毛竹林冰雪灾害成因及复壮技术

通过对导致2022年春季漳平市毛竹林冰雪灾害加重的原因进行分析,提出了通过及时清理受灾竹株、科学留笋养竹、合理采伐竹林、适时做好土肥管理和营建竹阔混交林等技术,使受灾竹林恢复至灾前生产力水平,为漳平市冰雪灾害后毛竹林复壮提供技术支撑.     

毛竹冰冻雪灾后恢复技术

调查了广西毛竹(Phyllostachys heterocyclavar.pubescens)主要产区冰冻灾害的基本情况,发现毛竹受灾后表现出压弯、折断、破篾、倒伏、翻蔸等形态,灾害程度依次加重。针对不同程度的受灾竹林,提出了毛竹林灾后恢复技术措施,主要有及时清理翻蔸竹、适时砍伐折断竹、破篾竹、保留压弯竹;严禁采挖冬笋、春笋;加强出笋前后施肥;适度钩梢;清除病竹等。     

冰冻雪灾对黄山区毛竹林的损害及影响因子

研究安徽省黄山区2008年1月冰冻雪灾对毛竹林的损害及影响因子.结果表明:此次雪灾对毛竹林破坏严重,各类受损竹比例达45.8%,其中翻蔸竹13.9%,断裂竹9.4%,对竹林生态系统影响较大.从毛竹生物学影响因子看,年龄和胸径对受灾程度的影响不大;而从各林地状况因子与毛竹受灾程度的关系看,海拔、地形、坡向和立竹度对毛竹受损率影响显著,T检验P值分别为0.008,0.000,0.045和0.052,并呈现出不同的主要受损类型,经营状况和树种组成的影响程度不明显.     

高温干旱下毛竹林受灾状况和自恢复能力研究

2013年夏季,我国东南部地区发生了严重的高温干旱天气,毛竹林受灾严重。通过设置固定样地研究了高温干旱后毛竹林的受灾状况以及灾后竹林的自恢复能力。结果表明:在高温灾害发生以后,胸径较大的毛竹抵御灾害的能力高于胸径较小的毛竹;受灾毛竹地上部分生物量80%以上分布在竹秆中,因此竹枝和竹叶受损对毛竹地上生物量的影响不大;毛竹林受灾后的恢复能力在很大程度上取决于受灾当年新生竹的株数。因此,在毛竹林经营中应加强林地的水肥管理,培育大径竹材,同时应保持较高的立竹密度和较多的新生竹数量,以抵御旱灾并加快林分的灾后恢复。     

毛竹林持续高温干旱灾害特征及影响因素分析

为探讨持续高温干旱灾害天气对毛竹林生长的影响,为毛竹林抗灾减灾及灾后恢复提供参考,调查分析了毛竹林持续高温干旱灾害特征及立地条件、经营水平等对立竹受损程度的影响。结果表明:持续高温干旱天气使毛竹叶片灼伤、枯黄、失绿变白,严重的全株叶片脱落;竹秆脱水、皱缩、枯黄,中下部位出现黑斑,局部表皮灼伤。竹龄越小受损程度越严重,1度竹死亡率显著高于2度及2度以上竹。海拔高度、坡向、坡位、土壤厚度、立竹密度、经营水平等对毛竹林立竹受损程度均有较明显的影响,其中海拔较高毛竹林高于海拔较低毛竹林,阳坡毛竹林显著高于阴坡毛竹林,且上坡>中坡>下坡,土壤厚度<50 cm 毛竹林明显高于土壤厚度>100 cm毛竹林,立竹密度3 750 4 500株·hm^-2和2 250 3 000株·hm^-2毛竹林高于立竹密度3 000 3 750株·hm^-2毛竹林,集约经营毛竹林高于粗放经营毛竹林。典范对应分析(CCA)表明,持续高温干旱灾害对毛竹林的影响因子主要为土壤厚度、坡位,其次为海拔高度、坡向和立竹密度。     

