基于蓄积生长率的蒙古栎天然次生林抚育间伐研究

[目的]探讨蒙古栎各龄组适宜的抚育间伐方案,为吉林省蒙古栎天然次生林的抚育间伐提供依据。[方法]以5期吉林省森林资源连续清查数据为基础,筛选蒙古栎幼龄林、中龄林和近熟林,划分5级蓄积间伐强度:强度1(0~10%)、强度2(10%~20%)、强度3(20%~30%)、强度4(30%~40%)、强度5(40%~50%),对比未间伐林分,研究不同龄组林分对不同间伐强度在各观测间隔(5、10、15和20 a)的蓄积生长率的变化规律。[结果](1)伐后各时间段蓄积生长率随间伐强度增长的趋势:幼龄林先持平,再快速上升,最后快速下降;中龄林先缓慢增长,最后快速下降;近熟林,伐后5 a与10 a,先快速增长,后快速下降直至平缓,而伐后15 a与20 a,先快速增长,后平缓下降。(2)伐后各时间段峰值出现的间伐强度范围:幼龄林都在20%~35%之间,中龄林由伐后5 a和10 a的15%~35%之间至伐后15 a与20 a的20%~40%之间,近熟林由伐后5 a和10 a的15%~25%之间至伐后15 a与20 a的15%~35%之间。(3)各间伐强度级蓄积生长率均值相对于未间伐提升显著的有:幼龄林:强度3与强度4;中龄林:强度2、强度3和强度4;近熟林:强度2和强度3。(4)随着时间的推移,不同间伐强度与未间伐之间的蓄积生长率的差异越来越小。[结论]吉林省蒙古栎天然次生林,各龄组适宜的间伐强度:幼龄林为25%~35%;中龄林为20%~35%;近熟林为15%~30%。     

绥宁县用材林林龄结构优化研究

针对绥宁县用材林林龄结构现状,应用系统动力学原理对用材林林龄结构优化进行建模,通过计算预测在不同采伐模式下用材林蓄积保有量和出材量的变化,从而找出最优的采伐模式。结果表明:用材林最优采伐模式即轮伐期为40年,择伐周期为15年,择伐强度为30%,抚育间伐周期为15年,抚育强度为15%。在这种优化模式下,到2025年绥宁县用材林蓄积保有量将达到10 186 848 m3,出材量将达到249 006 m3,使用材林发展达到生态效益和经济效益兼顾的最优状态。     

Multipurpose conversion management of Scots pine towards mixed oak–birch stands—A long-term simulation approach

The forest growth model 4C was used to investigate how conversion management of a Scots pine (Pinus sylvestris L.) stand towards a mixed oak–birch stand would affect stand structural development – and hence biodiversity and productivity – in the long term. For this purpose the 4C model was parameterised for natural regeneration of light demanding species and extended for management of multi-layered stands. A series of structural indicators was selected to describe key factors of forest biodiversity at the stand scale. Two consecutive aspects of Scots pine conversion were tested: (1) the choice of conversion strategy between thinning and gap creation and (2) the choice of conversion regime in terms of cutting cycle, thinning type and pine tree retention. Three simulated conversion strategies aim at the gradual removal of the pine canopy but differ in the spatial organisation of pine cuttings and hence result in different light conditions for regeneration. Only the directed gap creation strategy was able to maintain and increase birch admixture to the stand and to approach natural stand structural development. Simulation of 12 conversion regimes for the directed gap creation strategy indicated that thinning type (from above or from below), pine tree retention at final felling (50% of the standing volume or none) and cutting cycle (6, 9 or 12 years) all significantly influence stand structural development. These effects were clearest for oak development. Birch occurred in a few mixed clusters, but tended to disappear when longer cutting cycles were used. Based on a multi-criteria analysis we conclude that the optimal conversion regime – in which both stand productivity and biodiversity objectives can be combined – implies thinning from above, pine tree retention, and cutting cycles of 6 years. The conceptual validity of the model as well as the applicability of the results are discussed.     

