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1.
It was hypothesized that wood chips can serve as a mulch to improve the growth of young trees by facilitating the development of their root systems, inhibiting weed germination, and suppressing weed growth. The present study was carried out in Ghorogh Nursery, Golestan Northern Iran, in order to investigate the impact of wood chips application on root growth of oak (Quercus castaneifolia) seedlings and control of weed. A three centimeter wood chip layer was used on the soil surface as the mulch treatment with bare soil as the control. The number of new roots, the length of exciting roots and the density of weeds were measured after 5 and 12 weeks. Results showed that wood chip application had significant positive effect on the length of excising roots after 5 and 12 weeks compared with control seedlings. Also, weeds were reduced to near zero levels in treated plot. Our findings suggested that wood chip layer on the soil surface in the nursery can conserve soil moisture and prevent nutrient leaching from the rooting zone as well as diminish weed growth which consequently lead to production of high quality seedling. 相似文献
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《Scandinavian Journal of Forest Research》2012,27(1-4):160-168
The effects on seedling survival and growth of a new scarification method, inverting, were evaluated over 10‐yrs after planting lodgepole pine and Norway spruce on a 2‐yr‐oId clear‐cut in northern Sweden. Inverting, which provides planting spots containing humus turves covered in loose mineral soil without making mounds or ridges, was compared with ploughing, mounding, disc trenching, and no scarification. Subplots with high or low planting positions were used to assess small‐scale topographical effects. For both species, the treatment ranking according to stem volume production after 10‐yrs was inverting > ploughing ≥ mounding = disc trenching > no scarification. Inverting improved seedling height growth by approximately 35% compared with mounding or disc trenching and by more than 100% compared with no scarification. High survival rates were also found following inverting, but only the no‐scarification treatment resulted in a statistically significant reduction in survival rates (ca. 25%) for both species. Further development of the inverting technique might give environmental advantages compared with conventional mechanical site preparation. 相似文献
3.
Compared with conventional planting, direct seeding of Quercus spp. is a method that can reduce the costs of reforestation considerably. However, interference from natural vegetation and predation on acorns contribute to regeneration failures. Mechanical site preparation has the potential to reduce both these problems. To study the influence of sowing date and of different mechanical site preparation treatments on early seedling growth, an experiment was carried out in storm-felled areas, formerly Norway spruce forests, in southern Sweden from May 2006 to September 2008. Five treatments were applied and acorns were planted in May and July 2006. The treatments were: disc trenching, patch scarification, topsoil removal, mounding and an undisturbed control. A delay of less than two months in seeding resulted in the equivalent of one year's growth reduction with respect to oak seedling's height and biomass. This could be explained by delayed emergence of seedlings, and by the dry conditions during summer seeding. The seedlings only exhibited a weak positive biomass growth response following disc trenching, patch scarification and top soil removal. In the latter case this might be explained by increased soil compaction and extensive removal of the humus layer. Site preparation by mounding resulted in good vegetation control, an increased biomass growth response and deeper seedling roots. In this treatment, we found high relative light levels near seedlings, reduced soil moisture and dry bulk density of the soil and higher soil temperatures. One or more of these environmental factors could have influenced the growth response. Whether this increased early growth rate persists throughout young stand development is, however, uncertain. 相似文献
4.
