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湿地松营养元素含量变化与生长关系的研究 总被引：2，自引：0，他引：2
以湖南省湘潭县湿地松不同配方施肥试验为研究对象，于不同生长季节分别在施肥区和对照区采集针叶进行Ｎ，Ｐ，Ｋ，Ｃａ，Ｍｇ，养分动态分析，并将各生长季节元素含量与树高，胸径进行相关性统计分析。结果表明：营养元素Ｎ，Ｐ，Ｋ，Ｃａ，Ｍｇ含量在不同生长季节变化是不同的，Ｎ，Ｐ，Ｋ，Ｃａ，Ｍｇ含量在生长初期最高，Ｎ，Ｐ９月最低，Ｋ，Ｃａ，Ｍｇ速生期最低，Ｃａ生长末期最高，Ｎ，Ｐ，Ｋ，Ｍｇ含量在生长季节逐渐减少， 相似文献
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高德祥 《云南林业调查规划设计》2001,26(1):20-23,35
由于石屏县大力开展飞播造林，人工造林，封山育林，森林面积由10年前的157311.3hm^2增加到现在的208753.7hm^2，森林资源增长呈现良好态势，分析了石屏县林业发展中存在的问题，财政困难，群众妯困，局部地方林权不清，缺泛科学规划，科技推广力度不够，林分结构单一，森林综合效益差，可采资源少，林业产值低，今后产值低，今后林业发展的思路为，走可持续发展道路，健全法制，以法治林，以洁兴要,攀筹集资金，注重人才培养，提高林业职工素质，保护好现有森林资源，大力发展经济林，有意识改主林分中树各结构。 相似文献
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在新形势下，如何实现林业由粗放型向集约型转变，提高林业经济效益，几年来，我站解放思想，大胆创新，不断更新观念，适应新形势，团结奋进，开拓进取，实干作奉献，改革求发展，实施重点突破战略，及时调整产业结构，加快林业产业化进程，走出了一条具有特色的自我转变... 相似文献
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广州中花历史修久，经“日伪”和“文革”两度摧残，损失惨重。改革开放后复苏，初步形成集约规模生产。但比世界花卉先进国家落后２０年，年出口量仅占香港消费总额的１０％，对世界消费市场，竞争乏力，关键是缺乏强有力政府领导，各自为战，科研滞后，经费不足，信息不灵，品种退化，种（籽）无保证，资源丰富，利用不多，进出渠道，还未澄清，扶持政策，亟待制订，基地规划，尚未形成。 相似文献
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轮胎消耗费用，在运材成本中占有较大比重，为了降低轮胎消耗，延长轮胎使用寿命，必须加强轮胎管理，做好轮胎的领发工作，各车轮胎需建卡烙号，单胎考核，节奖，超罚，需根据使用条件，道路技术等级合理选用与正确装配轮胎，每一条轮胎都应按标准高压充气，保证气压正常，防止超载。保持车辆底盘的技术状况良好，精心架驶，平稳起步，控制车速，注意选择路面，缓慢制动，定期保养，及时换位，以达到延长轮胎的使用寿命。 相似文献
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辽宁泥质海岸植物群落与土壤的关系及其在造林中的应用 总被引：1，自引：0，他引：1
对辽宁泥质海岸盐，碱生植被与土壤盐分，有机质等之间的相关性进行了定性和定量研究，结果表明，土壤含盐量，有机质，ｐＨ值，地下水位决定植物群落类型，空间分布及演替情况，生长成片翅碱蓬或碱蒿，稀疏的白刺，碱蓬群落，指示土壤含盐量在１．０％以上，不经改造不能造林，獐毛，茵陈蒿，补血草群落土壤含盐量为０．６５％左右，可直接栽柽柳枸杞，沙枣，修白田可栽群众杨，１０９柳等，白茅，罗布麻，狗尾草群落土壤含盐量０． 相似文献
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William R. Cobb Rodney E. Will Richard F. Daniels Marshall A. Jacobson 《Forest Ecology and Management》2008,255(12):4032-4039
We quantified the effect of water and nutrient availability on aboveground biomass and nitrogen accumulation and partitioning in four species from the southeastern United States, loblolly pine (Pinus taeda), slash pine (Pinus elliottii), sweetgum (Liquidambar styraciflua), and sycamore (Platanus occidentalis). The 6-year-old stands received five levels of resource input (control, irrigation with 3.05 cm water week−1, irrigation + 57 kg N ha−1 year−1, irrigation + 85 kg N ha−1 year−1, and irrigation + 114 kg N ha−1 year−1). Irrigation significantly increased foliage, stem, and branch biomass for sweetgum and sycamore, culminating in 103% and 238% increases in total aboveground biomass. Fertilization significantly increased aboveground components for all species resulting in 49, 58, 281, and 132% increases in total aboveground biomass for loblolly pine, slash pine, sweetgum, and sycamore, respectively. Standing total aboveground biomass of the fertilized treatments reached 79, 59, 48, and 54 Mg ha−1 for loblolly pine, slash pine, sweetgum, and sycamore, respectively. Fertilization increased foliar nitrogen concentration for loblolly pine, sweetgum, and sycamore foliage. Irrigation increased total stand nitrogen content by 6, 14, 93, and 161% for loblolly pine, slash pine, sweetgum, and sycamore, respectively. Fertilization increased total nitrogen content by 62, 53, 172, and 69% with maximum nitrogen contents of 267, 212, 237, and 203 kg ha−1 for loblolly pine, slash pine, sweetgum, and sycamore, respectively. Growth efficiency (stem growth per unit of leaf biomass) and nitrogen use efficiency (stem growth per unit of foliar nitrogen content) increased for the sycamore and sweetgum, but not the loblolly or slash pine. 相似文献
