共查询到20条相似文献，搜索用时 31 毫秒
1.
Variations in several growth, gas exchange and leaf traits among greenhouse-grown black locust (Robinia pseudoacacia L.) seedlings from 11 half-sib families were investigated. Three weeks after germination, early growth rates ranged from a minimum of 1 cm d(-1) in the slowest growing family, to a maximum of 3 cm d(-1) in the fastest growing family. Significant family variation in net photosynthetic rate per unit leaf area (P(N)), stomatal conductance, chlorophyll content, height, diameter, stem dry weight and total dry weight was observed. Net photosynthetic rate declined with seedling age. Net photosynthetic rate per unit leaf area was significantly correlated (r < 0.4) with specific leaf area, total chlorophyll, root dry weight, foliage dry weight and total dry weight. The correlation coefficients were higher (r >/= 0.55) between P(N) x total leaf area and growth traits (height, stem dry weight, foliage dry weight and total dry weight). The study indicated that variation in leaf area among the families was one reason for the lack of a strong relationship between P(N) and growth. 相似文献
2.
Photosynthesis of tree seedlings is generally enhanced during short-term exposure to elevated atmospheric CO2 partial pressure, but longer-term studies often indicate some degree of photosynthetic adjustment. We present physiological and biochemical evidence to explain observed long-term photosynthetic responses to elevated CO2 partial pressure as influenced by needle age and canopy position. We grew Pinus radiata D. Don. trees in open-top chambers for 5 years in sandy soil at ambient (36 Pa) and elevated (65 Pa) CO2 partial pressures. The trees were well watered and exposed to natural light and ambient temperature. In the fourth year of CO2 exposure (fall 1997), when foliage growth had ceased for the year, photosynthetic down-regulation was observed in 1-year-old needles, but not in current-year needles, suggesting a reduction in carbohydrate sink strength as a result of increasing needle age (Turnbull et al. 1998). In 5-year-old trees (spring 1997), when foliage expansion was occurring, photosynthetic down-regulation was not observed, reflecting significantly large sinks for carbohydrates throughout the tree. Net photosynthesis was stimulated by 79% in trees growing in elevated CO2 partial pressure, but there was no significant effect on photosynthetic capacity or Rubisco activity and concentration. Current-year needles were more responsive to elevated CO2 partial pressure than 1-year-old needles, exhibiting larger relative increases in net photosynthesis to elevated CO2 partial pressure (98 versus 64%). Lower canopy and upper canopy leaves exhibited similar relative responses to growth in elevated CO2 partial pressure. However, needles in the upper canopy exhibited higher net photosynthesis, photosynthetic capacity, and Rubisco activity and concentration than needles in the lower canopy. Given that the ratio of mature to juvenile foliage mass in the canopy will increase as trees mature, we suggest that trees may become less responsive to elevated CO2 partial pressure with increasing age. We conclude that tree response to elevated CO2 partial pressure is based primarily on sink strength and not on the duration of exposure. 相似文献
3.
Bamboo hedgerow systems in Kerala, India: Root distribution and competition with trees for phosphorus 总被引：1，自引：0，他引：1
B. N. Divakara B. Mohan Kumar P. V. Balachandran N. V. Kamalam 《Agroforestry Systems》2001,51(3):189-200
In a field study on bamboo (Bambusa arundinacea (Retz.) Willd.) hedgerow systems of Kerala, we tested the following three hypotheses: (1) Effective root foraging space is
a function of crown spread, (2) Proximity of trees depress lateral spread of roots in mixed species systems and (3) The closer
the trees are located the greater will be the subsoil root activity which in turn facilitates active absorption of nutrients
from deeper layers of the soil profile. Root distribution of boundary planted bamboo and root competition with associated
trees in two binary mixtures, teak (Tectona grandis)-bamboo and Malabar white pine (Vateria indica)-bamboo, were evaluated using modified logarithmic spiral trenching and 32P soil injection techniques respectively. Excavation studies indicate that rooting intensity declined linearly with increasing
lateral distance. Larger clumps manifested wider foraging zones. Eighty three per cent of the large clumps (>4.0 m dia.) extended
roots beyond 8 m while only 33% of the small (<2.5 m dia.) clumps extended roots up to 8 m. Highest root counts were found
in the 10–20 cm layer with nearly 30% of total roots. Although nearness of bamboo clumps depressed root activity of teak and
Vateria in the surface layers of the soil profile, root activity in the deeper layers was stimulated. 32P recovery was higher when applied at 50-cm depth than at 25-cm depth implying the safety net role of tree roots for leached
down nutrients. Inter specific root competition can be regulated by planting crops 8–9 m away from the bamboo clumps and/or
by canopy reduction treatments.