[目的]研究干旱处理中油茶叶片内源激素、果实生长的变化规律以及地表覆盖、土壤翻耕2种措施对缓解干旱胁迫的效果。[方法]以6年生长林4#油茶为试验材料,设置自然状况、干旱胁迫、地表覆盖及土壤翻耕4个处理,采用酶联免疫吸附分析法(ELISA)测定油茶叶片内源激素,并分析果实的生长状况。[结果]研究表明:(1)干旱胁迫开始两周后,即当土壤含水率低于24.0%~26.8%,油茶叶片内源激素开始启动对干旱的响应机制。(2)干旱胁迫使油茶叶片IAA含量下降,ABA含量上升,GA含量先上升后下降,ZR含量下降并维持在较低水平,ZR/IAA值下降;地表覆盖及土壤翻耕可以有效缓解干旱对叶片IAA、GA、ZR含量的影响,而对叶片ABA含量、ZR/IAA的影响不显著;油茶通过内源激素含量的变化来应对干旱胁迫的影响。(3)干旱胁迫使油茶果实横径减小,果实纵径出现负增长,而地表覆盖及土壤翻耕相对于干旱胁迫使得果实横径生长量分别增加了73.20%、75.58%,可以有效缓解干旱胁迫对油茶果实纵径生长的影响。[结论]生产上通过地表覆盖及土壤翻耕可以有效缓解干旱对油茶果实生长的影响,地表覆盖技术措施可进一步推广应用。 相似文献
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《Scandinavian Journal of Forest Research》2012,27(2):131-138
The effects of soil scarification (mounding), slash removal and clear-cut age on the natural regeneration in clear-cuts was evaluated using data from four sites in southern Sweden. The treatments were carried out during a good seed and establishment year for birch ( Betula pubescens Ehrh. and B. pendula Roth). Scarification had the strongest positive effect on the density of naturally regenerated seedlings, especially in birch, but also in pine ( Pinus sylvestris L.) and spruce [ Picea abies (L.) Karst]. Slash removal had a positive effect on birch density. No statistically significant effect of clear-cut age was found. In addition, no statistically significant interactions between clear-cut age and scarification or slash removal were found. The ingrowth of field vegetation was the fastest in areas that were not scarified, less rapid in areas scarified on old clear-cuts, and the slowest after scarification in fresh clear-cuts. In conclusion, it may be possible to control the density of birch during a good establishment year for birch. If birch is desired, the best combination of treatments is to remove the slash and scarify; otherwise, these treatments should be avoided. 相似文献
7.
The aim of this study was to quantify the effects of different soil scarification methods on tree growth. Soil scarification influenced stem volume and stem biomass yield of lodgepole pine (Pinus contorta Dougl. var. latifolia Engelm.) in a 17-year-old field trial in boreal Sweden. Soil scarification (disc trenching, mounding and ploughing) resulted in an average stem volume yield of 3.1 and 34.2 m3 ha–1 on the poor and intermediate sites, respectively, while corresponding values for no soil scarification were 0.9 and 16.7 m3 ha–1. In comparison to no scarification, ploughing increased volume yields by 500% on the poor site and by 200% on the intermediate sites. The ranking according to stem volume yield was ploughing > disc trenching = mounding no soil scarification. Averaged over the two sites, the mean annual increment of stem biomass was 219% and 145% higher (in d.w., 0.26 kg and 0.34 kg per sample tree) after ploughing compared with no soil scarification, for the average and dominant sample trees, respectively. Although not significant, the increased growth rate after soil scarification decreased the average stem basic wood density of the sample trees with 1.6% and 5.3%, at the poor and intermediate sites, respectively. In conclusion, soil scarification significantly increased the 17-year stem volume yield compared with no scarification. The results also indicate that the difference in stem biomass yield between ploughing and the other methods, especially no soil scarification, will increase even more in the near future. 相似文献
8.
《Scandinavian Journal of Forest Research》2012,27(5):356-363
Abstract Biomass, total nitrogen (N) and total carbon (C) stocks were determined in trees, roots, field vegetation and soil in plots given two different site preparation treatments, deep soil cultivation (DSC) approximately 50?cm deep and patch scarification (PS), at three locations in Sweden 10?years after treatment. One location was planted with Pinus contorta, one with Picea abies and one with a mixture of P. abies and Pinus sylvestris. No differences were found in total ecosystem (trees, roots, field vegetation and soil) C and N stocks between the DSC and PS plots. In the DSC plots the tree biomass, tree N and C contents and total biomass were higher than in the PS plots, but the opposite was found for stocks in field vegetation. Biomass and C stocks in the total vegetation (trees, roots and field vegetation) were higher in the DSC plots. However, vegetation N stocks did not differ between the soil treatments, probably because the combined amount of leaf tissue in the trees and field vegetation did not differ between them. The proportions of biomass allocated to roots, stems and needles did not differ between the two treatments. However, the rooting was deeper in DSC plots, possibly because nutrient availability was higher, and subsoil density lower, following DSC than following PS. 相似文献
9.
