第一篇：淺議重點生態(tài)公益林中幼齡林撫育及低效林改造現(xiàn)狀及前景

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淺議重點生態(tài)公益林中幼齡林撫育及低效林改造現(xiàn)狀及前景

作者：趙鳳杰 李延民

來源：《新農(nóng)村》2012年第13期

近年來，國家對林業(yè)建設(shè)非常重視。啟動實施了六大林業(yè)工作目標(biāo)，加大了造林綠化力度，加快了國土綠化進(jìn)程。但是，林子越多，撫育的任務(wù)越重。目前，我國現(xiàn)有人工林面積0.47×108hm2，其中林分面積0.31×108hm2，中幼齡林面積0.26×108hm2，占林分總面積的84%，形成了以中幼齡林為主體的森林資源分布格局，這些中幼齡林都亟需實施撫育間伐。長期以來，由于多種原因，經(jīng)營主體開展中幼齡林撫育及低效林改造積極性不高，使得中幼齡林撫育與低效林改造成為林業(yè)工作最薄弱的環(huán)節(jié)，森林結(jié)構(gòu)和質(zhì)量問題十分突出。主要表現(xiàn)是純林多，密度大。全國以馬尾松、杉木、楊樹為主的人工純林占全國人工林總面積的58.8%，混交林僅占7.9%。有的人工林分每公頃密度高達(dá)15000株以上，既嚴(yán)重影響林木正常生長，增加了森林火災(zāi)和病蟲害隱患。全國每年森林病蟲害發(fā)生面積達(dá)800×104hm2，森林火災(zāi)頻繁，火險等級提高，災(zāi)害加劇。其主要原因是大面積林分密度大、結(jié)構(gòu)差的森林不能得到及時撫育。

中幼齡撫育及低效林改造是培育森林的重要措施，也是林業(yè)生產(chǎn)的重要組成部分。從2005年開始，我國開始在東北、東南沿海、中南、西南等森林資源相對豐富的地區(qū)實施國家重點生態(tài)公益林中幼齡林撫育項目，以優(yōu)化生態(tài)公益林林分結(jié)構(gòu)，提高森林質(zhì)量和效益。重點實施地區(qū)包括北京、河北、黑龍江、浙江、安徽、福建、江西、山東、河南、湖北、廣東、廣西等23?。ㄗ灾螀^(qū)、直轄市）、四大森工集團(tuán)的37個縣（局）。

全國計劃安排中幼齡林撫育1.69×104hm2，單位面積投資標(biāo)準(zhǔn)1500元/hm2（100元/畝）。國家投資主要用于除草割灌、定株修枝、撫育間伐、間伐物運輸、林地清理、作業(yè)設(shè)計、檢查驗收等方面，按照國家有關(guān)規(guī)定適當(dāng)提取一定比例資金用于作業(yè)設(shè)計、檢查驗收。主要任務(wù)是對過密、過純的國家重點生態(tài)公益林進(jìn)行有效撫育。對過密、過純的國家重點生態(tài)公益林進(jìn)行有效撫育，旨在優(yōu)化林分結(jié)構(gòu)，提高林分質(zhì)量，培育健康森林，防止森林火災(zāi)、病蟲害發(fā)生，使森林生態(tài)、經(jīng)濟(jì)和社會統(tǒng)合效益得到正常發(fā)揮，促使林業(yè)全面協(xié)調(diào)可持續(xù)發(fā)展。

國家重點生態(tài)公益林撫育及改造項目是以發(fā)揮林分的最大生態(tài)效益為主要目的，以建立比較完備的林業(yè)生態(tài)體系和基本實現(xiàn)林業(yè)現(xiàn)代化為目標(biāo)，以提高生態(tài)公益林資源質(zhì)量和改善生態(tài)環(huán)境為重點，遵循森林自然演替規(guī)律，依靠科技，采取撫育、補(bǔ)植、封育、保護(hù)相結(jié)合的措施，把生態(tài)公益林建設(shè)成多林種、多樹種、多層次，結(jié)構(gòu)合理、功能健全，生態(tài)效益、社會效益、經(jīng)濟(jì)效益長期穩(wěn)定的森林生態(tài)體系。