This revised version was published online in June 2006 with corrections to the Cover Date. 相似文献
4.
Carbon isotope composition (delta13C) of branchlet tissue at nine canopy positions, and nitrogen concentration (N(mass)) at four canopy positions, were assessed in 8-year-old hoop pine (Araucaria cunninghamii Ait. ex D. Don) trees from 23 half-sib families, grown in six blocks of a progeny test in southeastern Queensland, Australia. There was considerable variation among sampling positions, families and blocks in both delta13C and N(mass). The delta13C was positively related to N(mass) only for samples from the upper outer crown (P < 0.005). Phenotypic correlations existed between tree growth and canopy delta13C. Branchlet delta13C of the inner and lower outer crown was positively related (P < 0.037) to tree height, but delta13C in branchlets of the upper outer crown was not related to tree height, or was related negatively (P < 0.045). There were significant differences in delta13C between hoop pine families for six canopy positions (upper canopy positions as well as lower canopy positions on the northern side), with heritabilities greater than 0.40. The significance of these findings is discussed in relation to water and light competition within the tree canopy of hoop pine. 相似文献
5.
We examined effects of mist quantity, topophysis (origin of cutting in the crown of 6-year-old trees), maturation state of the donor stock, and time of sticking on rooting and root system quality of cuttings representing five full-sib hybrid larch families obtained with Larix decidua Mill., L. laricina (du Roi) K. Koch, and L. kaempferi (Lamb.) Sarg. (Sieb. and Zucc.) Gord., as parents. Mist frequency, supplemental watering and family all had highly significant effects on percentage of cuttings rooting and root system quality. The high-frequency misting regime yielded both higher rooting percentages and higher quality root systems than the low-frequency regime without supplemental watering. Supplemental watering of the rooting medium in the low-frequency misting regime increased both percent rooting and root system quality to values comparable with those obtained by cuttings in the high-frequency misting regime. Rooting of cuttings from the top, middle and bottom whorls of 5-year-old plantation grown trees tended to decline with increasing height for three of the five families. Overall, height of cutting origin did not significantly affect rooting, but when analyzed separately, two families exhibited a significant decline in rooting toward the top of the trees. Age of donor ortet (ranging from 1 to 7 years) significantly affected both percent rooting and root system quality. Rooting percentages declined linearly with age, and root system quality declined more sharply than percent rooting. The relatively poor root system quality of cuttings from ortets older than 1 year was closely associated with plagiotropic growth. Softwood cuttings (stuck in mid-July) rooted better than hardwood cuttings (stuck in early September) across all families. 相似文献
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We examined photosynthetic characteristics of two fast- and two slow-growing half-sib families of both loblolly pine (Pinus taeda L.) and slash pine (Pinus elliottii var. elliottii Engelm.) on two sites in northern Florida to: (1) quantify variation in light-saturated net photosynthesis (Amax) associated with vertical crown position and foliage age; (2) quantify the amount and distribution of leaf area by foliage age class; and (3) determine whether photosynthetic indices, ranging from leaf-level through whole-crown Amax, were related to growth differences among species and families. In both species, leaf-level Amax was higher in more recently formed foliage both within the same year (where Amax in the third flush averaged 10 to 30% higher than Amax in the first flush) and between years (where Amax in current-year foliage averaged 20 to 40% higher than Amax in 1-year-old foliage). When expressed on a leaf area basis, Amax of current-year foliage was higher in slash pine than in loblolly pine, but Amax expressed on a mass basis did not differ between species. Loblolly pine had higher whole-tree leaf area than slash pine, whereas whole-tree Amax did not differ between species. When the mean values for fast-growing families were compared with the mean values for slow-growing families, there were no differences in leaf-level characteristics, whereas at the whole-tree level, fast-growing families had higher leaf area and whole-tree Amax than slow-growing families in both species. When comparisons were made among the individual fast- and slow-growing families, however, results were more variable. In both species, stem volume growth was strongly correlated with whole-tree Amax, with most of the strength of the correlation deriving from the relationship between volume growth and tree leaf area. 相似文献
8.
