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1.
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
2.
Development of water oak stump sprouts under a partial overstory 总被引：2，自引：0，他引：2
A 28-year-old water oak (Quercus nigra L.) plantation was thinned from below to either 254 or 462 stems per hectare to determine the influence of a partial canopy on oak stump sprout development. Sprout clump survival, number of living sprouts in a clump, and height and DBH of the dominant sprout in a clump were measured in years 1–5 and 7 after harvest. By year 7, sprout clump survival under the heavily thinned canopy was 23% higher than under the lightly thinned canopy. Within-clump sprout mortality was not influenced by overstory thinning level, but by year 2 height and diameter increment were 15% and 22% greater, respectively, under the heavy overstory removal. Positive height and diameter growth of dominant sprouts continued under both canopy conditions through year 7, but early benefits of the heavy overstory removal on sprout growth diminished. Additional overstory removal or sprout clump thinning would be necessary to sustain sprout clump survival and sprout growth over extended periods. 相似文献
3.
The survival and development of Liaodong oak (Quercus liaotungensis Koidz) stump sprouts were studied for 6 years under leave-tree, as well as 60 and 75% crown closure uniform shelterwood in the Huanglong Mountains of China. Stump sprout survival rate, number of sprouts, and sprout height under the three partial harvests during the first year post-harvest did not differ. Six years post-harvest, 78.32% of the stumps had living sprouts. No variation in sprout survival was found among the treatments throughout the study period. The number of living sprouts per stump was 13.77 ± 0.50 in the first growing season after harvest, and dropped to 6.49 ± 0.22 after 6 years. This result indicated the occurrence of self-thinning within the sprout clumps. Moreover, the height of dominant sprout increased from 52.88 ± 1.62 cm (in the first year) to 132.82 ± 2.35 cm (in the sixth year) post-harvest. Sprout height in the leave-tree harvest type was higher than those in the two shelterwoods in the fifth and sixth years after logging. Annual height growth was approximately 8–96 cm during the first growing season, and then decreased at a rate of 1–44 cm per year in the following years. A negative relationship was found between sprout height and the number of sprouts per stump. This result indicated a trade-off between the number of sprouts and height growth. The number of sprouts per stump decreased by about 0.2 stem for each 1 m2/ha increased in residual basal area. Therefore, sprouting may play an important role in the restoration of the secondary forest after harvesting. 相似文献
4.
A study was established in the Missouri Ozarks to evaluate coppice regeneration of oak. Five years after a 32-year-old stand was clearcut and regenerated naturally through stump sprouts, the dominant sprout on each stump was identified based upon height. Treated plots were thinned to the single dominant sprout on each stump whereas control plots were not thinned. Twenty-five years later the largest 247, 371, 494, and 618 stems per ha were examined and height of the dominant sprout at age 5 was found to be strongly related to dbh at age 30 in both thinned and unthinned plots. However, in the thinned plots, the largest 494 stems per ha were on average 11%, 28%, and 58% greater, respectively, in height, dbh, and volume compared to similar dominant sprouts in unthinned plots. Logistic regression analysis was used to develop curves for the evaluation of potential gains from clump thinning. In this analysis, the average height of a stand at age 5 was used to estimate thinning gains at age 30. 相似文献
5.
The effects of thinning were investigated on naturally regeneratedFraxinus rhynchophylla Hance (Korean ash) grown in the understoreyof a Larix kaempferi (Lamb.) Carr. plantation, established ona site that previously supported old growth hardwood forests.The regeneration characteristics were evaluated after thinningof the plantation (about 60 per cent of relative density wasremoved). In the naturally regenerated and mixed stands, Quercusmongolica Fisch. was the most abundant tree species in the overstorey,but the understorey of the thinned plantations was dominatedby F. rhynchophylla with six other minor tree species. Fraxinusrhynchophylla was regenerated by four propagation types includingnatural seedling, stump sprout, root sprout and layering. Beforethinning, the difference of average height growth for each regenerationtype was insignificant. One year after thinning, the stump sproutsshowed the fastest growth among the regeneration types. Heightgrowth of advance regeneration was slow in the year followingthinning but then increased rapidly surpassing the other regenerationtypes 5 years after thinning. Thinning had an effect on thecomposition of regenerated trees also by seedling, stump sprout,root sprout and layering in the understorey. Advance regenerationsoccupied the upper understorey at 5 years after thinning. Alarge number of stump sprouts emerged in the plots 1 year afterthinning, while at 5 years after thinning the occupation ofstump sprouts decreased. Root sprouts and layers faded away.Considering the early growth and the composition of understoreyF. rhynchophylla, its advance regeneration has a high potentialto develop into overstorey trees at this site. 相似文献
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8.
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
9.