桂西南马尾松人工林生长对不同强度采伐的动态响应

[目的]研究不同强度采伐下马尾松的生长动态,筛选适宜的采伐强度,为马尾松人工林近自然经营提供技术支撑。[方法]2007年10月在14年生马尾松人工林(保存密度1 100株·hm~(-2))内进行采伐试验,设置4个采伐强度,即保留密度分别为225、300、375、450株·hm~(-2),以不采伐为对照;其后,自2008年开始连续8 a,每2 a测定1次马尾松的胸径、树高、枝下高和冠面积等生长指标,并计算单株材积和林分蓄积量,应用方差分析和Duncan多重比较分析生长指标对不同采伐强度的动态响应。[结果]表明:采伐强度显著影响林分生长,其中,林分平均胸径、单株材积、冠面积的年均增长量随保留密度增大而减小,但均显著高于对照(P0.05)。采伐后第1 3年,马尾松冠面积增长量显著高于采伐后期,胸径则在采伐后第3 5年最高,而不同采伐强度对林分树高生长影响不明显。保留密度显著影响林分枝下高和蓄积量的动态变化,其年均增长量随密度增大而递增。5个处理间林分蓄积年均增长量的差异随林龄的增大而逐渐缩小。[结论]马尾松人工林生长对不同强度采伐的动态响应以树冠最敏感,冠面积首先陡然增大,进而引起胸径的快速生长。树高和枝下高在采伐后年均增量变化相对平稳。4个采伐强度均显著促进单株材积生长,而仅保留密度为225株·hm~(-2)的采伐对林分蓄积增长量影响显著。综合比较林分的单株材积和林分蓄积连年增长量,建议在桂西南15年生马尾松人工林近自然经营中宜选择300株·hm~(-2)的保留密度进行采伐。     

北亚热带不同森林群落类型的生物多样性研究

北亚热带地区的人工针叶纯林可以通过抚育间伐或者封山育林等措施大大加快其向着该地区的顶级群落方向演替。该地区几种典型群落的乔木层生物多样性指数大小依次为：针阔混交林〉〉常绿阔叶纯林〉马尾松纯林（郁0.5）〉马尾松纯林（CK组）〉杉木纯林（修枝）〉杉木纯林（间伐10%）;灌木层生物多样性指数大小排序为：马尾松纯林（CK组）〉杉木纯林（间伐10%）〉杉木纯林（修枝）〉常绿阔叶纯林〉马尾松纯林（郁0.5）〉针阔混交林。     

马尾松台湾相思混交造林技术研究

指出了对杉木采伐迹地改造,营造马尾松台湾相思混交林、纯林,经过施肥、抚育,十几年的经营管理,林木生长良好。混交林生长林分与纯林生长林分相比,经调查显示:13年生马尾松台湾相思混交林的林分生长平均树高、胸径、树冠、蓄积量,分别比马尾松、台湾相思纯林的林分树高提高2.43%、12.46%,胸径粗6.3%、12.71%,蓄积量多11.92%、36.84%。能增加土壤养分全量含量,提高土壤肥力。     

Carbon sequestration of naturally regenerated Aleppo pine stands in response to early thinning

Sustainable forest management ought to include the production of non-use value, mainly in forests with low value of direct production. Predictions on climate change points out increase in aridity and changes in fire regime (increasing fire risk, recurrence and severity), particularly in the Mediterranean Basin. However, we have to question whether this implies a decrease in forest resilience and productivity. In summer 1994, large forest fires burned a huge surface of Aleppo pine stands in Spain. In areas naturally regenerated, we carried out early thinning and sampled 18 plots. In winter 2008 and 2009, we inventoried all pine trees in sampling plots, recording total height, diameter and canopy cover for scaling-up results to stand-level estimation. In addition, we destructively sampled 54 individual pine trees, selecting various thinning and dating treatments, to measure and estimate biomass and partitioning. The date of thinning influenced allometric relationships, earlier thinning stimulated the productivity of individual pine saplings, increasing the three components of carbon intake. Although, the total net carbon value was lower in almost all thinned plots (at least for short periods after thinning), differences were actually found depending on the cutting age and thinning severity. Control and thinned plots (mainly those thinned earlier and heavier) showed similar amounts of carbon but comprised in a low number of living trees with high productivity. Thus, productivity and carbon storage assessment should be monitored, in the long-term, to check prediction of proposed models for evaluation on early treatments.     

Thinning effects on carbon allocation to fine roots in a Quercus ilex forest

The dynamics of the fine root system are relevant to calculations of the carbon balance of the ecosystem, and there is also a need to quantify changes in this component caused by disturbances. Mediterranean forest systems have historically been coppiced to obtain charcoal. As a result of the resprouting capacity of holm oaks (Quercus ilex L.), these forests present more than 50% of their biomass below ground (stump + roots > 1 cm in diameter), but the effects of thinning on the fine root system are unknown. Fine root biomass, production, mortality and longevity were studied in a control and a thinned Mediterranean holm oak forest by minirhizotron methodology. Observations of fine roots started 2 years after thinning and continued for almost 3 years. Extraction of 80% of the former basal area of the forest greatly affected carbon allocation patterns. Biomass increased by more than 100%, production increased by 76%, mortality increased by 32% and longevity decreased by around 2 weeks. The greatest differences between treatments were associated with differences in growth during autumn months in the top 40 cm of soil, particularly between 10 and 20 cm depth.     