通过对从云南昌宁、云南龙陵引进的17个秃杉半同胞家系实生林的长期观测,进行了秃杉生长形状的遗传分析及初步选择。结果表明:各半同胞家系在第5、15、24年,生长性状差异达到显著水平以上,这些差异主要由其本身的遗传特性决定,受中、强遗传力的控制,而受环境控制较弱。所有半同胞家系中,24年生14号、2号、17号、16号的树高、胸径和材积的均值分别为13.64 m、18.29 cm和0.1877 m^3,遗传增益的平均值分别为5.2%、4.38%和15.85%;选择出6株优良个体,24年生树高、胸径和材积的平均值分别为17.6 m、29.12 cm和0.5886 m^3,遗传增益的平均值分别为14.13%、14.73%和69.83%,这些优良半同胞家系和优良个体表现出突出的生长优势,可作为种子园和采穗圃材料。 相似文献
9.
[目的]探究模拟干旱环境下注水伐桩对1、2和3年生毛竹生理特性的影响,为气候变化背景下毛竹的适应性经营管理及毛竹林节水灌溉措施的制定提供理论参考。[方法]在毛竹林中选取面积相同(10 m×20 m)的样地9块,以1、2和3年生毛竹为试验材料,采用覆盖薄膜模拟干旱环境,对各样地四周进行挖沟切鞭处理,以阻断周边土壤水分的运输,试验设置CK(0个伐桩注水)、T1(12个伐桩注水)和T2(18个伐桩注水)3个灌水量处理,每个处理均进行3次重复,研究不同数量注水伐桩下3个年龄毛竹的生理响应。[结果]试验表明,在模拟干旱环境下,随着注水伐桩数量的减少,3个年龄毛竹的净光合速率与蒸腾速率显著下降,1、2和3年生毛竹的净光合速率与蒸腾速率最大降幅分别达到74.35%和73.08%、59.14%和36.62%及60.47%和61.54%;毛竹叶片叶绿素a、叶绿素b和类胡萝卜素含量显著下降,1年生和3年生毛竹叶片叶绿素a、叶绿素b和类胡萝卜含量差异均达到显著水平(P0.05),2年生毛竹叶片叶绿素a含量差异显著(P0.05),但叶绿素b和类胡萝卜素含量差异不显著(P0.05),3个年龄毛竹叶片叶绿素a/b差异均不显著(P0.05);毛竹叶片丙二醛(MDA)含量及超氧化物歧化酶(SOD)、过氧化氢酶(CAT)和过氧化物酶(POD)活性显著上升,且均达到差异显著水平(P0.05)。同时发现3个年龄毛竹的净光合速率、蒸腾速率和叶片光合色素含量与注水伐桩数量正相关,而叶片MDA含量及SOD、CAT和POD活性与注水伐桩数量负相关。[结论]模拟干旱环境下,增加注水伐桩可以使1、2和3年生毛竹光合蒸腾能力提高,光合产物积累增加,叶片光合色素含量升高,叶片MDA含量及SOD、CAT和POD活性降低。 相似文献
10.
Juan Carlos Loaiza Usuga Jorge Andrés Rodríguez Toro Mailing Vanessa Ramírez Alzate Álvaro de Jesús Lema Tapias 《Forest Ecology and Management》2010
An accurate characterization of tree carbon (TC), forest floor carbon (FFC) and soil organic carbon (SOC) in tropical forest plantations is important to estimate their contribution to global carbon stocks. This information, however, is poor and fragmented. Carbon contents were assessed in patula pine (Pinus patula) and teak (Tectona grandis) stands in tropical forest plantations of different development stages in combination with inventory assessments and soil survey information. Growth models were used to associate TOC to tree normal diameter (D) with average basal area and total tree height (HT), with D and HT parameters that can be used in 6–26 years old patula pine and teak in commercial tropical forests as indicators of carbon stocks. The information was obtained from individual trees in different development stages in 54 patula pine plots and 42 teak plots. The obtained TC was 99.6 Mg ha−1 in patula pine and 85.7 Mg ha−1 in teak forests. FFC was 2.3 and 1.2 Mg ha−1, SOC in the surface layer (0–25 cm) was 92.6 and 35.8 Mg ha−1, 76.1 and 19 Mg ha−1 in deep layers (25–50 cm) in patula pine and teak, respectively. Carbon storage in trees was similar between patula pine and teak plantations, but patula pine had higher levels of forest floor carbon and soil organic carbon. Carbon storage in trees represents 37 and 60% of the total carbon content in patula pine and teak plantations, respectively. Even so, the remaining percentage corresponds to SOC, whereas FFC content is less than 1%. In summary, differences in carbon stocks between patula pine and teak trees were not significant, but the distribution of carbon differed between the plantation types. The low FFC does not explain the SOC stocks; however, current variability of SOC stocks could be related to variation in land use history. 相似文献
11.