竹腔(蔸)施肥对雪灾后毛竹林生长的影响

设置4种施肥方式:竹腔施毛竹增产剂BNP、竹蔸施尿素、竹腔施BNP+竹蔸施尿素、竹腔施植物生长调节剂GGR,不施肥为对照,试验研究了不同施肥方式对雪灾后毛竹林生长的影响。结果表明:毛竹竹腔(蔸)施肥,可以明显提高毛竹林立竹数和平均胸径,促进雪灾后毛竹林尽快恢复;连续施肥3年后,毛竹林立竹数和平均胸径分别较对照提高16.8%和5.6%。不同施肥方式比较,以竹腔施BNP+竹蔸施尿素效果最好,其次为竹腔施BNP和竹蔸施尿素,而竹腔施GGR则对毛竹胸径生长有明显的促进作用。这几种施肥方式均值得在生产中推广应用。     

江西安福林区毛竹林雨雪冰冻灾情调查分析

对江西安福毛竹林2008年发生大面积雨雪冰冻灾情的调查和分析.结果表明:毛竹受灾程度与海拔高、林分密度和立竹年龄等有显著相关,其受灾规律为海拔350 m和1 000 m的毛竹林受灾程度分别为51.8%和71.7%;壮龄竹和幼龄竹的受灾程度分别为29.7%和53%;林分密度为2 400～3 000株·hm-2的毛竹林受灾程度为32.5%,分别是立竹度为3 000株·hm-2以上和2 400株·hm-2以下的损失率48.3%和90.3%.此外,毛竹林受灾程度还受林分类型、不同坡度、不同坡向等影响,其表现为纯林大于混交林,陡坡大于缓坡,西北坡大于南坡,说明此次毛竹受灾程度是多因素综合作用的结果.     

不同林分结构对绵竹产量的影响研究

绵竹是四川优良的乡土竹种。本研究在绵竹主要分布区沐川、叙永设置了125个经营水平大体一致的样地开展不同林分结构(年龄结构、均匀度、整齐度和立竹度)对绵竹产量的影响研究。结果表明:绵竹林的年龄结构、整齐度和立竹度对竹材产量有显著影响,而均匀度对产量影响不显著。当绵竹林以1 a~2 a年生竹为主,整齐度为10,立竹度在10 000株·hm~(-2)时,绵竹竹材产量最高,是绵竹林最优林分结构。     

冰雪灾害对大关县4种竹林损害的调查研究

对云南省大关县4种竹林经2008年1月特大强降温冰雪天气过程后的受其冰雪灾害损害的情况进行了调查研究.结果表明:(1)慈竹林受损比水竹林、斑竹林和筇竹林严重;(2)随海拔高度的升高4种竹林的受损随之严重;(3)慈竹、斑竹和水竹3种竹林的受损率与其竹林立竹密度的大小呈正相关,而筇竹林的受损率则随其竹林立竹密度的增加而下降;(4)同一竹林胸径大的竹子比胸径小的竹子更容易受损害而折断和破裂.     

毛竹纸浆竹林均匀度及整齐度研究

笔者通过不同海拔高与纸浆毛竹林立竹均匀度和整齐度的关系研究,结果表明：纸浆毛竹林的立竹均匀度与整齐度均随海拔高度的增加而减小的变化趋势。竹林采取措施能提高竹林的均匀度与整齐度,其施肥样地的U值与E值分别是未施肥样地1．45与1．17倍。     

Snow disturbances in secondary Norway spruce forests in Central Europe: Regression modeling and its implications for forest management

Snow is an important ecological factor limiting vegetation distribution, growth, and regeneration, and the importance of snow in the latitudes of Central Europe is expected to increase in the future. We assessed snow damage to secondary spruce stands (not of native provenance therefore not adapted to local conditions) in a mountainous region of 14500 ha in Central Europe (Moravian-Silesian Beskids, Czech Republic). We used neural networks-based regression modeling to study the relationship between stand and environmental parameters and four types of snow damage (top tree, crown, and stem breakage, and uprooting) that occurred during heavy snowfalls in winter 2005/2006 and 2009. Almost 40000 trees were sampled in 345 plots after each of these two events.The results suggest that parameters that can be controlled by forest management (mainly stand density and taper) were not closely associated with spruce forest resistance to snow damage. Investigated snow damage types were primarily related to the developmental stage of the stand, as indicated by stand volume, age, height, and diameter. Damage in 2009, which was caused by shorter-lasting and lower snow loads than the damage in 2005/2006, was also associated with elevation and snow depth. The response of snow damage to all stand development-related variables was clearly unimodal.We infer that forest management can reduce snow damage to secondary spruce forests in Central Europe only to a limited extent, especially under heavy snow loads. This conclusion is supported by the heavy snows that have frequently fallen on forests in Central Europe in the past and the projected increase in winter precipitation in mid- and northern latitudes; thereby increasing snow damage to forest in the future. Therefore, managers of such spruce forests should not specifically consider forest resistance to snow damage but should apply general practices that maintain forest health and productivity.     

