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1.
蒙自石榴丰产栽培技术研究   总被引：4，自引：2，他引：2  
蒙自石榴 ( Punica granatum)早实丰产 ,是山区群众脱贫致富的最佳经济林树种之一。本研究通过对蒙自石榴的丰产栽培技术措施进行田间试验 ,寻找较佳的技术组合 ,为滇东南岩溶山区的经济发展提供技术支撑。1　试验地概况及方法1 .1　试验地概况试验地位于北纬 2 3°39′2 3″～ 2 3°40′5 2″,东经 1 0 4°1 6′5″～ 1 0 4°1 7′39″的滇东南文山州砚山县铳卡农场 ,海拔1 60 0 m,属中亚热带半湿润型气候 ,年平均温度 1 6.1℃。年降雨量 996.4mm,日照时数 1 933.5 h,≥ 1 0℃积温4877.8℃。土壤为石灰岩上发育的山地红壤 ,土层深厚 ,但土…  相似文献   

2.
广东象头山国家自然保护区的物种多样性及其保护   总被引：4，自引：1，他引：4  
广东省惠州市博罗县中部横亘着两大山系 :东为象头山系 ,西为罗浮山系 ,广东象头山国家级自然保护区 (以下简称保护区 )位于象头山 ,距惠州市 1 8km ,地理坐标为东经 1 1 4°1 9′2 1″～ 1 1 4°2 7′0 6″,北纬2 3°1 3′0 5″～ 2 3°1 9′43″。境内海拔高度 30～ 1 0 2 4m ,森林覆盖率达 88 4%。保护区内高于 0℃的积温为 61 36 0℃ ,高于 5℃的积温为 5 85 2 7℃ ;日平均气温通过 5℃的植物生长期长达 345～ 365d ;年降水量 2 31 8 5mm ,各月均有降水 ,以 4— 9月降水量最多。雨热同季 ,对植物生长极为有利。这里地层古老 ,山势陡峭 …  相似文献   

3.
南瓮河湿地自然保护区位于大兴安岭林业东部林区的东南部 ,大兴安岭支脉伊勒呼里山南麓 ,松岭林业局境内 ,北以伊勒呼里山脉为界 ,东至二根河 ,南以松岭林业局同加格达奇林业局界为界。地理坐标为 5 1°0 5′0 7″～ 5 1°3 9′2 4″N ,1 2 5°0 7′5 5″～ 1 2 5°5 0′0 5″E ,总面积为 2 2 95 2 3hm2 :其中森林面积 1 4775 1hm2 ,疏林面积 2 2 8hm2 ,荒山荒地 3 43hm2 。湿地总面积 80 91 6hm2 ,其中水域面积 1 3 0 7hm2 ,沼泽地 7960 9hm2 。1　保护区内的生态旅游资源保护区自上古生代海西运动以来 ,经过长期的地理变迁 ,遭受了各种内…  相似文献   

4.
安阳市位于河南省北部 ,东接山东省 ,西依太行山与山西省相望 ,北隔漳河与河北省相接。区内林州市和安阳县西部为太行山区 ,全市介于东经 1 1 3°2 7′0 0″～ 1 1 4°5 8′30〃 ,北纬 35°1 3′0 0″～ 38°4 0′2 0″之间。年平均气温 1 3℃ ,日照时数为 2 5 2 6h ,全年大于 1 0℃的积温为 4 5 36℃ ,无霜期为 2 0 0d左右。年平均降水量只有 6 0 6mm ,且分布不均 ,主要集中在 7、8、9三个月。主要自然灾害为旱灾。西部太行山区成土母岩为石灰岩 ,土薄石厚 ,干旱贫瘠 ,植被稀少。 1 994年以前主要在春季栽植侧柏裸根苗 ,造林成活率不高 ,平…  相似文献   

5.
黄龙山林业局 ,地处陕北黄土高原东南部的黄龙山腹地 ,位于东经 1 0 9°38′49″～ 1 1 0°1 2′47″,北纬 35°2 8′46″～ 36°0 2′0 1″之间 ,辖区总面积 1 941 74hm2 ,其中森林面积1 44 1 2 9hm2 ,活立木蓄积 6 0 2万 m3,有林地覆盖率 74.2 % ,是全国典型的天然次生林区 ,建局近 40年来 ,黄龙山林业事业全面发展 ,特别是人工造林、封山育林工作成绩巨大。人工林的森林地位和作用在黄龙林区越来越显著 ,已经成为黄龙林区森林资源的重要类型。目前 ,在实施天然林保护 ,重视环境建设的大好形势下 ,如何经营管理好现有油松人工林 ,对恢复扩…  相似文献   

