共查询到19条相似文献,搜索用时 281 毫秒
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本文应用数量化理论Ⅰ,对燕山东段封山育林区油松天然更新与林分结构因子、立地因子之间的关系进行了系统分析,并建立了相应的预测模型。结果表明,影响油松天然更新的主要因子是林分蓄积量、坡向、坡位、灌木层盖度、林分郁闭度,其他因子的影响较小。文中还对主要影响因子的作用机理进行了探讨,为开展油松大然更新工作提供了理论依据。 相似文献
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《河北林果研究》1990,(4)
动回@@1问河北燕山东段低山丘陵绿化研究··二“C·\……··、…·二’M…··碉询宝 裴@华 冯耕田()。。…。e。。。。。。。。。。x,x。2.7ffl拙k一。_rs t 6影响燕山低山丘陵油松天然更新的主导因于分忻“·‘和“”·“·‘郭果折 李忑增 土沫队(7jJ燕山低山丘陵油松林及其经营··!·。V好弘卫凡……………………·郭庆侦 孙肇香(旧)油松封山育林的研究··上7j么巧y燃…e··~………··李志增 郭泉水 王保江*6)。。。。。。。。。。。。。①。吴k.d趴父……../。。。。、。@#门S)杆林及其经营··)刀K从以上C—………·—…·… 相似文献
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对平顺县油松天然更新的种源、种子繁殖特性、油松封山林区天然更新状况的调查和定位试验研究表明,在太行山石灰岩区开展油松封山育林,恢复和扩大油松资源的可行性。 相似文献
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油松天然更新的调查研究 总被引:1,自引:0,他引:1
油松的天然更新,是以油松林木的自身能力,借助于自然条件进行天然下种、恢复森林的。因此,油松林地的天然更新好与坏,直接影响油松林分是否长期生存、速生丰产和永续利用的大问题。为了更好地掌握和利用影响油松天然更新的因子。我们对沈阳市东南山区内的油松林地天然更新状况进行了调查研究,从中摸索油 相似文献
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笔者从幼苗的年龄结构和高度结构两方面研究了30年生油松纯林下天然更新幼苗的群落关系和分布格局,结果表明,随着群落演替,油松幼苗种群的年龄结构有明显变化,幼苗以7年生-8年生居多;幼苗主要集中在30cm以下种群高度上;幼苗随年龄和高度的增加数量逐渐减少,考虑其原因主要是人为干扰;油松天然更新幼苗的空间分布格局呈聚集分布。 相似文献
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本文通过对抚宁县、卢龙县境内的天然次生油松林的调查研究指出,由于近年来不合理的反复择伐和整枝,多数Ⅰ~Ⅱ龄级的油松林已成为径级小、干形不良和庇护土壤能力极低的稀疏林分。有纯林也有混交林,有同龄林也有异龄林。林内有油松和栎树的天然更新幼树。文中论述了用油松林疏伐保留株数标准控制油松林密度问题,并制定了合理整枝标准;特别强调对油松林应采取封山育林措施,促进油松的天然更新,变疏林为密林。 相似文献
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ZHU Jiao-jun KANG Hong-zhang TAN Hui XU Mei-ling WANG Jun 《林业研究》2005,16(4):253-259
Natural regeneration in Mongolian pine, Pinus sylvesttis var. mongolica, forest at Honghuaerji of China (the original of the natural Mongolian pine, forest on sandy land) was studied in 2004. The total mean values of regeneration indexes were higher in mature stands (more than 80% individual stems were older than 50 years), the maximum of regeneration index reached 29 seedlings, m^ 2, with lowest values in the younger stand, e.g., in 32-year old and 43-year old stands. The stand age was an important factor determining the natural regeneration, which was the best in the older stands in this investigation (e.g. about 80-year old). The regeneration index seemed not to be closely in relation to canopy openness although Mongolian pine is a photophilic tree species. In each type of gaps, natural regeneration was very well. Regeneration indexes were satisfactory at the south and east edges in the circle gaps; and at the east edge of the narrow-square gaps. Results indicated that Mongolian pine, seedlings could endure shading understory, but it would not enter the canopy layer without gap or large disturbance, e.g., fire, wind/snow damage or clear cutting etc. These results may provide potentially references to the management and afforestation of Mongolian pine, plantations on sandy land in arid and semi-arid areas. Researches such as the comprehensive comparisons on regeneration, structure and ecological conditions and so on between natural Mongolian pine, forests and plantations should be conducted in the future. 相似文献
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Broad-lcafKorcanpi11cforcstbccol11csPoplar-bircl1forcstaftcrburntandfcllcdinbigarcas.Ca11tl1iskindofPopIar-bircl1forcstrccot'crtoclin1axco1nl11unity-trirginbroadlcafKorcanpincforcst9Whatistl1erclationsl1ipbctt`.ccnPoplar-birchforcstandKorcanpil1cforcst?Ho`"docsKorcanpincPOpu1ationrc-gencratcundcrnaturaIPoplar-birchforcst?AllthescprobICInsl1a\'caIrcad}'attractcdforcstcrsattcntionforaIOI1gtil11c.Tllccarh'studicsshox'cd:itt'asinct-ita-blcthatbirchforcstcouldfonnonbun1ingsitesx"ithil1t'irg… 相似文献