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The above- and belowground biomass and nutrient content (N, P, K, Ca, S and Mg) of pure deciduous Nothofagus antarctica (Forster f.) Oersted stands grown in a marginal site and aged from 8 to 180 years were measured in Southern Patagonia. The total biomass accumulated ranged from 60.8 to 70.8 Mg ha−1 for regeneration and final growth stand, respectively. The proportions of belowground components were 51.6, 47.2, 43.9 and 46.7% for regeneration, initial growth, final growth and mature stand, respectively. Also, crown classes affected the biomass accumulation where dominant trees had 38.4 Mg ha−1 and suppressed trees 2.6 Mg ha−1 to the stand biomass in mature stand. Nutrient concentrations varied according to tree component, crown class and stand age. Total nutrient concentration graded in the fallowing order: leaves > bark > middle roots > small branches > fine roots > sapwood > coarse roots > heartwood. While N and K concentrations increased with age in leaves and fine roots, concentration of Ca increased with stand age in all components. Dominant trees had higher N, K and Ca concentrations in leaves, and higher P, K and S concentrations in roots, compared with suppressed trees. Although the stands had similar biomass at different ages, there were important differences in nutrient accumulation per hectare from 979.8 kg ha−1 at the initial growth phase to 665.5 kg ha−1 at mature stands. Nutrient storage for mature and final growth stands was in the order Ca > N > K > P > Mg > S, and for regeneration stand was Ca > N > K > Mg > P > S. Belowground biomass represented an important budget of all nutrients. At early ages, N, K, S, Ca and Mg were about 50% in the belowground components. However, P was 60% in belowground biomass and then increased to 70% in mature stands. These data can assist to quantify the impact of different silviculture practices which should aim to leave material (mainly leaves, small branches and bark) on the site to ameliorate nutrient removal and to avoid a decline of long-term yields. 相似文献
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The effect of seed water content (WC) (2–3, 5–6 and 22–25%, on a fresh weight basis), storage temperature (+4, −20, −80 and
−196°C) and storage duration (6, 12, 24, 48 and 60 months) on the germination of white spruce (Picea glauca (Moench) Voss), black spruce (Picea mariana (Mill.) B.S.P.) and lodgepole pine (Pinus contorta Dougl. ex Loud. var. latifolia Engelm.) seed was investigated. Germination of white spruce control (untreated) seeds and seeds adjusted to 2–3% and 5–6%
WC declined after 48 months of storage at −80 and −196°C, with a further decline at 60 months at −20, −80, −196°C. Germination
remained high when control white spruce seeds and seeds with 2–3, 5–6% WC were stored at +4°C, over all storage durations.
