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1.
For reasons of aesthetics, sheltering, biodiversity, and children’s need of playgrounds, selective coppicing could be a useful and effective silvicultural method in urban areas. A randomised block experiment was carried out in three broad-leaved coppices situated within the fenced area of Arlanda Airport to compare a selective coppice regime (SCR), where all trees above a certain height limit were cut, with a traditional coppice regime, where all trees were felled. The effects of the treatments of the dominating tree species European aspen (Populus tremula L.) and birch (Betula pendula Roth and B. pubescens Ehrh.) were studied. During three growing seasons after performed treatment, the proportion of sprouting stools and root shooting of European aspen were reduced in SCR. Birch stools had fewer sprouts stool−1, and sprouts of both birch and European aspen tended to be shorter in SCR. There was a tendency that the sprout mortality was lower in SCR for both birch and European aspen. Residual stands of SCR consisted of proportionally less birch, and more rowan, bird cherry, oak and other species. Coppicing with single tree selection from above suppressed light demanding tree species and promoted the more shade-tolerant species compared to traditional coppicing.  相似文献   

2.
With an increasing demand of sustainable raw materials for bioenergy use, coppicing as management approach to increase the biomass production of forests is becoming of greater importance. This study describes the parameterization of biomass equations for six tree species traditionally used in coppices forests, namely sycamore maple (Acer pseudoplatanus L.), field maple (Acer campestre L.), European ash (Fraxinus excelsior L.), European hornbeam (Carpinus betulus L.), downy birch (Betula pubescens Ehrh.), and common hazel (Corylus avellana L.) growing in coppice-with-standard systems in Lower Saxony, Germany. The parameterization was based on measurements of over 950 trees sampled from two forest sites. The sampled trees were felled and separated into three biomass compartments (stem, coarse branches, and fine brushwood) and weighed on site. The dry weight of sub samples from each compartment was measured. Equations were derived for total aboveground biomass, stem biomass, and crown biomass using regression analyses. We either used diameter at breast height as single independent explanatory variable or in combination with tree height. Biomass production of stump sprouts and generatively grown stems was compared for ash and sycamore maple. In the same age classes, it was found that ash stump sprouts had a slightly higher production than seed-grown stems. For sycamore maple, no difference was detected.  相似文献   

3.
Viability of thinning sessile oak stands by girdling   总被引:1,自引:0,他引:1  
Reque  Jose A.; Bravo  Felipe 《Forestry》2007,80(2):193-199
The effects of girdling were analysed in a sessile oak (Quercuspetraea Matts. Leibl.) forest with an 80-year-old coppice withstandard structure in northern Spain. The study evaluated theviability of girdling as an alternative to felling trees duringcrown thinning. Eighty-four direct competitors of selected futurecrop trees were girdled by double notching and peeling. Threeyears after girdling, 100 per cent of the treated trees haddied. Approximately half of the girdled trees did not resprout.The occurrence of basal sprouting was very low, and more than35 per cent of the sprouts had very low vigour. No correlationwas found between sprouting and the diameter of the girdledtrees or the distance to their nearest neighbour. A negativerelationship between the diameter of the girdled tree and thestage of decline was recognized. Girdling is an economic alternativeto non-commercial thinning in oak stands and can be seen asan effective structural enrichment treatment.  相似文献   