毛竹林立竹密度研究

在湘潭市选择一般经营水平的毛竹林,设置固定标准地50块,调查新竹产量和立竹笋前密度,建立新竹产量与立竹密度的二次抛物线函数模型,结果表明:抛物线拐点区域170～190株/667 m2为湘潭市一般经营水平下毛竹林的合理立竹密度。     

Snow damages on trees of an uneven age in mixed broadleaf forests:effects of topographical conditions and tree characteristics

Snow damage on natural stands is an important problem concerning mountainous forest management.In the present research,the frequency and intensity of heavy snow damage on natural stands and the relationship of damages with characteristics of trees,stand and topography were studied in mountainous forests of northern Iran.A systematic sampling design was applied to the study area(140 ha),with 122 circular plots.The grid dimension was100 m and each plot area was 1000 m^2.The four types of snow damage to trees include:crown damage(8.6%),stem breakage(5.4%),uprooting(3.2%),and bending(1.4%).The frequency of crown damage grew with an increase inthe diameter at breast height(DBH),while the frequency of stem breakage,uprooting and bending decreased with an increase the DBH.The frequency of crown damage,stem breakage,and total damages was related to tree species(p<0.01).Not all tree species were equally susceptible to snow damage.The amount of damage grew with increasing elevation and slope angle and decreased with increasing soil depth.Young trees(DBH<25 cm)were more susceptible to snow damage than other trees.Snow damage decreased by as the trees in the stand became more mixed in age.The susceptibility of trees to snow damage increased by height and slenderness coefficient.With adequate silvicultural operation,snow damage can be reduced to a minimum level in these natural forests.     

Model computations on the critical combination of snow loading and windspeed for snow damage of scots pine,Norway spruce and Birch sp. at stand edge

Model computations were made on the critical combination of snow loading and windspeed for snow damage of Scots pine (Pinus sylvestris L.), Norway spruce (Picea abies Karst.) and birch sp. (Betula sp.) at the newly formed stand edge with varying tree height and stem taper using the model developed by H. Peltola, S. Kellomäki and H. Väisänen (1996, HWIND: A Mechanistic Model for Wind and Snow Damage of Scotts Pine, Norway Spruce and Birch sp.) for the mechanism of wind and snow damage. In the computations, the total turning moment arising from the wind and snow load and from the bending of stem and crown was calculated along with the breaking stress of the stem and root anchorage. Windspeed variation within the crown and the vertical distribution of snow, stem and crown weight were also taken into account.According to computations, the critical combination of snow and wind loading for stem breakage and uprooting of trees was caused mainly by accumulation of snow on tree crowns, rather than by wind, which did, however, increase the risk of damage. The risk of damage increased along with stem taper decrease or tree height increase for all tree species studied. However, Scots pine and Norway spruce were found much more susceptible to snow damage than birch, which (being leafless) had much less crown area for snow attachment and wind loading.The trees most likely to suffer stem breakage were slightly tapering Scots pines and Norway spruces with tapers of 1:120 for varying tree heights of 12–20 m under short-term snow loading of 60 kg m⁻², i.e. they would have suffered stem breakage under windspeeds of less than 9 m s⁻¹ above the tree canopy top. Respectively, even Scots pine and Norway spruce with tapers of 1:100 were at risk of stem breakage through sustained snow loading of 60 kg m⁻². In addition, even snow loads of 20–40 kg m⁻² were found big enough to cause stem breakage of these trees with stem tapers of 1:120 during sustained snow loading. Correspondingly, similar pines and spruces with stem tapers of 1:120 were found to even more liable to be uprooted during conditions of unfrozen soil than of having their stem broken by short-term snow loading of 20–60 kg m⁻², i.e. less windspeed was needed to cause uprooting. However, pines and spruces with tapers of 1:80 were not at risk for stem breakage and uprooting. This was because snow would have more probably been dislodged from the tree crowns by windspeeds greater than 9 ms⁻¹ which are needed to worsen the damage. Nor would very slender birch without leaves have suffered stem breakage or uprooting under any circumstances with windspeeds of less than 9 ms⁻¹.     