不同间伐强度对人工阔叶红松林生长的影响

文章针对不同间伐强度对人工阔叶红松林生长的影响进行了调查研究。结果表明:阔叶树胸径生长和蓄积增长率随间伐强度加大而增加,但对树高的影响较小;间伐强度的增大会明显促进红松胸径和树高的生长,但是首次抚育间伐会使当年的树高生长量显著降低,以后随林龄的增加树高生长量会逐渐恢复正常生长;中度间伐措施对阔叶树和红松的生长均比较有利,10a生的阔叶红松林实施上层抚育的适宜间伐强度为45%左右;中度间伐的林分由于资源水平适中(主要是光资源),因而有利于林下植被均匀度和多样性的提高。     

Comparison of stand dynamics after dieback caused by pine wilt disease among pine forests with different management regimes in western Japan

In pine forests damaged by pine wilt disease, in western Japan, the effect of protection regimes of pine trees on the stand dynamics were examined in the following four stands: (1) lightly damaged stand (age 30–40 years) with no procedure in operation for protecting pine trees; (2) severely damaged stand (age 30–40 years) with no procedure in place for protecting pine trees; (3) severely damaged stand (age 50 years) with a selective cutting of infected trees; (4) severely damaged stand (age 30–40 years) with a selective cutting of infected trees. All the stands had been abandoned before the pine wilt disease damage. The understory structure of the severely damaged stand with no protection procedure was similar to that of the lightly damaged stand. Frequent invasion by tree species and acceleration in the growth of understory trees occurred after the dieback in the selective cutting stand. These results suggest that a deficiency in the canopy layer caused by the dieback resulted in low disturbance intensity in the early stages after the dieback, but the selective cutting increased the intensity by the reduction in the understory as well as the canopy layer. The intensity of the disturbance in the selective cutting stands was larger in the younger stand because it had a higher density of selectively cut pine trees. The different stand structure of pine forests occurred after the dieback because the intensity of the disturbance varied as a result of the selective cutting operation and the stand age.     

A succession and silviculture model for the broad-leaved Korean pine forests of Changbai Mountain Area

IntroductionGaPSinforestSwereoftenfomledduetobigtreesfalldown.Regenerationandgrowtl1inthegapsincreasebe-causeofIheAnprovementoflightcondition-Thegapwillbefilledwithnewregeneratedtrees.Wattnamedtl1isforesIdynamicsastheforestgrowtllcycle.SinceD.Bot-kindevelopedthefirstGapmo`Iel(JANOWAnlodel)basedontheforestgrowthcycletheory,dleresearchongapmodelbecameoneofthemostactivedirectio11slilecologybecauseofJANoWAnlodeI'ssuccess.H.Sl1ug-artandhisstUdentSmadegreatc()ntributio11stogapmodeI'sdeve…     

不同造林密度华山松人工林抚育间伐强度的选择研究

为确定不同造林密度形成的人工华山松林的合理抚育间伐强度和具体间伐措施,对不同间伐强度下2种不同密度人工华山松林的林木平均胸径、树高和单位面积蓄积变化进行研究。结果表明,一般密度华山松人工林间伐强度效果为:30%>35%>25%>45%>50%>20%>60%>10%>0%,保留株数以1 830株/hm2左右最好,在抚育间伐实施中采取3株中选伐1株与4株中选伐1株交替使用措施效果最好;密植华山松人工林间伐强度效果为40%>45%>35%>50%>30%>60%>25%>20%>10%>0%,保留株数以2 985株/hm2左右最好,在森林抚育实施中采取2株中选伐1株与3株中选伐1株交替使用效果最好。     