Generally, black spruce and lodgepole pine exhibited high germination at all storage temperatures at 2–3% and 5–6% WC as well
as the control (untreated) seed, for up to 60 months in storage. Germination declined for all three species when seed was
conditioned to 22–25% WC. This loss in germination was partially recovered in white spruce seed stored at +4, −20 and −80°C
after storage durations of 24, 12 and 48 months, respectively, and in black spruce seeds stored at −20 and −196°C after storage
durations of 24 months. Mean germination time (MGT) was relatively constant for all species, under all conditions, except
for seed conditioned to 22–25% WC, where MGT increased for white spruce seed stored 48 months at −80 and −196°C, and for black
spruce seed stored 24 months at +4 and −80°C and 60 months at −196°C. These results show that the optimal storage temperatures
are 4°C for white spruce, and 4, −20, −80, and −196°C for black spruce and lodgepole pine, and 2–6% water content is optimal
for all 3 species at these temperatures. 相似文献
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在孟加拉诺阿卡利地区及相临裸地,对海岸植被(12年和17年生无瓣海桑Sonneratia apetala)进行探索性研究,以便了解海岸造林对土壤特性的影响.在三种不同地带(内陆、中部、海边),在12年生和17年生无瓣海桑林下,土壤深度分别为0-10,10-30和30-40cm,土壤湿度、土壤粒度、有机质、C含量、总N、pH、有效P、K、Na、Ca和Mg含量明显高(p≤0.05,p≤0.01,p≤0.001)于其相临裸地的数据,土壤含盐量明显(p≤0.01)低于其相临裸地的数据.在内陆CharAlim植被,土壤表面的土壤湿度,土壤粒度,有机质,C含量、总N、pH、土壤含盐量、有效P、K、Na、Ca和Mg含量分别为:31.09%、2.24 g·cm-3、2.41%、4.14%、0.58%、7.07、O.09 dS·cm-1、28.06 mg·L-1、O.50 mg·L-1、11.5 mg·L-1、3.30 mg·L-1和2.7 mmol·kg-1;而在相邻的Char Rehania贫瘠地区的相同土壤深度,其相关值分别为:16.69%、1.25g·cm-3、O.43%、0.74%、O.25%、6.57、0.13 dS·cm-1、13.07mg·L-1、O.30mg·L-1、1.4 mg·L-1、O.30 mmol·kG-1和0.50 nag·L-1.然而,在小内陆到海边的植被中,土壤湿度、土壤密度、有机质、C含量、总N、pH、有效P、K、Na和Ca含量逐渐降低,而土壤含盐量、Na和Mg含量却逐渐增加.虽然,在植被与相临裸地的不同土壤深度中土壤质地不同,植被地中砂土份额明显(p≤0.01)低于相临裸地,而粉砂土份额则明显(p≤0.001)高于裸地.在本研究中,所有参数的评价也在为其他地区相关研究得到应用. 相似文献
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John E. Major Alex MosselerDebby C. Barsi Britt Corriveau-DupuisMoira Campbell 《Forest Ecology and Management》2009
Our goal was to quantify and compare the impact of three silvicultural treatments (STs) on growth, light-energy processing, and needle-level morphological adaptive traits for eastern white pine (Pinus strobus L.) from large, central Ontario (ON) and small, isolated Newfoundland (NL) populations. The interest in STs is to reduce weevil (Pissodes strobi) incidence; however, there are potential adaptive changes and productivity trade-offs. The light levels for the STs were, on average, 100%, 42.0%, and 20.4% transmittance for the full-sun, and intermediate- and high-shade STs, respectively. After 8 years, overall height growth was 4.10, 3.25, and 1.70 m for full-sun, and intermediate- and high-shade STs, respectively (P < 0.001). Across all STs, ON populations had greater total height (14%), basal diameter (12%), current leader length (25%), and tree volume (49%) than NL populations (all P < 0.001). At low light levels (10 and 25 μmol m−2 s−1), high-shade ST trees had higher photochemical quenching (qP) and lower chlorophyll fluorescence (Fpc) compared with intermediate-shade and full-sun STs. At 100 μmol m−2 s−1 and beyond, full-sun ST trees had higher qP and lower Fpc than intermediate- and