4.
A major impediment to the sustainable management of tropical dry forests in Bolivia is the scarcity of natural regeneration of commercial timber tree species. Where regeneration is present, true seedlings of many species are outnumbered by vegetative sprouts from roots, broken stems, and the stumps of felled trees. This study evaluates the importance of resprouts promoted by logging operations for the regeneration of commercially important canopy tree species. The objectives of the study were: (1) to characterize stump and root sprouting behaviors of canopy tree species harvested for timber; (2) to quantify the effect of logging on relative abundances and growth rates of stump sprouts, root sprouts, and true seedlings; (3) to relate the species-specific probabilities of stump sprouting to stump diameter and stump height; and (4) to explore how sprouting varies with the ecological requirements of canopy tree species. The study was carried out 1–5 years after logging of a privately owned land in a Bolivian tropical dry forest. Twenty-seven of the 31 species monitored resprouted at least occasionally, among which Centrolobium microchaete (Leguminosae-Fabaceae) and Zeyheria tuberculosa (Bignoniaceae) were the most frequent stump sprouters, and Acosmium cardenasii (Leguminosae-Fabaceae) and C. microchaete were the most frequent root sprouters. In all species the number of sprouts declined with increasing stump diameter and stump height. The probability of stump resprouting differed among species but did not vary consistently with stump diameter, except in Z. tuberculosa in which it declined. Approximately 45% of juveniles <2 m tall of canopy tree species originated from root or stem sprouts. Light-demanding species tended to regenerate more from seeds and root sprouts than from stumps. Seedling densities were higher in microsites opened by logging, while root and stem sprouts were equally common across microsites. Given their abundance and the fact that root and stem sprouts at least initially grew faster than true seedlings, we conclude that vegetative regeneration in this tropical dry forest is an important mode of post-logging regeneration especially for species that regenerate poorly from seed. Resprout management should be considered as a potentially effective strategy for the procurement of regeneration following logging, especially for species that do not readily recruit from seed.  相似文献   

5.
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  相似文献   

6.
Abstract

On the Laurel Hill, anecdotal accounts reported coppice regeneration of oaks to be limited. Possible causes of poor sprouting success were large stump size, deer browsing, season of cutting and poor tree vigor. Our study site had been partially cut three years before this study to salvage some northern red oak (Quercus rubra L.) which had died. We attempted to increase Q. rubra vigor, as measured by increasing basal area growth, with soil amendments of 6,600 kg/h dolo-mitic lime, 110 kg/h K2O equivalents and 220 kg/h P2O5 equivalents while accounting for other growth variables. The objective was to improve overall Q. rubra sprouting success by increasing vigor prior to harvest. The soil amendments increased soil available calcium (Ca), magnesium (Mg), potassium (K) and phosphorus (P) and reduced available aluminum (Al). Foliar concentrations of Ca, Mg and K were increased. Basal area increment of treated Q. rubra trees increased by 10 percent and terminal elongation increased by nearly 100 percent. Two years after treatment, the trees were cut during the dormant season and all stumps were protected from deer browsing. After two years, 80 percent of the stumps had sprouted. No effect of lime and fertilizer on the sprouts was found.  相似文献   

7.
The miombo woodland is one of the most extensive woodlands in Africa, supporting livelihoods based on biomass fuel for millions of rural people. However, there are growing concerns about the sustainability of harvesting for biomass fuel(mainly charcoal). Thus, the aim of this study was to examine whether regeneration by coppice is a viable option for sustainably managing miombo woodlands for biomass fuel production. We tested the hypotheses that(1) species, stump diameter, stump height and time since cutting significantly affect the number of sprouts per cut stump(coppice density) and mean sprout height(shoot vigour) and(2) higher coppice density reduces shoot vigour due to competition among coppice shoots in a given stump. In an inventory in areas that were harvested for charcoal production by the local people, 369 stumps of 11 species were recorded with mean coppice stumps ranged from 6 to 84. The mean coppice density ranged from 5 to 8 shoots per stump while the mean height of coppice shoots ranged from 46 to 118 cm with marked interspecific variations. Stump size was significantly and positively correlated with coppice density for some of the species, but not with shoot vigour for the majority of the species. However, shoot vigour was significantly positively correlated to time since cutting of trees for nearly half of the species. Coppice density had a significant negative correlation with shoot vigour for two species, and a positive correlation for one species. In conclusion, the results provide evidence about the importance of coppice management as a win–win strategy for sustaining charcoal-based rural livelihoods and recovering the miombo woodland ecosystem.  相似文献   