6.
1　林区概况哈思山林区位于东经 10 4°18′4 0″～ 10 4°35′ ,北纬 36°5 8′2 0″～ 37°0 2′4 0″ ,地处靖远县北部偏西石门乡的哈思山、永新乡的雪山、双龙乡的太和山等地。总经营面积为 84 0 2 .7hm2 ,包括林业用地 6 5 0 2 .2hm2 ,有林地面积 2 4 75 .0hm2 ,其中天然林135 3.8hm2 、人工林 112 1.2hm2 、灌木林 2 5 31.6hm2 ,未成林地 2 91.9hm2 ,宜林荒山荒地 1193.7hm2 。这是我省中部干旱地区罕有的天然油松纯林 ,被誉为“沙漠里的绿洲”。林区属基岩中低山地 ,是北部祁连山系褶皱断陷隆起形成的 ,山体由变质岩、花岗岩、闪长石…  相似文献   

7.
山东荣成大天鹅自然保护区水禽调查   总被引：1，自引：0，他引：1  
荣成大天鹅自然保护区是世界上最大的大天鹅越冬栖息地之一 ,每年都有万余只大天鹅来此越冬 ,还有数十万计的雁鸭、海鸥等鸟类。它们或成群结队 ,翱翔蓝天 ,或栖息水面 ,形成许多壮丽的景观。为了更好地保护和利用这一宝贵资源 ,我们利用 5年的时间 ,对保护区的水禽种类进行了调查和研究。现将结果报告如下。1　保护区概况荣成大天鹅自然保护区 ,地处山东半岛的最东端 ,介于东经 12 2°17′44″～ 12 2°42′16″ ,北纬 36°5 3′3″～ 37°2 6′7″之间 ,南、北、东三面濒临黄海 ,由众多港湾和浅海滩涂组成 ,总面积 10 5 0 0ｈｍ2 。这里属…  相似文献   

8.
日本落叶松引种育苗试验初报   总被引：1，自引：0，他引：1  
日本落叶松 ( Larix kaempferi)原产地日本 ,落叶乔木 ,高达 35m,胸径 1 m,适应范围广 ,前期生长较快 ,抗病性较强 ,在我国引种栽培已有 88年历史。日本落叶松的天然分布区为北纬 35°2 0′～ 38°1 0′。东经约为1 36°4 5′～ 1 40°30′的范围内 ,垂直分布于海拔高 90 0～ 31 0 0 m之间。日本落叶松是喜光树种 ,根系较浅 ,对气候的适应性较强 ,在年平均气候 2 .5～ 1 2℃ ,年降水量 50 0～1 40 0 mm的气候下都能生长。日本落叶松较华北落叶松有萌动迟、封顶及落叶晚、生长期的顶端优势强等特性 ,是良好的建筑材料。根据日本落叶松的生物…  相似文献   

9.
管涔林区属于省直国有林区 ,地处吕梁山脉北端、黄河中游地段 ,是汾河的发源地。其生态效益在全省生态环境总体框架中 ,占据着十分重要的地位。近两年来 ,林区天然林资源保护工程取得了明显成效 ,实现了林业经营方式、经营目标的历史性转变。1　管涔林区自然状况1.1　自然环境管涔林区地处东经 111°38′5 4″～ 112°33′0 4″、北纬38°2 4′34″～ 39°0 3′0 6″之间 ,其经营范围纵跨忻州市的宁武、神池、五寨、岢岚、静乐、原平 6县 (市 ) ,南北长70 .3km,东西宽 78.75 km。管涔山主峰为荷叶坪 ,海拔2 787m,最低海拔 12 89m,相对高差 1…  相似文献   

10.
渝东南地区的黔江区属山区 ,位于北纬 2 9°0 4′2 7″～ 2 9°5 2′10″,东经 10 8°2 8′0 4″～ 10 8°5 6′5 6″,年均温度 15 4℃ ,年均降水1194ｍｍ ,最低海拔 32 0ｍ ,最高海拔 1938.5ｍ。当地乡土造林树种主要是马尾松、杉木、柏木。为了给退耕还林工程、天然林资源保护工程、速生丰产用材林工程等提供更多的树种选择 ,本区于 1999年 10月开始中潜 3号杨树引种育苗试验 ,效果较好 ,1年生苗平均高 2 .9ｍ ,平均地径 1.8ｃｍ。笔者将在中低山丘陵地区培育中潜 3号杨树壮苗技术介绍如后。1　圃地选择通过育苗试验 ,中潜 3号杨树在光照…  相似文献   

11.