第二篇：加強(qiáng)林場中幼林撫育及低質(zhì)林改造是恢復(fù)森林生態(tài)的有效途徑

加強(qiáng)林場中幼林撫育及低質(zhì)林改造是恢復(fù)森林生態(tài)的有效途徑 摘 要：森林生態(tài)系統(tǒng)只有保持結(jié)構(gòu)和功能的完整性，并具有抵抗和恢復(fù)能力，才能長期為人類社會服務(wù)。本篇著重論述了加強(qiáng)森林撫育及低質(zhì)林改造是恢復(fù)森林生態(tài)的有效途徑及其可行性和必要性。

關(guān)鍵詞：森林撫育； 低質(zhì)林改造； 森林質(zhì)量； 生態(tài)

一個森林生態(tài)系統(tǒng)只有保持了結(jié)構(gòu)和功能的完整性，并具有抵抗和恢復(fù)能力，才能長期為人類社會提供服務(wù)。但是由于人類的干擾導(dǎo)致森林生態(tài)系統(tǒng)的原有結(jié)構(gòu)被破壞，從而致使森林生態(tài)系統(tǒng)退化，引起水土流失、土壤退化、洪災(zāi)等等。由于植被遭到破壞，坡地表面的土壤受到暴雨沖擊，土壤孔隙被堵，雨水下滲速度隨之減少，形成大量徑流順坡而下，同時帶走大量表土、養(yǎng)分，使這些地區(qū)變成“走水、走土、走肥”的三走之地，土壤有機(jī)質(zhì)含量降低，N、P、K等元素缺乏。因此，應(yīng)該從維護(hù)國家安全、維護(hù)人類自身安全的角度出發(fā)認(rèn)識維護(hù)森林生態(tài)安全的重要性，建立與健全森林生態(tài)系統(tǒng)安全保障體系，為社會、經(jīng)濟(jì)、環(huán)境的可持續(xù)發(fā)展提供不可缺少的基礎(chǔ)。

森林質(zhì)量的下降是導(dǎo)致生態(tài)環(huán)境惡化的根源

大崗林場的森林是鎮(zhèn)賚縣西北的天然屏障。近年來，隨著國民經(jīng)濟(jì)的持續(xù)增長和經(jīng)濟(jì)實力的進(jìn)一步提高，工業(yè)化水平的提高和人口的高速發(fā)展，生態(tài)環(huán)境惡化，自然災(zāi)害頻繁。僅從大崗林場來看，全場水土流失面積已由90年代的500 hm?擴(kuò)大到目前的1300 hm?。農(nóng)業(yè)抗災(zāi)能力十分脆弱，全場水旱成災(zāi)率較高。由于生態(tài)環(huán)境惡化，風(fēng)、沙、旱成災(zāi)面積逐年增加，環(huán)境污染加劇，嚴(yán)重影響了我場農(nóng)業(yè)和國民經(jīng)濟(jì)的發(fā)展及人民生活水平的提高。我們從第五次森林資源清查來看，導(dǎo)致生態(tài)環(huán)境惡化的一個重要原因就是森林資源的破壞，嚴(yán)格地說是森林質(zhì)量的降低，既森林的林分結(jié)構(gòu)、森林公頃蓄積量的降低。建場初期，有林地面積為9000多公頃，蓄積38萬m?，每公頃平均蓄積量為40 m?，森林覆蓋率為36.9%。而目前全場有林地面積為11300 hm?，蓄積30萬m?，每公頃平均蓄積量為26.5 m?，森林覆蓋率為41.9%。從上述數(shù)據(jù)來看，多年來森林面積增加而公頃蓄積下降，說明了多年來環(huán)境惡化的根本原因是森林林分質(zhì)量的降低。也進(jìn)一步論證了專家的測算，即當(dāng)森林蓄積達(dá)到每公頃80 m?以上時，森林涵養(yǎng)水源等生態(tài)效能才能發(fā)揮的充分，而低于80 m?以下，生態(tài)效能相對來說是較為低下的理論。加快中幼齡林撫育、低質(zhì)林改造建設(shè)的可行性

2.1 在中幼齡林撫育、低質(zhì)林改造中確立的一系列規(guī)章和政策

我們從90年代開始在封山育林的基礎(chǔ)上，開展了中幼令撫育和低質(zhì)林改造工作，制定了《大崗林場森林撫育、改造技術(shù)規(guī)程》。近幾年來，我場針對幼齡林面積大，等待撫育的林分多的特點，制定了諸多有利于幼齡林撫育的政策.如：“撫育的小材小料可以抵撫育的工資”，“不安排撫育的不允許進(jìn)行主伐’。并制定了《人工林撫育技術(shù)細(xì)則》，把人工幼林撫育列入了計劃，促進(jìn)了中幼齡林撫育、低質(zhì)林改造工作的開展，并在已開展的中幼齡林撫育、低質(zhì)林改造活動中積累了一定的經(jīng)驗。