Incorporation of forest slash during stand establishment is proposed as a means of increasing soil carbon and nutrient stocks. If effective, the increased soil carbon and nutrient status may result in increased aboveground tree growth. Eight years after study installation, the impact of forest slash incorporation into the soil on soil carbon and nutrient stocks, foliar nutrients and loblolly pine growth are examined on mineral and organic sites on the North Carolina Lower Coastal Plain. Treatments include leaving forest slash on the surface and flat planting (control); V-shear and bedding (conventional), mulch forest slash followed by bedding (strip mulch) and mulch forest slash and till into the soil followed by bedding (strip mulch till). After eight years, mulching and/or tillage did not have a significant impact (p > 0.05) on soil bulk density or soil chemical properties (pH, cation exchange capacity, soil nutrients). Additionally, neither tree foliar nutrients nor stand volume were significantly impacted. However, significant effects were observed for soil phosphorus contents and stand volume between the control plots and the other treatment plots. For example, the mean stand volumes on the mineral site were 24.49 ± 1.28, 38.16 ± 2.90, 44.59 ± 3.07 and 46.96 ± 2.74 m3 ha−1 for the control, conventional, strip mulch and strip mulch till plots. These observations are more likely due to the effect of bedding rather than mulching or tillage of the forest slash. These results are consistent for the mineral and the organic sites. Considering the greater expense to install the mulch and tillage treatments, the lack of a treatment effect on soil carbon and nutrient stocks and tree growth does not justify these treatments on these sites. 相似文献
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《Scandinavian Journal of Forest Research》2012,27(4):308-317
Abstract The effects of fencing and site preparation on performance of birch (Betula pendula Roth), oak (Quercus robur L.), pine (Pinus sylvestris L.) and spruce [Picea abies (L.) Karst.] seedlings were studied over four growing seasons in southern Sweden. The experiment was composed of four browsing treatments, from which roe deer (Capreolus capreolus L.) were excluded for 0, 12, 24 or 42 months, and four soil treatments. Natural browsing was combined with artificial browsing (clipping). It was demonstrated that browsing by roe deer could be isolated from browsing by moose (Alces alces L.) by selective fencing. Except for birch, browsing had little effect on seedling survival. Browsing reduced height growth by more than 100% for oak and pine, and more than 60% of pine seedling developed multiple stems. Except for oak, site preparation increased seedling survival. Inverting site preparation, in combination with or without fertilization, produced positive growth responses in seedlings, whereas patch scarification did not. There was no interaction between browsing and soil treatments on seedling performance. It was concluded that long-term protection against browsing by roe deer is needed for oak and pine, whereas short-term fences might be used for birch, and that spruce is relatively unaffected by browsing. 相似文献
12.
《Scandinavian Journal of Forest Research》2012,27(8):754-761
Abstract Stump harvesting is one way of increasing the amount of bioenergy, but little is known about the consequences of tree-stump harvesting on the carbon balance in the forest. Therefore, soil-surface CO2 flux (soil respiration, R s) was determined two years after clear-cutting for common soil disturbances occurring after patch scarification, harrowing and stump harvest in southern Sweden. R s from intact soil was found to be of the same magnitude as emissions from areas of mixed humus, indicating only small effects of disturbance. Elevated mounds produced lower emissions than in the intact soil during the second year despite larger amounts of organic matter, probably due to low soil moisture. The lowest R s was found in soil surfaces with exposed mineral soil. The treatment effects on R s were estimated considering the actual area of different disturbances. During the first year, there was no difference in R s among the treatments, whereas in the second year the flux was 10% higher after harrowing and stump harvesting than after patch scarification, implying that the effects on CO2 flux after stump harvest were comparable to conventional harrowing. However, it is unclear whether this finding basically applies to regions where decomposition is limited by soil moisture during the summer. 相似文献
13.
The root segments selected from dominant trees ofPopulus davidiana Dode were taken as reproductive material and were buried in different depths to carry out the reproduction of root turion
sprout. The affecting factors of gemination rate, survival rate, and height growth for cutting wood of root sprout were comparatively
analyzed. The results showed that the best suitable substrate for burying root is pearlite, with a germination rate of 15.16%.
3–4-cm root segments has the highest rate of germination (12.4%). The mixture of sand and soil (2∶1) is the best cutting substrate,
with a survival rate of 81.3%, while as to height growth of cutting wood, the mixture of turfy and soil (1∶1) is the best.
The cutting woods selected from different positions of stem show difference in height growth. The cutting wood from top stem
is higher obviously than those from middle or low stem.
Biography: XING Ya-juan (1969-), female, assistant researcher in Forest Research Institute of Heilongjiang Province, Harbin 150040,
P. R. China.
Responsible editor: Song Funan 相似文献
14.
