疯树天然林资源权属、地类、起源、面积、立地因子、株数、密度、树高、冠幅、生长状况、结实状况、生境状况、病虫害等情况的调查表明,四川麻疯树天然林资源具有雌雄花比例失调、单株产量差异大、病虫害严重、徒长枝多等一系列特点。(4)在宏观上,麻疯树在四川的适生区域为雅砻江流域的中下游及其支流安宁河流域的中下游及金沙江攀枝花、会理、会东段的部分支流的河谷地带。  相似文献   

5.
根据新疆维吾尔自治区的气象资料及已知的胡杨、铃铛刺、黑果枸杞、甘草的物种分布情况,采用Arcgis与MaxEnt模型相结合的方式,对胡杨等4种植物在新疆生长的适生区进行预测。结果表明:胡杨、铃铛刺、黑果枸杞、甘草的适生区面积分别占新疆总面积的40.79%,38.54%,41.99%,30.55%。对胡杨分布预测贡献率最高的两个气象因子分别是平均相对湿度与平均昼夜温差;对铃铛刺与黑果枸杞分布预测贡献率最高的两个气象因子分别是等温性与最冷月最低温;对甘草分布预测贡献率最高的两个气象因子分别是等温性与年均昼夜温差。经ROC曲线验证,显示该预测结果准确。结合刀切法对各因子贡献率的分析结果,总结出4种植物共同适生的气象条件为:平均湿度60%以上,年均昼夜温差25.5℃以下或27.25~27.5℃,等温性介于36~36.5之间,最冷月最低温大于-20℃。  相似文献   

6.
介绍了广东陆河南万红锥林省级自然保护区拥有珍稀濒危保护植物11科32种,主要观赏资源植物15科131种,主要药用植物44科82种。经简要分析认为,这些植物具有很重要的保护利用价值,但是,迄今对珍稀濒危资源植物的保护利用仍缺分布矢量位置档案、人工繁殖技术等短板,对具有地方特色的观赏资源植物尚未开发利用,对药用资源植物的保护利用不到位且不科学等问题。为此,提出了加强资源植物的调查监测,尤其加强对珍稀濒危物种的保育和观赏、药用等资源植物的保护利用,是打通“绿水青山”与“金山银山”转化通道的重要基础性工作;同时,也提出了进一步完善资源植物分布特点、频率、频度和矢量位置等方法,可供相关研究参考。  相似文献   

7.
麻疯树是广泛分布于我国热带、亚热带地区的一种多功能综合性树种。本文概述了麻疯树资源的用途和地理分布,以及我国麻疯树资源的分布特点和不同地区的分布差异,为麻疯树种质资源的调查、收集和评价工作提供参考。  相似文献   

8.
广西栲属植物及其开发利用研究   总被引:1,自引:0,他引:1  
研究广西栲属(Castanopsis)植物资源的分布、种类及该属植物在生态、木材及工业原料、营养、药用等多方面的利用价值.结果表明,栲属植物为广西地带性植被顶级群落主要优势种,具有易更新、生长快、经济价值高等特点.  相似文献   

9.
以北京小西山资源植物为研究对象,对该区资源植物种类及分布状况进行调查,分析植物区系组成,将该区资源植物划分为食用类植物、药用植物、保护和改造环境植物、野生观赏植物、森林文化植物5种类型,对各类型资源植物的具体组成特征进行分析,指出资源植物利用现状问题:对资源植物的潜在价值认识不深,对特色资源植物生境的保护意识不够,利用形式单一,缺乏系统利用,人为干扰严重。提出建立资源植物数据库,实行资源植物动态监测机制,确立资源植物保护以生境保护为先的整体保护理念,与森林多功能利用相结合,统筹发展资源植物,与森林文化建设相结合,突出地方资源植物特色等资源植物保护与利用建议。  相似文献   

10.
小五台山桦木科植物调查研究   总被引:1,自引:0,他引:1  
该次研究通过实地踏查的方法,对小五台山的桦木科植物资源进行了详细的调查.并对桦木科植物资源的种类及其生长分布的调查结果进行了系统的分析,找出了桦木科植物的分布特点,对保护和利用桦木科植物资源提供了依据.针对桦木科植物资源种类数量减少的原因,提出对应的解决方案,对小五台山桦木科植物资源的保护具有重要意义  相似文献   