基于国家森林资源清查数据的不同生物量和碳储量估计方法的对比分析

[目的]通过对不同生物量和碳储量的估计方法进行对比分析,为确定在国家森林资源清查中生物量和碳储量的具体估计方法提供依据。[方法]以广东省2012年森林资源清查的100个杉木林和80个马尾松林的实测样地资料为基础,利用近年来我国建立的主要树种立木生物量模型,对改进IPCC法、生物量模型法和转换因子连续函数法(即方精云法)3种方法按一元和二元模型共6种方案进行了对比;同时,基于改进IPCC法一元和二元模型的生物量估计值,用平均含碳系数法、组分含碳系数法和固定含碳系数(0.5或0.47)法分别对碳储量进行估计。[结果]用二元生物量模型法得到的杉木林和马尾松林样地的总生物量分别为320 Mg和331 Mg,一元生物量模型法的结果分别相差0.9%和6.2%;改进IPCC法的估计结果,采用二元和一元模型时杉木林分别相差-3.6%和-11.9%,马尾松林分别相差-8.5%和-19.6%;而方精云法的估计结果,采用二元和一元模型时杉木林分别相差6.65倍和6.60倍,马尾松林分别相差-14.3%和-18.0%。平均含碳系数法和组分含碳系数法的碳储量估计结果,杉木林仅相差0.2%,马尾松林相差约0.4%;固定含碳系数法的估计结果因树种而异,对杉木林要低估0.6%5.4%,对马尾松林要低估3.3%9.1%。[结论]对生物量的估计,采用生物量模型法准确性最高,而林木水平的生物量模型其预估精度要高于林分水平的模型;IPCC法是基于材积源的通用方法,将其中的缺省参数改进为可变参数模型,可大大提高方法的适应性;方精云法只是基于IPCC法所建立的林分水平模型在大尺度上的一种具体应用方法,其精度要低于林木水平的生物量模型法,不适于中小尺度应用。对碳储量的估计,采用平均含碳系数法与组分含碳系数法差异很小,但采用固定含碳系数法则误差较大。     

柳杉人工林皆伐后初期土壤有机碳和微生物量碳动态

本文研究了华西雨屏区柳杉人工林皆伐后1年内土壤有机碳和微生物量碳动态。结果表明:柳杉人工林皆伐林地土壤平均有机碳含量比对照(未皆伐林地)减小2.01 gC.kg-1,但差异不显著,而土壤平均有机碳储量及微生物量碳分别比对照减少20.97 tC.hm-2、6.68 mg.kg-1(P0.05);皆伐林地土壤有机碳含量及微生物量碳均随季节的变化而逐渐降低,但有机碳储量随季节的变化无明显减少趋势;皆伐林地土壤四季的有机碳含量、碳储量和微生物量碳差异不显著。皆伐对柳杉人工林土壤有机碳储量的影响主要表现在0~20 cm土层(P0.05);皆伐林地和对照在0~40 cm土层的微生物量碳和有机碳含量都表现出显著相关性(P0.05),但对照的相关性高于皆伐林地。总之,柳杉人工林转变为采伐迹地后,其初期土壤有机碳储量和微生物量碳都明显减少。     

The effect of thinning on microbial biomass C, N and basal respiration in black pine forest soils in Mudurnu, Turkey

Reducing the canopy cover (e.g., forest thinning) is one of the most commonly employed forest silvicultural treatments. Trees are partially removed from a forest in order to manage tree competition, thus favoring the remaining and often the most valuable trees. The properties of the soil are affected by forest thinning as a result of changes in key microclimatic conditions, microbial communities and biomass, root density, nutrient budgets and organic matter turnover. The aim of this study was to determine the soil microbial biomass C, N and respiration (basal respiration) in a black pine (Pinus nigra Arn. subsp. pallasiana) forest in the Mudurnu district of Bolu Province (Western Black Sea Region, Turkey). Whereas forest thinning was found to cause increases in the soil temperature, microbial biomass C and N and organic C, it was found to decrease the soil moisture, basal respiration and metabolic quotient (qCO₂). As expected, soil organic C exhibited a strong impact on soil microbial biomass C, N and basal respiration. It was concluded that the influence of forest thinning on the microbial biomass and soil respiration was the combined result of changing microclimatic conditions and soil properties, such as forest litter, soil temperature, soil moisture, soil pH and soil organic matter.     

林龄、采伐方式对大叶相思萌芽更新的影响*

在海南省琼海县进行了不同林龄、不同采伐方式对大叶相思萌芽更新影响的研究，同时比较了保留不同萌条数量的萌芽林生长表现。结果表明：（１）林龄对伐桩萌芽率没有显著影响，但对伐桩存活率及萌条的径、高生长影响显著或极显著。林龄越大，萌芽更新效果越差；（２）皆伐和隔行采伐对大叶相思伐桩的萌芽率、萌条数量和存活率均无显著影响，但对萌条的径、高生长影响极显著。试验证明对大叶相思林分施以隔行采伐通过萌芽更新建立复层     