8.
The aims of this study were to analyze the sprouting characteristics of Quercus pubescens and Q. frainetto trees after a wildfire and to recommend the appropriate silvicultural treatments in order to achieve dense sprout origin regeneration. This study was carried out in the area that was burned in a wildfire in northeastern Greece. Three years later, 140 Q. pubescens trees and 140 Q. frainetto trees were selected. Seventy trees for each species were individuals that were cut after the fire and were in the form of stumps, while 70 trees were intact top-killed trees, as a result of fire. In each stump and intact tree that was selected, various parameters were measured or counted: the diameter at the level of ground, the number of the developed sprouts (if any) and the height as well as the basal diameter of the tallest sprout, etc. Both species have similar sprouting behavior after a wildfire. Mother tree dimensions positively influenced the number of sprouts and the growth of the tallest sprout per individual. The mean height of the tallest sprout per stump, after three growing seasons from the forest fire, is high in both species (2.08 m for Q. pupescens and 2.29 m for Q. frainetto). Cut stumps had more sprouts than intact trees in both species. Forest practice, in order to maximize the sprouting of Q. pubescens and Q. frainetto trees after a forest fire, should cut the burned trees before the next growing season.  相似文献   

9.
文章以结构调控初期的城镇景观林为对象,调查测定间伐第1年主要树种的伐桩萌芽情况、萌枝数量、高度以及群落垂直结构,分析树种的萌枝能力及其群落的结构变化。结果表明,各树种的萌枝能力均较强,不同树种间存在极显著差异(F=129.5,P < 0.001),呈现"常绿树种产生数量多、植株矮小的萌枝,落叶树种产生数量较少、植株高大的萌枝"的格局。砍伐降低了林分密度,为冠层受压树种释放空间;同时,伐桩萌枝以其生长优越性快速恢复,占据高度3 m以下的空间,丰富了群落的垂直结构。因此,城镇景观林结构调控时,可通过砍伐并适当保留伐桩萌枝达到既控制林分密度又促进群落分层、维持群落和景观稳定性的作用。    相似文献   

10.
林龄、采伐方式对大叶相思萌芽更新的影响   总被引:1,自引:0,他引:1       下载免费PDF全文
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。  相似文献   

11.
东北东部林区次生林主要阔叶树种的萌芽更新规律   总被引:2,自引:1,他引:2  
对固定样地调查,采用伐桩的径、高度、萌芽的数量、萌芽的生长情况等指标,分析东北东部林区主要阔叶树种的伐桩萌芽更新规律。结果表明:在一定的伐桩径范围内,伐桩萌生枝数随着伐桩径的增大而增多;增长到一定程度后随着伐桩径的增大而减少;得出不同树种萌芽能力较强的年龄范围的伐桩径级。对于不同阔叶树种,伐桩高与当年生萌生枝数量的关系存在着不同的变化规律,研究地点具有产生萌芽能力的阔叶树种可划为3种类型:对数型、直线型、指数型,阔叶树的萌生枝高生长与伐桩径和伐桩高无明显关系。第2年伐桩萌生枝的数量与伐桩径的关系在总体趋势上与第1年基本相同,同时次年仍有新的萌生枝产生,但数量很少。与第1年不同之处在于萌生枝开始死亡,一方面,伐桩产生的萌生枝越多,死亡的数量也增大;另一方面,第2年的伐桩存活率在不同种类树种间差别较大:水曲柳高达96·2%,槭树为23·3%,榆树类为21·8%。所探讨的树种在研究区域内都有“萌代主”的能力,并且不同树种以及同一树种不同年龄,“萌代主”的能力和单个伐桩保存的萌生大树的数量不同。  相似文献   

12.
Stump sprouts are an important form of regeneration for a number of species in the southern Appalachians, especially the oaks (Quercus spp.). Alternative regeneration systems to clearcutting such as shelterwood and leave-tree systems are being implemented in many hardwood stands in the Appalachians. However, the effects of these alternative silvicultural systems on stump sprouts are not known. Therefore, we evaluated the impact of three silvicultural systems: a clearcut, leave-tree, and shelterwood on stump sprouting. These treatments were implemented in seven stands in Virginia and West Virginia in the Appalachian Plateau (AP) and Ridge and Valley (RV) physiographic provinces. The stands were even-aged oak dominated Appalachian hardwood stands with ages ranging from 62 to 100 years.  相似文献   