11.
We surveyed the germination number (N cs) of 2-year and a 1-year survival of Abies sachalinensis and Picea jezoensis seedlings and saplings on 29 fallen logs from 2004 to 2005 in a natural coniferous forest in Hokkaido, northern Japan, in relation to the surface and light conditions of fallen logs. Moss height (H moss), log hardness (Hardness), and the area of fallen log (Area) were measured as the surface conditions by each 1-m block from bottom to top of all fallen logs. The relative photosynthetic photon flux density (rPPFD) 10 cm above the tallest seedling in each block was measured as the light condition. In addition, the height of the tallest seedling or sapling in each block (H max), the difference between a height of each seedling and sapling and the H max (Shading), and a height of seedlings and saplings in 2004 (H ini) were considered. N cs of A. sachalinensis was affected by Hardness and Area, whereas N cs of P. jezoensis was affected by H moss, Hardness, Area, H max, and rPPFD. The survival of seedlings (height < 5 cm) and saplings (5 cm ≤ height < 50 cm) were affected by H ini, rPPFD, and shading for both species. However, the survival of P. jezoensis saplings was more sensitive to decrease in rPPFD and increase of shading than that of A. sachalinensis. Therefore, seedling emergence was influenced by surface conditions, whereas survival was affected by light conditions. Furthermore, P. jezoensis emergence and survival were more sensitive to surface and light conditions than that of A. sachalinensis.  相似文献   

12.
To promote afforestation in sandy lands and increase the effects of prevention and control of desertification, the application of a new drought-resistant product—solid water and foliar fertilizer “Shifengle”—was studied. A comparison of three treatments (solid water, foliar fertilizer, and control) showed that both solid water and foliar fertilizer increased plant survival rate by 10% and 18.2%, respectively. Afforestation survival rates of Salix psammophila and Hedysarum mongolicum reached over 90%. In addition, height and crown growth as well as biomass of seedlings were improved by the treatments. __________ Translated from Journal of Beijing Forestry University, 2006, 28(3): 76–80 [译自: 北京林业大学学报]  相似文献   

13.
Allelopathic effects of eucalyptus are widely reported and are considered the major factor limiting the establishment of native species in eucalyptus forests. However, reports of the allelopathic effects of eucalyptus are mostly based on laboratory bioassay, not on field trials. In the present study, we conducted field trials to determine the allelopathic effects of eucalyptus and to develop strategies for establishment of mixed stands of native species and eucalyptus. In the field, seed germination and seedling survivorship of native species were determined in the presence and absence of eucalyptus leaf litter or living roots. In the seed germination experiment, seed germination rate of Delonix regia was higher than for Elaeocarpus sylvestris and Tsoongiodendron odorum. Seed germination rates of E. sylvestris and T. odorum were low in both the presence and absence of eucalyptus treatments. The germination rate of D. regia was significantly inhibited by all eucalyptus treatments, but only during the early period. In the seedling establishment experiment, seedling survivorship of E. sylvestris and Michelia macclurel was not inhibited by any treatments, but the seedling survivorship of Schima superba was significantly inhibited by eucalyptus litter addition alone. Seedling height of S. superba and M. macclurel was significantly suppressed when eucalyptus roots were present in treatments, but the seedling height of E. sylvestris was only significantly suppressed by the treatment of roots alone. We propose two strategies for establishment of mixed stands of native species and eucalyptus: (1) direct seed-sowing is effective only for those species (e.g. D. regia) with high germination rates in natural conditions; (2) seedling transplants are more efficient approach for establishing species (e.g. E. sylvestris) with low germination rates. We suggest that mixed plantations of eucalyptus and E. sylvestris can be established by transplanting seedlings of E. sylvestris into eucalyptus plantations.  相似文献   

14.
We exposed the roots of nine Myrtaceae species (Melaleuca bracteata F. Muell., Melaleuca cajuputi Powell, Melaleuca glomerata F. Muell., Melaleuca leucadendra [L.] L., Melaleuca quinquenervia [Cav.] S.T. Blake, Melaleuca viridiflora Sol. ex Gaertner, Eucalyptus camaldulensis Dehnh., Eucalyptus deglupta Bl., and Eucalyptus grandis W. Hill ex Maiden) to 1 mM Al in a nutrient solution for either 24 h or 20 days to evaluate their sensitivity to excess Al and to determine whether callose and lignin formation can be used as interspecific indicators of Al sensitivity. Inhibition of root elongation by Al varied among the species. Melaleuca leucadendra, M. cajuputi, E. grandis, M. quinquenervia, and E. deglupta were tolerant to 1 mM Al, whereas M. viridiflora, E. camaldulensis, M. glomerata, and M. bracteata were sensitive to 1 mM Al. We found that Al induced callose formation in the root tips of each species, but lignin was formed only in the root tips of the most sensitive species, M. bracteata. Root elongation at 1 mM Al was negatively correlated with Al-induced callose formation but not with the Al-induced lignin formation in the root tips. These results suggest that Al-induced callose formation, rather than lignin formation, can be used as an interspecific indicator of Al sensitivity.  相似文献   