林龄、采伐方式对大叶相思萌芽更新的影响

在海南省琼海县进行了不同林龄、不同采伐方式对大叶相思萌芽更新影响的研究，同时比较了保留不同萌条数量的萌芽林生长表现，结果表明：（１）林龄对伐桩萌芽率没有显著影响，但对伐桩存活率及萌条的径、高生长影响显著或极显著。林龄越大，萌芽更新效果越差；（２）皆伐和隔行采伐对大叶相思伐桩的萌芽率、萌条数量和存活率均无显著影响，但对萌条的径、高生长影响极显著。试验证明对大叶相思林分施以隔行采伐通过萌芽更新建立复层林分是可行的；（３）保留不同数量萌条对萌芽林早期（１．５年生）的径、高生长有极显著影响，但对后期（４．５年生）的生长影响不显著。每棵植株伐桩保留４根萌条的萌芽林生物产量最高，更新效果最好。     

马尾松低效人工林土壤易氧化有机碳在不同改造措施下的分布特征

通过马尾松(Pinus massoniana)低效林的改造试验,研究了3种不同改造措施(皆林砍伐重造,补林种植间歇砍伐,纯林措施对照)对地层土壤易氧化有机碳含量的影响,结果表明,易采取相同的改造措施时,随着土层不断加深,不同土壤层的易氧化有机碳含量逐步降低,表现为0~20 cm土壤层>20~40 cm土壤层;同一土壤层下不同改造措施易氧化有机碳含量不同,表现为皆林砍伐重造<大林窗补植间伐<小林窗补植间伐<马尾松纯林。说明在改造初期,有机碳分解速率加快土壤易氧化有机碳的含量降低,并且改造面积越大,降低程度越大。上述改变差异在表层0~20 cm土壤中较为突出,在土层深度不断增大的过程中,其差别日益减小。     

Aboveground biomass of three conifers in the Qianyanzhou plantation, Jiangxi Province, China

Regressive models of the aboveground biomass for three conifers in subtropical China—slash pine (Pinus elliottii), Masson pine (P. massoniana) and Chinese fir (Cunninghamia lanceolata)—were established. Regression analysis of leaf biomass and total biomass of each branch against branch diameter (d), branch length (L), d ³ and d ² L was conducted with functions of linear, power and exponent. A power law equation with a single parameter (d) was proved to be better than the rest for Masson pine and Chinese fir, and a linear equation with parameter (d ³) is better for slash pine. The canopy biomass was derived by adopting the regression equations to all branches of each individual tree. These kinds of equations were also used to fit the relationship between total tree biomass, branch biomass, foliage biomass and tree diameter at breast height (D), tree height (H), D ³ and D ² H, respectively. D ² H was found to be the best parameter for estimating total biomass. However, for foliage biomass and branch biomass, both parameters and equation forms showed some differences among species. Correlations were highly significant (P<0.001) for foliage biomass, branch biomass and total biomass, among which the equation of the total biomass was the highest. With these equations, the aboveground biomass of Masson pine forest, slash pine forest and Chinese fir forest were estimated, in addition to the allocation of aboveground biomass. The above-ground biomass of Masson pine forest, slash pine forest and Chinese fir forest was 83.6, 72.1 and 59 t/hm² respectively, and the stem biomass was more than the foliage biomass and the branch biomass. The underground biomass of these three forests which estimated with others’ research were 10.44, 9.42 and 11.48 t/hm², and the amount of carbon-fixed were 47.94, 45.14 and 37.52 t/hm², respectively. __________ Translated from Chinese Journal of Applied Ecology, 2006, 17(8): 1382–1388 [译自: 应用生态学报]     

间伐对库区生态公益林养分流失的影响

以福建永安安砂库区生态公益林为研究对象,通过设置径流小区法,分别在坡度25°和32°的林地中,设计不间伐、间伐强度20%、40%、60%4种处理,研究不同间伐强度对安砂库区生态公益林养分流失的影响。结果表明:林地坡度25°情况下,在养分月流失量及流失总量上,间伐强度60%、40%均明显大于不间伐处理,而间伐强度20%与不间伐处理间差异并不明显,且流失量较少。林地坡度32°条件下,养分的月流失量及流失总量总体上随着间伐强度的加大而增加。此外,同一间伐强度下,养分流失总量随着坡度的增加而增加。可见,对库区生态公益林进行抚育间伐时,选择坡度较缓的林地进行低强度间伐(间伐强度20%)较为合理,能够在很好地发挥生态公益林的生态效益的同时获得一定的经济效益,进而实现库区生态公益林的可持续经营。