13.
The high potential values of sawtooth oak (Quercus acutissima) in fuelwood or bioenergy are recognized. Sprouting ability, sprout growth, biomass production and energy stocks in coppiced plantations of sawtooth oak were evaluated at the Hongya Mountain Forest Farm in Anhui Province, China. Experimental treatments applied in a split-plot design included three sprout thinning times and four sprout numbers reserved on each stump (1 sprout, 2 sprouts, 4 sprouts stump−1 and check). Sprout growth and biomass production per stump were significantly affected by the treatments and a significant positive relationship between stump basal diameter and sprout numbers produced was observed. After the third growing season, the highest total sprout biomass per stump was achieved in the treatment with thinning excess sprouts at the end of first growing season (December, 2007) and reserving 4 dominant sprouts per stump (T12S4, reaching 8.67 kg stump−1), while the lowest was found in the treatment with thinning the sprouts in August of the first growing season and reserving 1 dominant sprout per stump (T8S1, only 3.40 kg stump−1). Different treatments also influenced gross calorific values (GCV) of the components sampled from 3-year-old sprouts and the mean GCV of stem wood on an oven-dry weight basis was within the range of 18.45 ± 0.15 and 18.83 ± 0.12 kJ g−1. Similar to the sprout biomass production, the greatest total and stem energy stocks per stump were observed in T12S4 treatment, achieving 161.6 and 110.5 MJ stump−1, respectively. Based on the results from this study, thinning excess sprouts to reserve 4 sprouts per stump as early as age 1 could be proposed for the management of sawtooth oak coppice with cutting cycle of 3-5 years and stand density of 5000-6000 stump ha−1.  相似文献   

14.
Tree species composition of Central European alluvial hardwood forests has changed with the arrival of flood-intolerant and mesic species. Within this group of tree species, a dominant role is played by field maple (Acer campestre) and European hornbeam (Carpinus betulus). This study was performed in the Lanzhot natural forests at the confluence of the Morava and the Dyje Rivers, which are considered to be one of the most natural alluvial hardwood forests in Central Europe and where the absence of the direct influence by humans for 75 years has allowed spontaneous development. Our basic research questions were as follows: (1) does the mutual proportion and structure of field maple and hornbeam populations change along an elevation gradient of 4 m in an alluvial forest and (2) does the tree spatial pattern of field maple and hornbeam change along this gradient? The study found significant differences in the development of hornbeam and field maple populations with increasing elevation in an alluvial hardwood forest. While the strength of the hornbeam population clearly increases with increasing elevation, the field maple population does not. Compared to hornbeam, field maple is closer to the r-strategy side of the K-r continuum on alluvial sites. Our study reveals that field maple and hornbeam are mainly distributed in clusters on alluvial sites. Both species are concentrated at places with lower flooding intensity, i.e. to higher elevation sites. The study shows that tree spatial patterns could change dynamically along a short elevation gradient in alluvial hardwood forest.  相似文献   

15.
This study explores the sprouting characteristics of an evergreen broad-leaved forest after clear-cutting based on a survey of 1,893 stumps of 62 tree species in Okinawa, Japan. The sprouting capabilities of the stumps varied among tree species. The stumps of 60 species could produce sprouts, while those of the other two species could not. In 10 of the sprouting species, the mean sprout-stem number was higher than 4.0 stems per stump; nine sprouting species showed low sprouting capabilities. Additionally, Castanopsis sieboldii and Schima wallichii, the dominant species, exhibited high sprouting capabilities. Further, the sprouting capabilities varied with stump diameter at breast height (DBH). Stumps with a larger DBH tended to have a higher mean number of sprout stems per stump, higher DBH, and higher tree height than the smaller stumps. The forest stands regenerated by sprouting might recover into a tree community similar to that before clear-cutting.  相似文献   

16.
不同直径伐桩对赤桉萌芽更新影响的初步研究   总被引:4,自引:0,他引:4  
对速生树种赤桉进行了不同直径伐桩(2.1~6cm)萌芽更新影响的研究,结果表明:伐桩的萌芽率及平均萌条数随伐桩直径的增大而增大,萌条直径、高度随伐桩直径变化不大.  相似文献   