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Efrat Sheffer 《Annals of Forest Science》2012,69(4):429-443
Context
Mediterranean landscapes are composed of different interacting vegetation patches. Pine and oak ecosystems form contiguous patches within these landscapes, in pure stands, or as mixed pine?Coak ecosystems. During the nineteenth century, pine forest distribution in the Mediterranean Basin increased dramatically as a result of large-scale re-forestation and spontaneous forest regeneration. At the same time, secondary succession of abandoned agricultural land allowed development of pine and oak ecosystems. Consequently, a pine?Coak mosaic has developed, which created opportunities for cross-colonization, i.e. species colonization from one ecosystem in the reciprocal system. Pines shed their wind-dispersed seeds and colonize Mediterranean oak vegetation. Oaks regenerate in different ecosystems, including pine forest understories.Research question
This paper reviews fire-free landscape-scale dynamics of pine?Coak Mediterranean mosaics and analyze how landscape-scale interactions are leading to pine?Coak ecosystems by different processes.Results
Published information from the Mediterranean Basin illustrates pathways of pine?Coak ecosystems formation. Using Mediterranean literature, I try to elucidate the factors that (1) control colonization potential and (2) modulate the resistance to colonization, in different habitats, land uses, and landscape settings.Conclusion
Management implications for these mixed pine?Coak ecosystems are suggested. The question of whether they are novel ecosystems is discussed. 相似文献15.
According to a great deal of field investigation and detailed indoor analysis, the natural regeneration pattern and process
of Korean pine population under natural Poplar-birch forest has been uncovered. The results show that the regeneration quantity
and quality of Korean pine population under mountainous Poplar-birch forest and mountainous white birch forest are better
than those under valley moss-grass White Birch forest and virgin broad-leaved Korean pine forest. Korean pine population shows
aggregated distribution, the mass-occurrence period of Korean pine population is behind the mass-occurrence period of Poplar-birch
population. Various aged Korean pines growth is affected by different stand structure factors. Man-made lighting tending can
accelerate the regeneration process and increase the regeneration quality of Korean pine population. It is feasible to set
up regeneration recombination of upper layer White Birch and lower layer Korean pines. 相似文献
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秦岭林区天然油松林结构研究初报 总被引:5,自引:1,他引:5
对秦岭林区天然油松林年龄结构,直径结构分析研究表明,天然油松林按林层和林龄可划为单层异龄林和复层异龄林两类。单层异龄林的天然更新表现出明显的连续性和阶段性,而复层异龄油松林的年龄结构出现多世代波动现,直径结构的波动随林龄的增加,其偏度具有一定的方向性。 相似文献
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湘乡市林地森林碳储量及碳密度研究 总被引:1,自引:0,他引:1
通过对湘乡市林地的森林碳储量、碳密度及碳储量的空间分布特征进行研究,得出:①在各优势树种组中,中生阔叶树组的碳储量和碳密度都是最大的,碳储量排序依次为:中生阔叶树组>马尾松组>杉木组>竹木组>国外松组>经济林组〉慢生阔叶树组>灌木组>速生阔叶树组,碳密度排序依次为:中生阔叶树组>国外松组>竹木组>马尾松组〉慢生阔叶树组>杉木组>经济林组>速生阔叶树组〉灌木组;②除马尾松组和中生阔叶树组外,各优势树种小班的碳储量主要集中分布在0~100t的区域内,且与人类活动呈负相关。 相似文献
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云南松林区的林火与火险等级分区初探 总被引:1,自引:0,他引:1
云南松林区发生的森林火灾是多种自然因素和人为活动综合作用的结果。通过对四川省云南松分布区不同区域与林火有关的主要气候因子分析及综合值的比较,结合地形地貌、植被状况和人为活动等多种因素,将我省云南松分布区划分成5个不同等级的火险区,并提出了相应的护林防火对策。 相似文献
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Kostas S. Poirazidis Konstantina Zografou Panagiotis Kordopatis Dionissios P. Kalivas Margarita Arianoutsou Dimitrios Kazanis Evangelia Korakaki 《Annals of Forest Science》2012,69(4):519-529