冰冻雪压对杉木人工林近成熟林分危害调查

以受冰冻雪灾较为严莺的江西省大岗山林区杉木近成熟林分为研究对象,探讨杉木林分结构和立地条件与杉木受损类型及灾害发生程度的关系,得到几点主要结论:1)冰冻雪压造成大岗山林区杉木受害株数比例达66.84%,受灾相当严重,杉木林分受害类型可分为弯梢、断梢、斜干、断干、倒地及翻蔸等6种,其中断干和断梢为最主要的2种受害类型.2)杉木林分结构对冰冻雪压危害具有明显的调节作用,灾害主要发生于径阶相对较小的林木,林分内径阶越大的林木其受害程度明显越轻;林分密度与受害强度具极显著正相关,密度越高,林分受损株数愈多,且密度主要影响断干、翻蔸这2种不可逆的受损类型,合理的密度调控至关重要.3)杉木林分的立地条件与受害程度紧密相关,高海拔、高坡位、陡坡处的林分更易受到冰冻雪压的危害,较高的立地指数有利于杉木在遭受冰冻雪压灾害时减轻损失.     

毛竹林丰产年龄结构模型与应用研究

从南岭山脉以南的各毛竹产区中收集１３３０块高产林标准地,分别调查各度竹株数、胸径等测树因子与林分、环境因子,以用材林的竹秆产量,笋用林的笋产量为因变量,建立了产量模型：材用林Ｙ１＝－６２６９５．２４５＋６．５４１３Ｎ＋７０１２．５１９５Ｄ＋８．４５４８Ｘ１＋１１．０８７０Ｘ２＋１４．１５２０Ｘ３＋８．９９６９Ｘ４＋１４．５１５６Ｘ５笋用林Ｙ２＝６９７．５５６９＋０．２０５２Ｎ＋１．８５１４Ｄ－０．６４１４Ｘ１＋１．２４９３Ｘ２＋０．７６３６Ｘ３＋０．３７９０Ｘ４－０．８８３３Ｘ５（Ｒ１＝０．９８,Ｒ２＝０．９６）并结合生产要求,提出约束条件八组。应用该模型研究毛竹林最优化年龄结构,可以得到不同竹林质量、立竹量、立地条件、经营水平下最适宜年龄结构。能显著地提高林分的竹材和笋产量。     

闽南毛竹林合理经营密度的研究

在闽南毛竹分布区的毛竹林分中建立标准地２４７块，利用柯尔莫哥洛夫的正态分布检验法。结合半峰宽理论，分析计算了闽南毛竹林的合理经营密度为１２００株￣１６５０朱／ｈｍ＾２，为闽南毛竹林持续经营提供了理论依据。     

冰雪灾害影响与原因对策浅析——以浙江竹林为例

浙江省竹类资源丰富,竹产业发达,是全国重点产竹省。2008年初特大雨雪冰冻灾害致使该省竹林遭受重创,受灾面积52万hm~2,占竹林总面积的66.4%;直接经济损失36亿元,占林业总损失的37.7%。在介绍南方雨雪冰冻灾害成因的基础上,首先评估了竹林受灾、民生问题、生态功能、次生灾害等4方面的灾害影响;其次,从海拔、混交林和纯林、年龄结构、毛竹钩梢、林地垦抚和使用除草剂、坡度和生长位置等方面分析了竹林受灾原因;最后提出了6项灾害预防对策。