In Scandinavia, moose (Alces alces L.) sometimes cause severe browsing damage to economically-important pine. Moose-vehicle accidents have spurred construction of fences along roads, and these may interfere with moose migration between summer and winter ranges, or the road alone may be a barrier. If this happens and moose build up along roads, landowners may suffer economically. Therefore, this study investigated whether roads, fences or other factors influence the use of young pine stands by moose. Eighty stands along roads in northern Sweden were evaluated in which individually-browsed branches were counted on 9972 pines. Moose browsing was not significantly related to birch (Betula pendula Roth, B. pubescens Ehrh.) density, nor did it differ between pines (Pinus contorta Douglas or P. sylvestris L.). However, increased pine density, site productivity and proximity to a highway were associated with increased browsing. Further large-scale studies are needed to understand moose habitat selection and the effects of roads.  相似文献   

12.

The root systems of 2-yr-old Picea glauca, Picea mariana and Pinus banksiana seedlings were submitted to various frost temperatures during an artificial frost to induce different levels of root damage. Frost-damaged and control seedlings were placed in a greenhouse under high and low soil moisture regimes. Seedling growth and physiology were evaluated periodically. Seedling survival was reduced when root damage reached levels of 60-80%. Root systems of all three species showed partial to total recovery by the end of the experiment. In general, root freezing damage caused reductions in seedling growth, with these reductions becoming less significant over time. Root damage had little to no effect on black spruce and jack pine seedling physiology, while white spruce CO 2 uptake decreased with increasing root damage. Shoot nitrogen content of all three species decreased slightly with increasing root damage.  相似文献   

13.

This study investigated the stand structure in pine, spruce and deciduous forests in the border district of Finland and Russia. A total of 46 mature forest stands was selected as pairs, the members of each pair being as similar as possible with respect to their forest site type, age, moisture and topography. The stands were then compared between the two countries by means of basal areas and number of stems. The proportions of dominating tree species were 2-12% lower, and correspondingly the proportions of secondary tree species higher, in Russian forests. The density of the forest stock was also higher in each forest type in Russia. The forests in the two countries differed most radically in terms of the abundance of dead trees. The amount was two to four times higher in Russian deciduous and spruce forests, and in pine forests the difference was 10-fold. The stand structures indicated that Russian coniferous stands, in particular, were more heterogeneous than intensively managed pine and spruce stands in Finland.  相似文献   

14.

The root collar diameter and the height:diameter ratio are of particular importance in container-grown seedlings where a high density in the containers may produce spindly seedlings. Temperature regimes and light quality are known to affect plant growth. The aim of this study was to identify responses in Picea abies (L.) Karst. seedlings grown with light providing different red:far-red ratios and under temperature regimes with alternating day (DT) and night temperature (NT) from negative (DT < NT) to positive (DT > NT) difference (DIF) between DT and NT. Experiments were conducted in controlled environment chambers and in a daylight phytotron. Only limited thermoperiodic responses appeared in P . abies seedlings with respect to seedling height and dry weight accumulation. The formation of terminal buds, however, was clearly delayed in seedlings grown at negative DIF. The results indicate a requirement for day extension light that is high in far-red, to prevent terminal bud formation under natural short-day conditions. An extended study should be conducted to clarify the minimum level of light intensity and the optimal light quality needed to prevent terminal bud formation under natural short-day conditions.  相似文献   

15.
本文分析了CAD在设计中引起的正面和负面影响,并进行了系统的阐述,从而使设计者在应用中能够保持客观的态度。  相似文献   

16.
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17.