2.2 中幼齡林撫育、低質(zhì)林改造建設(shè)中的經(jīng)驗

在幾十年的森林經(jīng)營中，積累了一定的經(jīng)驗。如1998年對皆伐后天然更新起來的中幼齡林進(jìn)行生長撫育，3年進(jìn)行了調(diào)查得出如下數(shù)據(jù):撫育的林分平均胸徑每年凈生長為1.08 cm，而未撫育的林分平均胸徑每年凈生長僅為0.3 cm，林分公頃蓄積則分別為130 m?和90 m?。

2.3 中幼鈴林撫育、低質(zhì)林改造建設(shè)效益顯著

2.3.1

生態(tài)效益

森林撫育、低質(zhì)林改造不但能改善林分結(jié)構(gòu)，提高森林質(zhì)量，而且有利于改善林分的衛(wèi)生狀況，增強(qiáng)抗御自然災(zāi)害的能力。據(jù)研究，在幼、中令林階段，由于林木密度較大，降雪后承受雪的壓力比密度低的林分大，每公頃林冠受到雪壓的重量可達(dá)500多t，林木胸高斷面上每平方厘米承受的壓力達(dá)2.5 kg；林木稀疏后，每公頃林冠受到雪壓的重量可降到300多t，林木胸高斷面上每平方厘米承受的壓力可降至0.5 kg。由于森林撫育、低質(zhì)林改造改善了林分的衛(wèi)生狀況，病蟲害可下降90%以上，增強(qiáng)了抗災(zāi)的能力。

2.3.2

經(jīng)濟(jì)效益

中幼齡林撫育投入少，見效快，在一個森林經(jīng)營周期內(nèi)(10年)撫育林分與未撫育林分，林分生長量年凈增每公頃3 m?，10年凈增蓄積量30 m?，新增木材產(chǎn)值9000元/公頃(按300元/公頃計算)，是森林撫育費用900元/公頃的10倍。如果將全場1萬多公頃的森林全部撫育一遍，每年至少可凈增蓄積量3萬m?，新增木材產(chǎn)值900萬。

2.3.3

社會效益

中幼齡林撫育工程不僅緩解了大中徑級后備森林資源的不足，而且壯大了林業(yè)產(chǎn)業(yè)，增加了職工收人。森林撫

育和改造投入資金的70%可轉(zhuǎn)化為勞務(wù)收人，以年撫育和改造1000hm?計算，年均投資90萬元，相當(dāng)于每年可吸納近萬個剩余勞動力，社會效益顯著。加快中幼齡林撫育、低質(zhì)林改造建設(shè)的必要性

3.1 加快中幼齡林撫育、低質(zhì)林改造建設(shè)是提高森林資源數(shù)量和質(zhì)量的迫切需要

目前由于未能采取切實有效的撫育和改造等培育措施，致使部分中幼齡林因單位面積株數(shù)太多，密度過大，生長不良，嚴(yán)重影響了林分的質(zhì)量;部分中幼齡林雜草叢生，霸王樹、灌木等非目的樹種占據(jù)主要生長空間。嚴(yán)重制約著目的樹種的生長，影響林木的生長發(fā)育;部分中幼齡林因自然稀疏，枯死木急劇增多，枯立木比重顯著提高，為森林病蟲害的發(fā)生和蔓延提供了場所，為森林火災(zāi)、雪壓、風(fēng)倒等自然災(zāi)害創(chuàng)造了條件;部分中幼齡林因公頃株數(shù)太少、林分質(zhì)量低，影響了林地生產(chǎn)力的發(fā)揮，影響了森林效益的發(fā)揮。而加強(qiáng)森林撫育和改造，可以改善林分生長條件，促進(jìn)林木生長，據(jù)調(diào)查，撫育后的林分生長率可提高了6.8%，提高了林分的生產(chǎn)力和森林資源的質(zhì)量。

3.2 加快中幼齡林撫育、低質(zhì)林改造工程建設(shè)是充分發(fā)揮森林各種功能的需要

我們曾對不同的林分進(jìn)行了調(diào)查研究，結(jié)果發(fā)現(xiàn)不同林分其生態(tài)效益發(fā)揮的差異較大。正是進(jìn)行了森林結(jié)構(gòu)和類型的調(diào)整，改善了林木生長發(fā)育的生態(tài)環(huán)境條件，促進(jìn)了林分質(zhì)量的提高，增加了森林的整體效能，使森林的多種效能得到了充分發(fā)揮。