Sprout contribution to natural regeneration of Rhododendron arboreum following the tree felling for fuel wood and other purposes was studied in two disturbed sites (Paipraw and Falockchar) of
Rhododendron forest in Arunachal Pradesh, northeast India. Cut stumps were categorized into seven girth and height classes to evaluate
the effect of stump girth and height on production of sprouts. Effect of stump girth on survival of sprouts was also investigated.
Results show that highest number of cut stumps is recorded in medium girth classes (50–80, 80–110, and 110–140 cm) in both
Paipraw and Falockchar stands. However, density of cut stumps is higher in Paipraw (1 210 stumps·ha−1) than Falockchar (1 154 stumps·ha−1). Nevertheless, a little higher percentage of sprouting is recorded in Falockchar (18%) than that of Paipraw (15%). Similarly,
maximum number of cut stumps is observed in the medium height classes (50–80, 80–110 and 110–140 cm) in both the sites. Cut
stumps with lower girths show greater ability of sprouting than that of larger girth classes. Significant correlations are
observed between stump girth and sprout number and between stump height and number of sprouts. Survival of sprouts also depends
on stump girth. Survival of sprout shows significant variations between different sampling times in both the sites. Though
overall sprout regeneration of R. arboreum is very poor, sprouts arising from lower girth classes survive well than those of higher girth classes. The findings of this
investigation signify that stump sprouting is not playing much role in the natural regeneration of R. arboreum though it has the ability to sprout. Sprout survival is not adequate to restore a stand where indiscriminate tree felling
is continued and the species may be considered as a poor coppicer. Therefore, regeneration through seeds and seedlings should
be preferred over regeneration through sprouting. 相似文献
10.
For establishment to be successful, planted oak must emerge above vegetative competition and browse level. A 3 year study
was established in 2000 in a cutover bottomland hardwood forest in west Alabama to examine the influences of seedling browse
protection and fertilizer use on growth of Nuttall oak (Quercus nuttallii Palm.) seedlings. The treatments included: control, 1.2 m tall wire tree shelter, and 1.2 m tall plastic tree shelter. Fertilizer
(20–10–5) was applied to one-half of all seedlings at planting. Competing vegetation was controlled around all seedlings with
mulch mats and herbicide. Fertilization did not affect height growth or successful establishment after 3 years. Four percent
of protected seedlings (plastic and wire tree shelters combined) were browsed compared to 95% of control seedlings. After
3 years, plastic tree shelters were the most effective treatment for promoting height growth and successful seedling establishment
of Nuttal oak seedlings (193 cm, 92.71% compared to 120 cm, 68.75% and 52 cm, 8.33% for wire tree shelter, and control seedlings,
respectively). Animal browse protection is deemed essential for successful seedling establishment in southern bottomland forests
where deer density is high (density estimated at 27 km−2 in vicinity of study area). 相似文献
11.
《Scandinavian Journal of Forest Research》2012,27(1-4):509-518
Altogether 1 080 two‐year‐old silver birch (Betula pendula Roth) were planted in groups of 36 plants at aspacing of 20 x 20 Cm in spring 1983 on a nursery field at lat. 60° 15 N and long. 16°00 E. In spring 1984 all plants were cut with 10 cm high stumps and light screens were arranged on the stump groups. Relative ¡rradiance (RI) 5, 10, 25, 50, 75 and 100% of full sunlight were used. After five growing seasons, all stumps exposed to 5 or 10% light intensity were dead, and 64–94% of stumps exposed to 25–100% RI were alive. 1.3–1.4 sprouts per living stump were living five years after cutting. The mean height of sprouts was highest on stumps exposed to 100% light. Also dry weights of leaves and sprouts, number of leaves per sprout, and leaf area were highest on stumps exposed to full sunlight. Stumps producting only one sprout five years after cutting have higher height and dry weight values than stumps with more sprouts. The biomass production per hectare and year for silver birch sprouts at a spacing of 0.2 m and with 90% survival was calculated as 5.4 tonnes. The biomass of leaves was 8.1 tonnes/ha/year five years after cutting. 相似文献
12.
Influence of thinning time and density on sprout development, biomass production and energy stocks of sawtooth oak stumps 总被引：1，自引：0，他引：1
Zhilong Liu Shengzuo Fang Dong LiuMukui Yu Luozhong Tang 《Forest Ecology and Management》2011,262(2):299-306
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
13.
对速生多用途树民占相思进行了不同伐桩高度（25cm,50cm,75cm和100cm)及不直径（4．1－8．0cm和8．1－12．0cm)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高度的增加而增加，随直径的增大而减少，萌条直径，长度及直萌条（可望生长成材之萌条）总断面积随伐桩的高低和大小而增减，伐桩最低的萌芽率比以往的结果高4倍以上，以短轮伐期经营的马占相思人工林，采用50－75cm伐桩高度萌芽更新效果好。 相似文献
15.
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
16.