15.
Phytophthora pluvialis and Phytophthora kernoviae are the causal agents of important needle diseases on Pinus radiata in New Zealand. Little is known about the epidemiology of the diseases, making the development of control strategies challenging. To investigate the seasonality and climatic drivers of sporulation, inoculum traps, consisting of pine fascicles floating on water in plastic containers, were exchanged fortnightly at five sites in P. radiata plantations between February 2012 and December 2014. Sections of needle baits were plated onto selective media and growth of Phytophthora pluvialis and P. kernoviae recorded. To explore the generalizability of these data, they were compared to detection data for both pathogens from the New Zealand Forest Health Database (NZFHDB). Further, equivalent analyses on infection of Rhododendron ponticum by P. kernoviae in Cornwall, UK allowed the comparison of the epidemiology of P. kernoviae across different host systems and environments. In New Zealand, inoculum of P. pluvialis and P. kernoviae was detected between January–December and March–November, respectively. Inoculum of both species peaked in abundance in late winter. The probability of detecting P. pluvialis and P. kernoviae was greater at lower temperatures, while the probability of detecting P. pluvialis also increased during periods of wet weather. Similar patterns were observed in NZFHDB data. However, the seasonal pattern of infection by P. kernoviae in the UK was the opposite of that seen for sporulation in New Zealand. Phytophthora kernoviae was likely limited by warmer and drier summers in New Zealand, but by colder winter weather in the UK. These results emphasize the importance of considering both environmental drivers and thresholds in improving our understanding of pathogen epidemiology.  相似文献   

16.
The shamba system involves farmers tending tree saplings on state-owned forest land in return for being permitted to intercrop perennial food crops until canopy closure. At one time the system was used throughout all state-owned forest lands in Kenya, accounting for a large proportion of some 160,000 ha. The system should theoretically be mutually beneficial to both local people and the government. However the system has had a chequered past in Kenya due to widespread malpractice and associated environmental degradation. It was last banned in 2003 but in early 2008 field trials were initiated for its reintroduction. This study aimed to: assess the benefits and limitations of the shamba system in Kenya; assess the main influences on the extent to which the limitations and benefits are realised and; consider the management and policy requirements for the system’s successful and sustainable operation. Information was obtained from 133 questionnaires using mainly open ended questions and six participatory workshops carried out in forest-adjacent communities on the western slopes of Mount Kenya in Nyeri district. In addition interviews were conducted with key informants from communities and organisations. There was strong desire amongst local people for the system’s reintroduction given that it had provided significant food, income and employment. Local perceptions of the failings of the system included firstly mismanagement by government or forest authorities and secondly abuse of the system by shamba farmers and outsiders. Improvements local people considered necessary for the shamba system to work included more accountability and transparency in administration and better rules with respect to plot allocation and stewardship. Ninety-seven percent of respondents said they would like to be more involved in management of the forest and 80% that they were willing to pay for the use of a plot. The study concludes that the structural framework laid down by the 2005 Forests Act, which includes provision for the reimplementation of the shamba system under the new plantation establishment and livelihood improvement scheme (PELIS) [It should be noted that whilst the shamba system was re-branded in 2008 under the acronym PELIS, for the sake of simplicity the authors continue to refer to the ‘shamba system’ and ‘shamba farmers’ throughout this paper.], is weakened because insufficient power is likely to be devolved to local people, casting them merely as ‘forest users’ and the shamba system as a ‘forest user right’. In so doing the system’s potential to both facilitate and embody the participation of local people in forest management is limited and the long-term sustainability of the new system is questionable. Suggested instruments to address this include some degree of sharing of profits from forest timber, performance related guarantees for farmers to gain a new plot and use of joint committees consisting of local people and the forest authorities for long term management of forests.
Peter DorwardEmail:
  相似文献   