3.3 加快中幼齡林撫育、低效林改造建設(shè)是況固造林綠化成果的

需要

多年來，國家集中人力、物力、財力，大抓造林綠化建設(shè)取得重大進(jìn)展，但是存在一個非常重要的問題，就是保存率太低，影響了造林綠化成果。對我場的更新造林進(jìn)行了普查，結(jié)果是保存率僅為65.2%，目前在加強(qiáng)更新造林的基礎(chǔ)上，必須加速進(jìn)行森林的撫育和改造，提高造林的成活率、保存率、成林率。

3.4 加快中幼齡林撫育、低質(zhì)林改造工程建設(shè)是強(qiáng)化森林經(jīng)營管理的需要

長期以來，我們對森林經(jīng)營這一關(guān)鍵環(huán)節(jié)沒有給予足夠的重視。由于沒有投資，加上管理工作滯后，致使撫育、改造工作欠賬十分嚴(yán)重。為了扭轉(zhuǎn)這種狀況，必須加強(qiáng)森林經(jīng)營工作，抓緊進(jìn)行中幼令林撫育和改造工程的建設(shè)。

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A forest ecosystem is only to keep the integrity of the structure and function, and has the resistance and resilience, can provide service for

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human society in the long run.But caused due to human disturbance of forest ecosystem destroy structures, thus causing degraded forest ecosystems, cause soil erosion, soil degradation, floods and so on.Due to vegetation destroyed, soil impacted by heavy rain on the surface of the slope, soil pore blocked, less rain infiltration rate, down a lot of runoff formation, at the same time take away a large number of top soil, nutrients, make the region into a “slice, go, go fat” SanZou land, soil organic matter content is reduced, lack of N, P, K and other elements., therefore, should from safeguarding state security, maintain human security Angle to know the importance of maintaining forest ecological safety, establish and improve the forest ecological system security guarantee system, for the sustainable development of society, economy and environment indispensable foundation.a drop in the quality of forest is the root of leads to the deterioration of the ecological environment

DaGang forest farm in the forest is a natural barrier town county northwest of adlai was in charge.In recent years, with the steady growth of national economy and economic strength to further improve, the improvement of industrialization and the rapid development of population, the deterioration of ecological environment and frequent natural disasters.Only from the point of DaGang forest farm, to the area of soil and water loss has been in the 90 s from 90 hm? Expanded to the current 1300 hm?.http://004km.cn/

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Vulnerable agricultural disaster, severe hazard rate is higher.Due to the deterioration of ecological environment, wind, sand and drought inundated area increased year by year, the environmental pollution, serious influence the development of my field of agriculture and national economy and the improvement of people's living standards.We from the fifth forest resource inventory, leads to the deterioration of the ecological environment is an important reason why the destruction of the forest resources, lower quality strictly, a forest, forest stock volume of forest structure, forest ha already reduced.Early construction field, the forestland area of more than 9000 hectares, 380000 m? , the average volume per hectare of 40 m? , the forest coverage rate of 36.9%.And the whole forestland of 11300 hm? , 300000 m? , the average volume per hectare is 26.5 m? , the forest coverage rate of 41.9%.From the above data, forest area increases with the ha decline for years, shows that over the years, the root cause of environmental degradation is the forest stand quality decreased.Further demonstrated the calculations, the experts when forest accumulation reached 80 m per hectare? Above water conservation forest ecological efficiency, such as to play fully, and less than 80 m? , under the theory of ecological efficiency is relatively low.2 to speed up the construction feasibility of transforming sapling forest, low-quality forest

2.1 in the young forest tending, low-quality forest reform established a

series of regulations and policies in the us since the 90 s on the basis of afforestation, carried out in young to cradle and low-quality forest reconstruction work, formulated the “technical specification” DaGang forest farm forest tending, reconstruction.In recent years, I field in young forest area is large, waiting for tending stand more characteristic, established many of sapling forest policy.Such as: “the cradle of the little wood material can be arrived in raising wages”, "don't arrange tending does not allow for final felling.'and set the rules of plantation tending technology, include artificial young forest tending on the plan, promoted in the young forest tending, low-quality forest reconstruction work, and has been carried out in the young forest tending, forest of low-quality renovation accumulated certain experience in the activities.2.2 sapling forest, low-quality forest reform in the construction experiences in decades of forest management, accumulated certain experience.Such as 1998 years for natural regeneration after clear cutting up the are grown, young forest tending, three years has carried on the survey data as follows: raise the stand average diameter at breast height net growth each year to 1.8 cm, tending stand average diameter at breast height of annual net growth of only 0.3 cm, stand ha accumulation is 130 m respectively? And 90 m?.2.3 in the young forest tending, low-quality forest bell renovation construction benefit is remarkable