Xuanxuan Xia Kexiang Gao Xianshuang Xing Rui Yang Shuyong Zhang Zilong Du Jing Guo Xia Liu 《林业研究》2018,(4)
Previous studies showed that Chaetomium globosum ND35 fungus fertilizer can improve the microbial community structure and enzyme activities of replanted soil.However, it remains unclear whether can improve the physiological and ecological characteristics of plants under successive rotation.In this study, we investigated the photosynthetic, physiological, and biochemical indexes including photosynthetic parameters, chlorophyll fluorescence, and chlorophyll content of 1-year-old poplar seedlings under seven different doses(range from 0 to1.67 g kg~(-1)) of C.globosum ND35 fungus fertilizer to study the effects of fungus fertilizer on photosynthesis of Poplar.Our results showed that:(1) With increasing application of fungus fertilizer in replanted soil, chlorophyll content of poplar leaves(Chl) increased, while physiological indexes such as electron transport rate(ETR),net photosynthetic rate(P_n), quantum efficiency(U),nitrate reductase(NR) activity and root vigor initially increased and then declined.Meanwhile, heat dissipation that depended on the xanthophyll cycle declined and nonphotochemical quenching(NPQ) initially increased and then decreased.When the dose of C.globosum ND35 fungus fertilizer was 0.67 g kg~(-1)(T3) and 1.00 g kg~(-1)(T4), excess light energy of photosynthetic apparatus was reduced, and photosynthetic apparatus distributed more light energy to the direction of photochemical reactions,which improved the efficiency of energy use.Plant height and biomass of leaves, stems, and roots were maximum at T3.We conclude that applying appropriate amounts of C.globosum ND35 fungus fertilizer can improve root physiological activity and capacity for use of light by poplar leaves.This can improve the operating states of the photosynthetic apparatus and lead to increased photosynthetic efficiency of poplar leaves and accumulation of dry matter.This suggests a strategy to alleviate the successive rotation obstacle of soil nutrient depletion. 相似文献
12.
《Forest Ecology and Management》1998,108(3):215-222
Seedling anatomy and cross sectional discs of 8- and 12-year-old (juvenile) teak trees were examined for tree ring analysis and determination of environmental factors responsible for false ring formation in teak. Based on the anatomy and location within the true annual rings, four types of false rings were identified. The results from both cross-dating of plantation grown trees and controlled experiments, including induced drought, showed that rainfall during dry period, drought during active growing season, (container) polybag/field transplantation of seedlings and juvenility are the important causative factors of frequent false rings in teak. No definite relationship could be established between insect defoliation and the incidence of false rings. False ring formation in teak appears to be mainly a resultant feature of tree ring responses to different environmental and physical factors. 相似文献
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14.