high-shade STs. Average total chlorophyll concentration (CHL) and content (CHLC), and carotenoid concentration (CAR), increased in response to the intermediate-shade ST but did not respond further, or decreased in the high-shade ST. Region was significant for CHL, CAR, chlorophyll a:b and CHL:CAR ratios and CHLC, with ON greater than NL, but was reversed for CHL:CAR ratio. Tree height and volume showed a curvilinear and linear relationship to light level, respectively. Tree height showed a positive linear relationship to qP, apparent photosynthesis, chlorophyll a:b ratio, and needle N (all P < 0.001). Tree height showed a negative linear relationship to Fpc, CHL:CAR ratio, specific needle area, C:N ratio, and needle area N−1 (all P < 0.001). There were modest trade-offs between weevil protection and productivity in the intermediate ST due to the compensatory physiological and morphological adaptations to the limiting light, however, the trade-off with growth at the high-shade level was severe. For NL, consideration should now be given to the introduction and mixing of seed from local seed sources with more southern mainland seed sources, which would decrease the inbreeding effect and provide wider variation for natural selection for a more fit future population. 相似文献
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P.L. Mafongoya R. Chintu T.S. Chirwa J. Matibini S. Chikale 《Agroforestry Systems》2003,59(3):279-288
Seeking an alternative to Sesbania spp. tree fallows, a Tephrosia species and provenance trial was conducted at Msekera Research Station, Chipata (Zambia) to evaluate eleven Tephrosia vogelii and three Tephrosia candida provenances. They were tested for biomass production, quality of biomass, resistance to root-knot nematodes, nitrogen release,
and for their effects on soil nitrogen dynamics. At the end of 1.5 years, the T. candida provenances 02970, 02971 and 02972 from Madagascar produced two times greater amount of aboveground biomass than the T. vogelii provenances. There was little variability among the T. vogelii provenances in terms of litter and biomass production. Weed growth was significantly greater under T. vogelii than T. candida provenances. While Tephrosia vogelii provenance 98/02 from Zambia and T. candida 02972 were highly tolerant to the Meloidogyne incognita nematodes, T. vogelii provenances 02977, 98/03, 02973 from Kenya, Zambia and Malawi, respectively, were highly susceptible to the nematodes. The
Tephrosia species and provenances showed a wide variability in terms of N, lignin and polyphenol concentration in their foliage. Mineralization
of N in the foliage of T. candida provenances 02970 and 02971 and T. vogelii provenances 98/04 and 02974 from Malawi occurred rapidly within 14 weeks of incubation. At the end of the 2-year growth period,
there was significantly greater total inorganic N under T. candida provenance 02972 (12.5 mg kg−1) than T. vogelii (5 mg kg−1) provenance Mungwi 98/02. Maize (Zea mays L.) yields after T. candida provenances were greater than those after T. vogelii provenances. Further testing of the most promising provenances is needed for their effects on subsequent maize yields under
a range of farm conditions.