17.
Swamy  S.L.  Puri  S.  Singh  A.K. 《New Forests》2002,23(2):143-157
Juvenile (2 year old trees) and mature hardwood (15 year old trees) cuttings of Robinia pseudoacacia and Grewia optiva were tested for their capacity to form roots. Cuttings were prepared in spring, monsoon and winter seasons and treated with different concentrations (250, 500 and 750 mg/l) of IBA and NAA. These were planted in a mist chamber maintained at 25±1°C with relative humidity >70%. Juvenile cuttings of both species rooted significantly better than mature hardwood cuttings in all three seasons, and the age effect was more pronounced in auxin treated cuttings. The highest rooting in juvenile (83.3%) and mature (66.6%) cuttings was observed with the NAA (500 mg/l) treatment in R. pseudoacacia during the spring season. In G. optiva, IBA (250 mg/l) in the monsoon season was most effective and yielding a maximum of 80% and 70% rooting in juvenile and mature cuttings, respectively. Auxin treatments also significantly enhanced the number of roots, root length, leaf number and leaf area. Statistical analysis of data revealed that interactions between age, season and treatments were significant at P <0.05 level for R. pseudoacacia and non-significant for G. optiva.  相似文献   

18.
From January 2001 to December 2004, the investigation on the species of insect pests and diseases in Torreya grandis Merrillii was conducted and integrated control technologies of the main insect pests and diseases were studied in Zhuji, Shaoxin, Shenzhou, Dongyang, and Jiande counties of Zhejiang Province. Via field survey, a system of regular observations, 55 species of insect pests belonging to 9 orders and 29 families, and 4 species of diseases were recorded. Among them, Lepteucosma torreyae and Macrolygus torreyae were found to be new species. The biological characteristics of the major insect pests and diseases, such as Rhyncaphytoptus abiesis, Helicobasidium compacum, Erwinia carotovora, Chlorella sp., Macrolygus torreyae, and Lepteucosma torreyae, were primarily recorded, and their outbreaks and epidemics were researched. The forecasting method for Lepteucosma torreyae was established. Based on strengthening cultivation and management, integrated control measures were put forward including physical, biologic and chemical methods. Medications with higher effect and lower toxicity were screened by comparing the effect of different pesticide treatments. __________ Translated from Journal of Zhejiang Forestry College, 2005, 22(5): 545–552 [译自: 浙江林学院学报, 2005, 22(5): 545–552]  相似文献   

19.
Three multipurpose tree species (MPTS)-leucaena (Leucaena leucocephala), sesbania (Sesbania sesban var. nubica) and pigeonpea (Cajanus cajan) were pruned at a height of 60 cm above the ground every two months, and resulting plant biomass was incorporated into the soil as green manure. For comparison, maize (Zea mays) stover was also incorporated into some plots, while some other plots were left fallow. Varying quantities of plant biomass which were incorporated into the soil over a period of 12 months caused large changes in major soil plant nutrients, and it substantially improved soil fertility. To test for improved soil fertility, test crops of maize and beans (Phaseolus vulgaris) were grown on the plots after six biomass incorporations of 4806, 13603, 16659 and 7793 kg. ha–1yr–1 for pigeonpea, sesbania leucaena and maize, respectively. Responses of the test crops indicated that sesbania and leucaena green manures improved maize stover, cobs and grain yields; and bean haulms and grain yields by 77.6% when compared to fallow plots. Residual effects of green manures still resulted in significant (P < 0.05) yield differences in the test cropin the third testing season. Economic significance of green manures in increasing food crop yields to small scale farmers is discussed.  相似文献   

20.
班克木种子形态及发芽特征在种内与种间的变异   总被引:2,自引:2,他引:0       下载免费PDF全文
对引自澳大利亚的班克木属5个种18个种源进行种子形态、质量以及发芽特征测定,结果表明:班克木属种子形态、质量和发芽特征在种间和种内均有不同的差异表现;香花班克木种子千粒质量最大,约106.5 g,为其他种的4~9倍;种子千粒质量与发芽率无显著相关;除红花班克木在试验期间未发芽外,其余4个种的发芽率皆高于60%,强力班克木发芽率最高,约80%;长圆叶班克木和强力班克木种子发芽速度最快,而香花班克木发芽速度最慢;发芽始期、发芽速度、发芽率、胚轴长、胚根长都和经度呈极显著正相关(P<0.01),即自西澳的珀斯至东澳的塔斯马尼亚地区,种子的发芽始期越晚,发芽速度慢,发芽率越高,胚轴和胚根的生长量越大.对于5种班克木的发芽特征的研究表明:强力班克木在广州的适应性最强,其发芽率最高,发芽速度最快,发芽最早且胚根长度最大.  相似文献   

设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号