We evaluated heartwood, sapwood and bark content in teak trees. A total of 27 sample plots were laid out in teak plantations raised by State Forest Department in Karnataka covering different age groups... 相似文献
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Apple M Tiekotter K Snow M Young J Soeldner A Phillips D Tingey D Bond BJ 《Tree physiology》2002,22(2-3):129-136
Morphological differences between old-growth trees and saplings of Douglas-fir (Pseudotsuga menziesii (Mirb.) Franco) may extend to differences in needle anatomy. We used microscopy with image analysis to compare and quantify anatomical parameters in cross sections of previous-year needles of old-growth Douglas-fir trees and saplings at the Wind River Canopy Crane site in Washington and at three sites in the Cascade Mountains of Oregon. We also compared needle anatomy across a chronosequence of 10-, 20-, 40- and 450-year-old Douglas-fir trees from the Wind River site. Anatomy differed significantly between needles of old-growth trees and saplings at all sites, suggesting a developmental change in needle anatomy with increasing tree age. Compared with needles of old-growth trees, needles of saplings were longer and had proportionately smaller vascular cylinders, larger resin canals and few hypodermal cells. Astrosclereids, which sequester lignin in their secondary cell walls and occupy space otherwise filled by photosynthetic cells, were scarce in needles of saplings but abundant in needles of old-growth trees. Needles of old-growth trees had an average of 11% less photosynthetic mesophyll area than needles of saplings. The percentage of non-photosynthetic area in needles increased significantly with increasing tree age from the chronosequence of 10-, 20-, 40- and 450-year-old trees at the Wind River site. This reduction in photosynthetic area may contribute to decreased growth rates in old trees. 相似文献
17.
Photosynthetic gas exchange, stable carbon isotope discrimination (Delta), height and diameter were compared among five open-pollinated families of 12-year-old western larch trees growing in a common garden in Moscow, Idaho, USA. Statistically significant variation was detected among the families in the two growth traits, Delta and stomatal conductance to water vapor (g) (P /= 0.203). Water-use efficiency was strongly correlated with Delta (r = -0.95, P < 0.01). Neither growth trait was correlated with A (r 0.93) and height was not significantly correlated with Delta (r = -0.75, P = 0.15). Tree diameter and Delta were significantly correlated (r = -0.92, P = 0.03). These results were strongly influenced by a single family. Both the variation in Delta and correlation trends between Delta and the growth traits height and diameter suggest the possibility of selecting for high water-use efficiency with the potential for simultaneous gains in height and diameter growth. 相似文献
18.
Growth, wood quality parameters and productivity estimations of 12-year-old teak (Tectona grandis L.f.) grown under three agroforestry systems, namely unmanaged block (Bum), unmanaged line on the farm boundary (Lum) and intensively managed block (Bim) plantations are studied. Mean annual increment (MAI) of 0.020, 0.006 and 0.016 m3 tree?1 year?1 was recorded in Lum, Bum and Bim, respectively. Overall growth performance of teak raised in Lum, plantation appears to be better than two block plantations (Bum and Bim). For evaluating various wood quality parameters, tree logs from each plantation were tested for different physical and mechanical properties according to the standard procedures. The wood quality of Bum was found to be comparatively superior to Bim and much better than those of Lum. The 12-year-old farm teak trees from three systems exhibited lower average values of different wood quality parameters compared to mature forest teak. Since physical and strength properties of Bum were inferior compared to Lum and Bim, its exploitation is not advisable at this stage. Line plantation, however, releases land for cultivation of arable crops and does not demand any special silvicultural management as required by Bim. Although, total extractable volume of teak wood available after 12-years of age from Bum was much smaller compared to Bim or Lum, its commercial exploitation at an early age may be preferred over other two practices due to better wood quality and lower management cost. For optimum economic utilization and mechanical maturity of wood, harvesting of block plantation may be delayed for about 10-15 years because growth volume and strength properties are expected to improve with age of tree. 相似文献
19.
Alexander Berrocal Johana Gaitan-Alvarez Roger Moya David Fernandez-Solis Edgar Ortiz-Malavassi 《林业研究》2020,31(2):667-676
To elucidate the development of heartwood,bark,sapwood,pith and specific gravity of wood in fastgrowing teak(Tectona grandis)plantations in Costa Rica,we sampled three trees in each of 55 plantations and modelled each variable with age,site and different tree heights.Age and stand density of plantations were significant correlated with stem diameter at breast height and total height of the tree.Formation of heartwood was initiated at the age of 4-year-old and increased in direct proportion with age.The age of plantation had a significant relationship with stem diameter at breast height,heartwood percentage,sapwood thickness,sapwood percentage,percentage of bark,pith diameter and percentage,and specify gravity.The model for these tree parameters was model with these parameters as dependent variable and in relation to age as independent variable. 相似文献
20.
Non destructive methods for quantification of carbon seques-tration in tropical trees are inadequately developed. We described a stan-dardized method for estimating carbon stock in teak (Tectona grandi... 相似文献