| 关于我国人工林长期生产力的保持 |
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| 引用本文： | 盛炜彤.关于我国人工林长期生产力的保持[J].林业科学研究,2018,31(1):1-14. |
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| 作者姓名： | 盛炜彤 |
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| 作者单位： | 中国林业科学研究院林业研究所, 北京 100091 |
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| 摘 要： | 为了保持我国人工林的长期生产力和提高森林质量,达到可持续经营的目的。作者在以往研究工作的基础上,广泛收集了国内外有关成果与资料,概括论述了我国人工林森林生产力的现状、不能保持生产力的原因与机理以及长期保持人工林生产力的技术对策。按第八次清查的全国森林资源数据,每公顷蓄积量为89.79 m^3,其中天然林为104.6 m^3,人工林为52.76 m^3,人工林森林生产力明显低于天然林;我国优势树种人工林每公顷蓄积量也不高,如杉木为69.8 m^3,马尾松为56.2 m^3,落叶松为58.6 m^3,这些数据比日本2002年3月公布的人工林相似树种的数据低很多,如日本针叶树蓄积量为227.97 m^3·hm-2,柳杉为295.83 m^3·hm-2,落叶松为189.88 m^3·hm-2。关于年生长量,按全国第七次资源清查的中龄林与近熟林的数据做统计:杉木人工林5.2~4.2 m^3·hm-2,马尾松为3.2~1.8 m^3·hm-2,柏木为3.4~3.2 m^3·hm-2;但按作者掌握的我国重点或示范性、试验性小面积人工林生长量看,却很高,按我国编制的速生丰产林标准的生长量数据看比较高。我国大面积人工林生产力不高,短周期经营的杨树、桉树人工林也不高,主要原因是:(1)纯林化与针叶化严重。按第八次全国森林资源统计,纯林占人工林的85%,而且针叶化明显,人工乔木林10个优势树种中针叶林比例高达56.9%。人工纯林结构简单,生物多样性低,生物学上缺乏稳定性。人工纯林特别是针叶纯林,抗性低,抗自然灾害和大气污染能力均差,人工纯林维护地力的能力也弱。(2)集约育林的技术措施:立地控制技术未得到推广,适地适树适品种原则在育林中未能认真贯彻;密度、植被、地力控制技术也执行不力,大面积上的人工林仍属于粗放经营;连作引起林地土壤理、化、生物特性恶化,土壤质量衰退,导致林木生长不良,林分生产力逐代下降;造林作业造成水土流失,如杉木造林,传统的育林技术未得到明显改进,福建尤溪炼山后进行的3年观测结果表明,炼山和水土流失损失的有机质高达989.35 kg·hm-2,养分586.26 kg·hm-2。桉树在砖红壤进行的机耕整地,水土流失也很严重,不合理的造林作业,最终导致土壤质量与森林生产力下降。短周期培育人工林带来了2个重要问题,一是对林地肥力要求高,二是如何利用无性系才能保持长期生产力。短周期经营采用的无性系,生长速度快,生长量大,轮伐期短,养分需求量大,如刚果12号W5无性系,通常利用地上部分,以5~7 a的轮伐期计,消耗的养分达571.75 kg·hm-2,我国培养短周期人工林的土壤质量本底原本普遍不高,如果采取连作,土壤有机质养分会明显下降,土壤质量衰退,并对其功能产生危害。我国杨树、桉树等人工林要达到短周期持续经营,还需要实行多无性系造林。我国人工林长期生产力保持的技术对策,应采取先进的集约育林措施,包括遗传控制、立地控制、密度控制、植被控制与地力控制。
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| 关 键 词： | 人工林 长期生产力 可持续经营 生态系统管理 |
| 收稿时间： | 2017/10/10 0:00:00 |
On the Maintenance of Long-term Productivity of Plantation in China |
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| SHENG Wei-tong.On the Maintenance of Long-term Productivity of Plantation in China[J].Forest Research,2018,31(1):1-14. |
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| Authors: | SHENG Wei-tong |
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| Institution: | Research Institute of Forestry, Chinese Academy of Forestry, Beijing 100091, China |
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| Abstract: | This paper aims at maintaining the long-term productivity of plantations and improve the stand quality so as to achieve the sustainable management of plantation. Related research achievements and data at home and abroad were collected, and the following topics were discussed:the present situation of the plantations productivity in China, the reason and mechanism that the long-term productivity of plantations was not sustained in China, and the technical countermeasures for maintaining the long-term productivity of plantations in China. According to China''s eighth national forest resources inventory, the productivity of plantation is obviously lower than that of the natural forest. The stand volume of dominant tree species in plantation is much lower than that of similar tree species in Japan. The lower productivity of plantation occurred mainly in large-areas plantations and the short-rotation poplar and eucalypt plantations in China. The reasons and mechanism of low productivity of forest plantation in China could be concluded as follows:1. pure forests and conifer plantations taking the majority, 2. The inappropriate intensive technical measures of forest cultivation, and 3. short-rotation plantation cultivation creating problems, such as decline of soil fertility in forest plantation, and monoculture of elite clones. The short-rotation plantations usually need high quantity and efficiency supply of nutrient with their characteristics of fast growing, larger volume increment, and shorter harvesting rotation. Since most of the sites for developing short-rotation forest plantations have poor soil conditions in China, the soil organic matters and nutrient will decrease significantly if successive cropping was adopted, which will bring about degradation of soil function. In order to achieve sustainable management of clonal poplar, eucalypt and other plantations in China, it is also necessary to carry out afforestation with multiple clones to avoid the negative effects due to the narrow adaptability range of few clones. In this paper, the author suggests that advanced intensive cultivation measures should be applied, i.e. genetic control, site control, stand density control, vegetation control and soil fertility control. |
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| Keywords: | plantation long-term productivity sustainable management ecosystem management |
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