17.
辽东栎伐桩萌苗的发育规律   总被引:4,自引:0,他引:4  
通过对黄土高原黄龙山林区辽东栎林固定样地连续6年的调查,研究间伐强度分别为13.4%(弱度间伐)和30.0%(强度间伐)的辽东栎伐桩萌苗的存活与生长规律.结果表明:1)间伐第1年,辽东栎伐桩均有萌生枝发生,每桩萌生枝数量和萌生枝高度在不同强度间无显著差异;2)萌生枝数量受伐桩高度和直径的影响,当伐桩高度较低时,萌生枝数量随伐桩高度的增加而增加,超过20cm后随之减少,呈三次抛物线关系;伐桩萌生枝数量随着伐桩直径增加呈现先增加后减少的趋势,直径30~50cm的伐桩萌生枝数量最多;3)伐桩萌生枝数量与最长萌生枝高度呈显著线性负相关,存在“萌生枝数量——高度权衡”现象;4)间伐第6年,伐桩的存活率为97.01%,强度间伐区萌生枝高度显著高于弱度间伐区;5)调查期间,辽东栎伐桩萌生枝数量逐年下降,伐桩产生的萌生枝数量越多,后期萌生枝死亡的数量也越多,表明伐桩能够自我稀疏,存在“萌代主”现象.在黄土高原地区,辽东栎伐桩萌芽潜力很大,应合理利用;间伐时伐桩高度应尽量低于20cm;伐桩直径在30~50cm更有利于其无性更新;间伐后伐桩应及时除蘖定株,促进萌生枝生长;间伐强度30.0%(强度间伐)更有利于辽东栎伐桩萌生枝的生长.  相似文献   

18.
山西灵空山林区辽东栎萌芽更新规律研究   总被引:7,自引:0,他引:7  
以灵空山林区典型辽东栎皆伐迹地为研究区,调查了辽东栎伐桩径、高以及萌枝的数量、高度、基径等指标,分析了辽东栎萌芽更新规律。结果表明,在一定范围内,萌芽数量随着伐桩径的增大呈现先增多后减少的规律;而伐桩高与萌芽数量呈现弱相关,萌芽数量大体随着伐桩高的增大而增多,随即产生急剧下降的趋势。但萌枝的平均高、平均基径却不随伐桩径、高的变化而变化。在伐桩径、高的双因素方差分析中发现,对于辽东栎伐桩内萌芽数量而言,伐桩径与伐桩高具有显著的交互作用,而且伐桩高因素(5~20cm与21~40cm范围)具显著差异。  相似文献   

19.
桉树萌芽林留萌株数对伐期林分结构与材积的影响   总被引:1,自引:0,他引:1  
萌芽林采用随机区组设计,分别留萌1、1.5、2、3株·桩-1,结果表明:在萌芽林6年生时,平均胸径与树高随留萌株数增加而减少,平均胸径变异系数则增加;保存率与留萌株数的关系主要受到台风影响;不同留萌株数的树皮厚度与径级﹑生长量有关;留萌株数对桉树的树高与胸径影响不大;就单位总材积而言,留萌3株·桩-1的林分比1株·桩-1的高50%,2株·桩-1的比1株·桩-1的高10%.  相似文献   

20.
This study focuses on two rarely studied aspects of oak decline: relations with site characteristics and effects on tree growth. The study was carried out in a 5.5 ha stand in Hungary which is strongly affected by oak decline. The nearly pure sessile oak (Quercus petraea) stand of mostly coppice origin was 90 years old at the beginning of the study. Within-stand site heterogeneity was described by the herbaceous vegetation. Four ecological site types were distinguished by the species composition of herbs, and characterized by the ecological indicator values of the species. Tree growth between 1987 and 1993 was measured, and tree vigour was estimated from visual characteristics five times between 1987 and 1993. Potential volume increment of declining trees was estimated with the growth rates of healthy trees of the same size. Volume increment loss caused by oak decline was also assessed. Significant positive relationships were found between tree vigour and tree size and between tree vigour and tree growth. The growth of seriously declining trees dropped to almost one-half of that of healthy ones. Growth reduction of living trees at the stand level amounted to 5.4%, whereas growth reduction of all trees, including those that died during the observation period, amounted to 19.9% of the potential growth. Tree size and growth were greater on better sites. A strong relationship was also found between tree vigour and site type, but sessile oak was more susceptible to decline at better sites.  相似文献   

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