This revised version was published online in June 2006 with corrections to the Cover Date. 相似文献
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Effects of Ca^2＋concentrations on accumulations of mineral elements in the components of Pteroceltis tatarinowii 总被引：2，自引：0，他引：2
The bark ofPteroceltis tatarinowii is a raw material for manufacturing Xuan Paper. The effects of Ca2+ concentrations on the accumulation of mineral elements in the bark, leaf and root ofPteroceltis tatarinowii were studied under controlled conditions. The types of Hoagland nutrient solution with three Ca2+ concentrations levels (200, 400 and 600 μg·g−1) and a control (without Ca2+ were designed to culturePteroceltis tatarinowii. After 6 months, contents of seven mineral elements including Ca, K, Mg, Mn, Zn, Cu and Na in the root, leaf and bark were
analyzed. The results indicated that Ca accumulations content in the root, leaf and bark had positively relation with Ca2+ concentrations (200, 400, 600 μg·g−1), and the order of the Ca content in the three components was root>leaf>bark. Ca content in the root treated with 600 μg·g−1 Ca2+ concentrations was 5.5 times as high as that of the control, and about 1.4 times as high as that of the root treated in 200
and 400 μg/g Ca2+ concentrations respectively. On the contrary, K and Mg contents in the root, leaf and bark were negatively related to Ca2+ concentrations, especially in the bark, and their accumulation trend followed the order of leaf>root>bark. K content in the
bark treated with 600 μg·g−1 Ca2+ concentrations was 39.3% of that of the control, and was 79.0% and 91.8% of that of the bark treated with 200μg·g−1 and 400μg·g−1 Ca2+ concentrations respectively; Mg content in the bark treated with 600μg·g−1 Ca2+ concentrations was 23.4% of that of the control, and was 27.1% and 35.4% of that of the bark treated with 200 and 400 μg·g−1 Ca2+ concentrations respectively. Compared with the control, the general tendency of Mn, Zn and Cu content decreased with increasing
of Ca2+ concentrations and their contents were in the order: root>leaf>bark. Based on the results of this study, the experiment has
been useful for providing academic bases in improving the bark quality ofPteroceltis tatarinowii on non-limestone soil.
Foundation item: This paper is supported by National Natural Science Foundation of China (No. 39970608).
Biography: Fang Shengzun (1963), male, Professor in Stiiviculture, Nanjing Forestry University, Nanjing 210027, P.R. China.
Responsible editor: Zhu Hong 相似文献
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Kana Yamashita Yasuhiko Hirakawa Hiroshi Nakatani Motoyoshi Ikeda 《Journal of Wood Science》2009,55(3):161-168
The transverse shrinkage variation within trees was examined for five sugi cultivars. The within-tree trends of tangential
shrinkage (α
T) were different by cultivar, whereas radial shrinkage (α
R) increased from pith to bark in most cultivars. The tangential/radial shrinkage ratio (α
T/α
R) decreased from pith to bark in most cultivars, because the radial variation of α
R was larger than that of α
T. The cultivars showed significant differences among cultivars in α
T, α
R, and α
T/α
R, but the difference among cultivars for α
T/α
R was smaller. The relationships between transverse shrinkage and microfi bril angle (MFA), basic density (BD), tree ring parameters,
and modulus of elasticity were examined. The α
T and α
R showed positive relationships with BD, latewood percentage, latewood density, and modulus of elasticity, and negative relationships
with MFA and ring width. The relationships with earlywood density were weak. Sugi exhibited variation in transverse shrinkage
within stem and among cultivars, with the variation affected by MFA, density, and tree ring parameters.