Arne Sæbø Inger Sundheim Fløistad Jan Netland Brynjar Skúlason Øyvind Meland Edvardsen 《New Forests》2009,38(2):143-156
Abies nordmanniana and Abies lasiocarpa, established for Christmas tree production in southwestern Norway (58°44′N, 5°38′E), were treated with different weed control
methods, including chemicals, use of black plastic mulch, grass or clover as ground cover, living mulch and mechanical hoeing.
Ground cover with black plastic mulching resulted in the best growth and quality in A. lasiocarpa; the least favourable treatment was when grasses were allowed to grow close to the trees. Unless measures were taken to remove
this competing vegetation, the ground cover grew over the trees, smothering 94% of them. A. nordmanniana plants grew to the same height on plots with no weed control as on plots with thorough weed eradication. Stem diameter decreased
on plots with ground vegetation compared to seedlings grown in the weed-free environment. The use of Trifolium repens as ground cover decreased height growth by 30% compared to thorough weed control. Both grasses and clover sown as living
mulch, damaged the trees more than did natural weed vegetation. 相似文献
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《Scandinavian Journal of Forest Research》2012,27(2):110-121
Seedling growth is often hampered on sites dominated by Kalmia angustifolia. In June 2000, a trial was established on a clear-cut site in Quebec, Canada, with a high cover of Kalmia and Vaccinium species. The objectives were to evaluate how soil scarification and fertilization at the time of planting influence early growth and establishment of black spruce [Picea mariana (Mill.) BSP] and jack pine (Pinus banksiana Lamb.) seedlings. During the first 2 years, scarification reduced Kalmia cover three-fold and doubled the distance from seedlings to the nearest Kalmia stem. Scarification did not increase soil-extractable NH4-N concentration, and reduced soil potassium, calcium and magnesium. Scarification had no effect on seedling water stress. Seedling growth improved and foliar nutrient concentrations were generally higher in scarified plots than in unscarified control plots. No differences were observed between single- and double-pass scarification for any variables except for ground-level stem diameter of seedlings, which was greater with double-pass scarification (12.1 vs 13.1 mm). Spot fertilization increased seedling growth and foliar nitrogen concentrations. Jack pine growth was greater than black spruce growth, an effect enhanced when seedlings were fertilized. 相似文献
16.
Zaizhi Zhou Kunnan Liang Daping Xu Yuchen Zhang Guihua Huang Huaming Ma 《New Forests》2012,43(2):231-243
Many teak plantations are established on acidic soils with low nutrient availability. There is also poor documentation of
nutrient budgets for teak, therefore, a pot experiment with optimal hybrid regression design (Roquemore R311A) was implemented
with calcium, boron and nitrogen treatments with teak seedlings (Tectona grandis L.f.) planted in acidic lateritic red soil substrate. Seedling growth, biomass production and root development, and soil
pH, and exchangeable Ca and Al concentration were measured. Plant height, root collar diameter, biomass of leaves, stems and
roots, root volume, taproot length, number of lateral roots of teak seedlings were significantly and positively correlated
with soil exchangeable Ca, pH and Ca/Al molar ratio, and negatively correlated with exchangeable Al. All growth traits were
significantly affected by calcium, nitrogen and their interaction, but B fertilizer and other interactions had insignificant
effects. To effectively cultivate teak seedlings in acidic soil substrates, 1.68 g kg−1 quicklime (CaO) and 0.65 g kg−1 urea was suggested to be added to neutralize soil acidity, and enhance soil exchangeable Ca content and Ca/Al molar ratio.