We initiated a study on a bottomland site in the southern United States to examine the effects of Japanese honeysuckle (Lonicera japonica Thunberg) control and seedlings of two root classes on survival and growth of underplanted cherrybark oak (Quercus pagoda Raf.) seedlings. Three honeysuckle control treatments were assigned to nine 0.5-ha plots in a stand harvested to 30% residual stocking. Treatments included a spring 1997 herbicide application (Escort®, metsulfuron-methyl), a similar application in the late summer of 1997, and a control (no herbicide application). In 1998, half of each treatment plot was planted with seedlings having four or more first-order lateral roots > 1 mm in diameter, while the other half of each plot received seedlings with fewer than four lateral roots. Four years after treatment, the early season application reduced honeysuckle biomass 60% relative to the other treatments, but we did not observe a survival or growth response by underplanted seedlings. Three years after establishment, seedlings that initially had four or more lateral roots were 16% taller and 18% larger in root-collar diameter than seedlings in the other class, but these differences were primarily due to initial size differences maintained through the study period. Over all treatments, oak seedlings averaged 87% survival while showing a 300% increase in height and a 170% increase in root-collar diameter 3 years after planting. Our results suggest that partial stand harvesting followed by underplanting may be a viable approach for establishing cherrybark oak reproduction on bottomland sites of the southern United States. 相似文献
17.
The physiognomy of Caribbean dry forest is shorter, denser and contains a greater proportion of multi-stemmed trees than other neotropical dry forests. Our previous research, conducted after Hurricane Georges in 1998, has shown that dry forest trees sprout near the base following hurricane disturbance, even if the trees have not incurred structural damage. However, for these hurricane-induced sprouts to contribute to the physiognomy of the forest, they must grow and survive. We followed sprout dynamics and stem mortality on 1,407 stems from 1998, after Hurricane Georges, until 2005. The number of surviving sprouts and the proportion of sprouting stems decreased during the 7-year period, but the sprouting rate was still 3-fold higher and the proportion of sprouting stems 5-fold higher than before the hurricane. Mortality of non-sprouting stems (15.4%) was about the same as for sprouting stems (13.9%) after 7 years. The mean length of the dominant sprout surpassed 1.6 m by 2005, with over 13% of the dominant sprouts reaching subcanopy height. Sprout growth and survival varied among species. These results demonstrate that, despite some thinning, hurricane-induced sprouts survive and grow and that the unique physiognomic characteristic of Caribbean dry forests is related to hurricane disturbance. 相似文献
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19.
砂生槐(Sophora moorcroftiana)是西藏"一江两河"地区农牧民的传统薪柴。为了合理经营砂生槐薪炭林,2012年11月,选择西藏拉萨北山封育10年的砂生槐灌丛设置试验地,研究3种平茬高度(0 cm、10 cm、20 cm)对砂生槐萌蘖、萌枝生长及生物量的影响。结果表明:萌蘖数量从大到小的排序为20 cm平茬10 cm平茬0 cm平茬;单个萌枝的生长(长度、基径)0 cm平茬10 cm平茬20 cm平茬。生物量从大到小的排序为10 cm平茬0 cm平茬和20 cm平茬。经营砂生槐薪炭林,为了获得较多的薪柴,建议采用距地面10 cm平茬。 相似文献
20.
A small scale agroforestry study which was begun in 1952 was revisited in 1985 to evaluate the long-term influence of site
preparation and grazing on tree growth and survival in a Douglas-fir (Pseudotsuga menziesii)-white oak (Quercus garryana)-sheep silvopastoral system. In 1952–1953, two-year-old Douglas-fir seedlings were planted at the rate of 2500 trees/ha under
three levels of site preparation: (1) no treatment, (2) oak thinned by 50%, and (3) oak clearcut. From 1954 to 1960, yearling
ewes grazed one-half of each of the three thinning treatments for 3–4 weeks each spring. The conifers have been undisturbed
since grazing was discontinued in 1960. Survival of planted conifers averaged 64% in 1985 and did not vary among either site
preparation or grazing treatments. From 1964 to 1985, trees on the thinned and clearcut plantations grew an average of 1060
and 990 cm in height, respectively, compared to 900 cm on the unthinned plantation. Diameter at breast height (dbh) averaged
3.8 and 5.6 cm greater on thinned or clearcut plantations, respectively, than on the unthinned control by 1985 (p < 0.05).
Conifers on grazed plantations had increased height and dbh growth during the first 12 years of plantation life, averaging
63 cm taller (p < 0.10) and 0.7 cm greater in dbh (p < 0.05) than the ungrazed plots by 1964. By 1985 the difference in height
(122 cm) and dbh (1.0 cm) between grazed and ungrazed plantations was not statistically significant. These data suggest that
although site preparation can positively influence conifer growth, total clearfelling is no better than thinning oaks. Furthermore,
proper grazing can increase height and dbh growth of the conifers during and immediately after the grazing years. 相似文献