2.3.1 ecological benefit forest tending, low-quality forest transformation can not only improve the stand structure, improve the quality of forest, and to improve forest health condition, enhance the ability of resistance to natural disasters.According to research, makes forest stage, in the young, because of its high density of trees, snow snow pressure after bigger than low stand density, canopy per hectare is the weight of the snow pressure can reach more than 500 t, every square centimeter on trees chest high section pressure up to 2.5 kg;Sparse trees, each hectare canopy under the weight of the snow pressure to be more than 300 t, trees chest high profile per square centimetre of under pressure can drop to 0.5 kg.Because the forest tending, low-quality forest reform improved the health of forest stand, plant diseases and insect pests can be decreased by more than 90%, enhances the ability of the disaster.2.3.2 economic benefits in the young forest tending less investment, quick effect, in a forest management cycle(10 years)bare stand and tending forest, forest stand growth in net 3 m per hectare? Net increase of volume of 30 m, 10 years? Output value of 9000 yuan/ha, new wood(press)of computation of 300 yuan/ha, forest tending cost is 10 times as much as 900 yuan/ha.If all will be full of more than 10000 hectares of forest tending, annual net increase of volume of at least 30000 m? Output value of 9 million, the new wood.2.3.3 social benefits in the sapling forest engineering not only relieves the

large and medium size level backup the shortage of forest resources, and expand the forestry industry, increased the worker income.Forest tending and 70% of the money can be converted into labor income, tending and upgrading 1000 hm? Computation, an annual investment of 900000 yuan, equivalent to a year to absorb nearly all surplus labor, social benefit is remarkable.to speed up the construction of young forest tending, low-quality forest transformation in necessity

3.1 to speed up the construction of sapling forest, low-quality forest reform is to improve the urgent needs of the quantity and quality of forest resources at present due to the failure to take effective parenting and reforming the cultivating measures, such as the part in the young forest because of the number per unit area is too much, too much density, grow bad, seriously affect the quality of the forest;Overlord weeds in part sapling forest, trees, shrubs and nontarget species occupied the main growth space.Severely restricts the objective tree growth, affect forest growth and development;Part due to the natural thinning of sapling forest, unthinned stands sharp increase, considerably increase the proportion of dry wood, for the occurrence and spread of forest diseases and insect pests, such as forest fire, snow pressure, and wind down created the condition for natural disasters;Part number is too little for ha of sapling forest, the forest stand quality low, influence the exertion of forest land

productivity, forest benefit is greatly influenced.And strengthening forest tending and transformation, can improve the stand growth conditions, promote the growth of forest trees, and according to the survey, after raising the forest stand growth rate can be increased by 6.8%, improve the quality of the forest productivity and forest resources.3.2 accelerate the reform of sapling forest, low-quality forest in engineering construction is the need of forest functions into full play we have conducted a study of different forest stand, found that different forest it play the differences of ecological benefits.Adjustment of forest structure and type, improved forest tree growth and development of the ecological environment, promoting the improvement of the forest stand quality, increase the overall efficiency of the forest, the forest of a variety of performance got into full play.3.3 accelerate the reform of sapling forest, the low efficiency in construction is KuangGu afforestation achievement needs over the years, countries concentrate manpower and material resources, financial resources, high holding afforestation construction made great progress, but there is a very important problem, BaoCunLv is too low, affected the afforestation achievement.For my field survey, the reforestation of the results is BaoCunLv is only 65.2%, currently on the basis of strengthening reforestation, must accelerate forest tending and renovation, increase the rate of afforestation survival rate, and forest.3.4 accelerate the reform of sapling forest, low-quality forest in engineering construction is the need of strengthening forest management for a long time, we are a key link on forest management did not give enough attention.Because there is no investment, and management lag, cause tending, reconstruction work very serious debt.In order to reverse this situation, must strengthen forest management work, with the young forest tending and project construction.