Based on an enquiry, risk perception among non-industrial private forest owners is described in relation to climate change and forestry hazards. Of the respondents, 11% took action to remedy the effects of climate change. Out of a given set, hazards were ranked according to each respondent's experience of recent substantial financial loss to the estate and in relation to his or her willingness to make investments aimed at risk reduction. For each hazard, the respondent assessed the risk in four classes ranging from very high to negligible risk. Six hazards were considered most problematic in all three aspects: browsing damage, falling timber prices, damage by wind, spruce bark beetle, root rot and pine weevil. A majority of the respondents claimed to take action to reduce the risk associated with at least one hazard, while 35% did not know whether they did. Excluding climate change, the need for decision support was the largest in relation to damage by wind owing to a combination of perceived high risk and a high level of ignorance in relation to whether risk-reducing measures were taken.  相似文献   

18.
In situ produced plant residues contain a mixture of different plant components of varying quality. To assess synergistic or antagonistic interactions occurring during the decomposition and mineralization of such mixtures, individual plant parts (stems, leaves, leaf litter and roots) or the mixture of stems, leaves and leaf litter of the agroforestry species pigeonpea (Cajanus cajan) or of crop residues of peanut (Arachis hypogaea) or of the weed hairy indigo (Indigofera hirsuta) were incubated in pots for 19 weeks. Periodically, remaining plant residues were sieved out (>2 mm), weighed and N content as well as soil mineral N determined. Above- and below-ground residues of peanut decomposed fastest and showed the largest N release in agreement with their high N concentration and low-acid detergent fibre (ADF) : N ratio. Hairy indigo was hypothesized to be of lower quality than pigeonpea because of its high-polyphenol content. However, it decomposed faster than pigeonpea, largely because of the higher N and lower lignin concentration of its components. Ranking of individual plant components for N mineralization resulted in the following pattern, leaves > leaf litter > roots > stems. In mixtures of the different plant components a similar species order in decomposition was obtained, e.g. peanut > hairy indigo > pigeonpea. The amount of N released from the mixture was dominated by stem material that comprised 46–61% of the mixture. The interactions in mixtures were relatively small for peanut (generally high-quality components) as well as for pigeonpea (low proportion of high-quality components, i.e. N rich leaf material). However, a positive interaction occurred during later stages of N mineralization in the mixture of hairy indigo as it had a significant proportion of N rich components and absence of highly reactive polyphenols. Thus, for plants with low to intermediate chemical quality attributes, manipulating plant composition (e.g. by varying harvest age, affecting stem and leaf proportions) will be important to obtain significant interactions during decomposition when its components are mixed.  相似文献   

19.
The use of organic waste materials such as milk sewage as an organic fertilizer could have the dual advantages of organic-waste disposal and reduced dependence on inorganic fertilizers. The effects of fertilization with (1) conventional mineral fertilization, (2) milk sewage sludge at 40 kg N ha−1 target rate and (3) no fertilization on pasture production and tree growth were examined in an experiment consisting of two pasture mixtures under a one-year-old Pinus radiata plantation with a density of 2500 trees ha−1. The two pasture mixtures were: (1) Dactylis glomerata L. var. saborto (25 kg ha−1) + Trifolium repens L. group Ladino (4 kg ha−1) + Trifolium pratense L. var. Marino (1 kg ha−1); (2) Lolium perenne L. var. Tove (25 kg ha−1) + Trifolium repens L. group Ladino (4 kg ha−1) + Trifolium pratense L. var. Marino (1 kg ha−1). The experiment began in the spring of 1995 using a randomized block design with three replicates in Castro Riberas de Lea (Lugo, Galicia, north-western Spain). Plot size was 12 × 8 m2, with a 1 m buffer strip between plots. Two-year data showed that fertilization with either material had a positive effect on pasture production, with no significant difference between the two fertilization treatments. Tree growth in the milk sewage sludge plot was significantly higher than in the control plots. Inorganic fertilization increased pasture production, but affected tree growth negatively. The results show that milk sewage sludge could be used as a fertilizer in silvo-pastoral systems. This revised version was published online in June 2006 with corrections to the Cover Date.  相似文献   

20.

This study investigated the forest history, structural characteristics, the presence of fungal species suggested to indicate ecological continuity in old-growth forest, and the species composition of saproxylic beetles in 30 old forest ''woodland key habitats'' (WKHs), and compared them with production forest in the same age-class in south-eastern Norway. No statistically significant differences in forest characteristics, community of saproxylic beetles or number of red-listed beetles were found between the WKHs and the production forest, probably owing to a combination of profound long-term logging and a lack of will to delineate sufficiently large WKHs in the one area with significantly less forestry impact. The study indicates the advantage of including forest history information in WKH selection where such data exist, and the importance of restoring habitats in heavily exploited forest landscapes.  相似文献   

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