Part of this article was presented at the 56th Annual Meeting of the Japan Wood Research Society, Akita, Japan, August 2006,
and the 57th Annual Meeting of the Japan Wood Research Society, Hiroshima, Japan, August 2007 相似文献
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Ameur M. Manceur Greg J. Boland Naresh V. Thevathasan Andrew M. Gordon 《Agroforestry Systems》2009,76(2):295-301
In 2004 and 2005, the yield, leaf area, dry weight and dry weight partitions of soybeans were determined at the Agroforestry
Research Site (ARS) (est. 1987, Ontario, Canada). Soybean was intercropped with poplar (Populus deltoides x nigra DN-177 L., 556 m3crown tree−1), silver maple (Acer saccharinum L., 308 m3), black walnut (Juglans nigra L., 148 m3) and pecan (Carya illinoensis Wangenh., 114 m3), or grown alone (monoculture). Yield of soybean was not different in either year between the monoculture and the black walnut
or pecan intercrops. In the poplar and silver maple treatments, yield was 66 and 85% (2004 and 2005) lower than in the monoculture.
Despite the fact that different tree species were used, there was a significant negative linear regression between yield and
tree crown volume (R
2 = 0.76, P = 0.0049 and R
2 = 0.93, P < 0.0001 in 2004 and 2005, respectively). With increasing tree crown volume, soybean tended to partition more dry matter
to the photosynthetic and reproductive parts and less to structural tissue and petiole. This demonstrates the phenotypic flexibility
of the crop component in agroforestry systems. Contrary to theoretical predictions, soybean leaves were thicker as shade increased
(increase by 6.2 × 10−4–1.2 × 10−3 mg cm−2, per unit of crown volume), pointing to competitive interactions specific to tree-based intercrops. 相似文献
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This study was conducted to determine carbon (C) dynamics following forest tending works (FTW) which are one of the most important forest management activities conducted by Korean forest police and managers. We measured organic C storage (above- and below-ground biomass C, forest floor C, and soil C at 50 cm depth), soil environmental factors (soil CO2 efflux, soil temperature, soil water content, soil pH, and soil organic C concentration), and organic C input and output (litterfall and litter decomposition rates) for one year in FTW and non-FTW (control) stands of approximately 40-year-old red pine (Pinus densiflora S. et Z.) forests in the Hwangmaesan Soopkakkugi model forest in Sancheonggun, Gyeongsangnam-do, Korea. This forest was thinned in 2005 as a representative FTW practice. The total C stored in tree biomass was significantly lower (P < 0.05) in the FTW stand (40.17 Mg C ha−1) than in the control stand (64.52 Mg C ha−1). However, C storage of forest floor and soil layers measured at four different depths was not changed by FTW, except for that at the surface soil depth (0–10 cm). The organic C input due to litterfall and output due to needle litter decomposition were both significantly lower in the FTW stand than in the control stand (2.02 Mg C ha−1 year−1 vs. 2.80 Mg C ha−1 year−1 and 308 g C kg−1 year−1 vs. 364 g C kg−1 year−1, respectively, both P < 0.05). Soil environmental factors were significantly affected (P < 0.05) by FTW, except for soil CO2 efflux rates and organic C concentration at soil depth of 0–20 cm. The mean annual soil CO2 efflux rates were the same in the FTW (0.24 g CO2 m−2 h−1) and control (0.24 g CO2 m−2 h−1) stands despite monthly variations of soil CO2 efflux over the one-year study period. The mean soil organic C concentration at a soil depth of 0–20 cm was lower in the FTW stand (81.3 g kg−1) than in the control stand (86.4 g kg−1) but the difference was not significant (P > 0.05). In contrast, the mean soil temperature was significantly higher, the mean soil water content was significantly lower, and the soil pH was significantly higher in the FTW stand than in the control stand (10.34 °C vs. 8.98 °C, 48.2% vs. 56.4%, and pH 4.83 vs. pH 4.60, respectively, all P < 0.05). These results indicated that FTW can influence tree biomass C dynamics, organic C input and output, and soil environmental factors such as soil temperature, soil water content and soil pH, while soil C dynamics such as soil CO2 efflux rates and soil organic C concentration were little affected by FTW in a red pine stand. 相似文献