Urea should not be added without quicklime. 相似文献
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[目的]揭示4种不同类型行道树的生长规律及其对地下土壤结构、养分和水分供需关系的适应情况,探索适于上海市行道树的土壤结构和养分等管理模式,以改善上海市行道树生长状况。[方法]采用土壤填充颗粒粒径、结构土比例以及基质湿度3因素4水平的正交试验设计,研究4种行道树在不同栽植基质下地上部分表型生长和根系发育状况。[结果]结果表明:不同栽植基质对悬铃木苗高有显著影响,对4种行道树根系发育及根系生物量积累均起到极显著作用。处理3栽植基质的悬铃木苗高最高(4.42 m),较对照组均值显著高出11.90%。4种树种根系发育的最佳栽植基质各不相同,处理8栽植基质下香樟根系发育最为优越,其根系总长、根系表面积和根系体积分别为162 564.21 cm、42 370.89 cm~2和833.98 cm~3,均显著高于对照等其它处理。银杏除根系总长在处理4栽植基质下达到最大值(26 498.01 cm),其余根系指标均在处理7栽植基质下发育较好,显著优于对照等其它处理。处理2栽植基质下悬铃木根系总长、根系表面积、根系平均直径和根系体积均显著高于其它处理。广玉兰根系生长指标均在处理6栽植基质下达最大值。香樟、银杏、悬铃木和广玉兰根系生物量分别在处理8、处理7、处理2和处理6栽植基质下达到最大,其最大值分别为1 029.52 g、871.93 g、1 294.84 g和1 025.62 g,且分别显著高出对照组均值80.44%、67.08%、61.21%和81.36%。通过模糊函数隶属法初步筛选出适宜香樟、银杏、悬铃木和广玉兰种4种行道树生长的栽植基质分别为处理8(土壤粒径3 cm,结构土比例80%,土壤湿度50%)、处理7(土壤粒径3 cm,结构土比例60%,土壤湿度40%)、处理2(土壤粒径5 cm,结构土比例40%,土壤湿度60%)和处理6(土壤粒径3cm,结构土比例40%,土壤湿度80%)。[结论]香樟生长对栽植基质水肥条件较敏感,适宜生长于水分适中、养分含量高的基质中;银杏较适生长在土壤通气良好、养分中等的立地,且其对水分要求相对较低;悬铃木适宜于通气性良好,水分和养分条件较好的基质中;广玉兰生长对基质含水量需求较大。对4种行道树进行养护时应根据其生长需求特点尽可能进行土壤水肥等条件控制。 相似文献
18.
《Scandinavian Journal of Forest Research》2012,27(3):209-220
Abstract The effects of soil scarification on reindeer lichen cover and re-establishment, reindeer foraging and damage possibly caused by reindeer to planted Scots pine seedlings were studied during six growing periods in a field experiment established in a reindeer lichen site that was grazed by a herd of 500–600 reindeer each winter. Seedlings (at a density equivalent to 2000 ha?1) were planted in mounds with mineral soil on top, in tracks with exposed mineral soil, in tracks with mixed organic material and mineral soil and in intact lichen mat (control) with no soil disturbance. The disturbed area varied from 0 to 28%. After six growing periods, the reindeer lichen cover and volume were 10–20% lower in the scarified plots than in the control plots. There was no clear evidence that the reindeer avoided foraging even in plots with the highest levels of soil disturbance. However, the behaviour of the reindeer during winter grazing seemed to be affected by both coverage of reindeer lichen (positively) and the proportion of exposed mineral soil (negatively). Damage possibly caused by reindeer trampling affected 8.2% of the living seedlings each year and approximately 50% of these seedlings were subsequently infected by fungal diseases (compared with 20% of viable undamaged seedlings). Scarification treatments that exposed mineral soil mildly resulted in higher survival and growth rates than the other treatments, especially the control. 相似文献
19.
《Scandinavian Journal of Forest Research》2012,27(2):90-98
Abstract The re-establishment rates of reindeer lichen following conventional soil preparation by disc trenching and gentle soil preparation using HuMinMix apparatus were calculated from data acquired in surveys of 17 Pinus–lichen clear-cut stands in northern Sweden conducted 1–15 years after the treatments. The maximum lichen cover and biomass recorded in areas scarified by disc trenching were 29% and 24% of the lichen cover and biomass measured in adjacent intact lichen mats in the surveyed stands after 15 years. By contrast, 9 years after scarification, the corresponding percentages measured in areas disturbed by the HuMinMix treatment were 91% and 100%, respectively. According to calculated linear regressions, the reindeer lichen cover could be completely re-established just one decade after HuMinMix treatment. Ground lichen diversity in the scarified areas was also inventoried. The significant increase in lichen diversity for HuMinMix, especially of early-successional species, could explain the more rapid re-establishment of late-successional lichens (e.g. Cladonia stellaris spp.), compared with disc trenching. Thus, the study demonstrates that both the degree of initial disturbance and the re-establishment rate of reindeer lichen must be considered when estimating the effects of scarification on lichen loss for reindeer grazing over time. 相似文献
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