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油茶林地土壤电导率与其养分含量的相关性 总被引：1，自引：0，他引：1
为了找到一种快捷的林地养分含量检测方法,减少土壤养分含量测定的成本与工作量,以油茶林地土壤为对象,采用土壤养分常规分析和电导法,测定土壤样品的N、P、K养分含量及相对电导率,建立区域性土壤养分含量与电导参数的预测模型,通过测定样品的电导率快速预测该区域土壤的养分含量。结果表明,油茶林地土壤样品N、P、K养分含量与电导率的相关性良好,且均遵循多项式拟合模型。经实测验证,预测模型精度达90%以上。因此,生产上可根据需求建立特定区域土壤养分与电导率的预测模型,实现实时养分监测。 相似文献
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油茶叶片营养诊断分析样品适宜采集期研究 总被引：3，自引：0，他引：3
为了确定油茶叶片营养诊断分析样品的适宜采集期,采用定点定期连续叶片样品采集方法,测定并比较分析了油茶叶片中的N、P、K、Ca和Mg养分含量的动态变化特征。结果表明:油茶叶片中的N、P、K素含量随其年生长发育进程呈"升高—下降—升高"的趋势,Ca素含量的变化特点是先降低后升高,Mg素含量的变化特点则为先升高后下降。油茶叶片中养分元素含量在6月和8月间的数值变化较小,6～8月可为N素养分测定的适宜采样期;6、8和10月P素变化相对平缓,此时为P养分测定的适宜采样期;K、Ca和Mg养分测定以8月采样为宜。综合分析结果表明,以油茶叶片营养诊断分析为目的的样品适宜采集期为6～8月。 相似文献
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油茶树体氮磷钾养分的年动态变化 总被引：1，自引：0，他引：1
为给油茶生产中采取合理的生产栽培措施提供指导,提高油茶产量,改善果实品质,以普通油茶为材料,测定油茶植株生长过程中N、P、K元素在各部位的含量,研究其在油茶树体中的时空变化规律。结果表明:在油茶树体中,各营养元素总含量最大为K元素,N元素次之,P元素最少。从油茶叶片营养含量变化情况来看,3—5月,叶片吸收的N、P、K元素不断增多;6月,叶片N、P、K元素积累达到最大。从树体部位来看,果实需要养分最多。在生长发育过程中,果实对矿质营养的需求不同,K、N、P的需求量依次为31.60、17.11、7.90 g/kg。 相似文献
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广西孟江油茶叶片营养DRIS诊断 总被引：1，自引：0，他引：1
以广西三江侗族自治县40年生孟江油茶(Camellia leifera Abel)成林叶片为对象,对该油茶产区高产组和低产组油茶叶片的9种养分(N、P、K、Ca、Mg、Cu、Zn、Fe、Mn)进行DRIS诊断。结果表明:油茶林N、P、Fe相对缺乏,K、Ca、Mg、Cu、Zn、Mn相对充足,其中养分P、Fe元素在高、低组间差异显著,N、P和Fe元素缺乏是提高油茶产量的最大限制因子;树体需肥顺序为:NPFeZnCuCaMnKM;同时,利用高产组叶片养分浓度、养分诊断指数及其等级制定了相应的养分诊断标准,可为三江侗族自治县指导油茶施肥管理提供参考。 相似文献
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【目的】研究氮添加对油茶幼苗养分积累和主要大量营养元素含量、比值等计量特征的影响,为探究氮对油茶苗生长的影响机理及其与碳、磷等互作关系提供科学参考,同时可为油茶苗氮素养分管理提供理论依据。【方法】以油茶2年生实生苗为试验材料,设置0 mmol·L-1(N0,CK)、5 mmol·L-1(N1)、10 mmol·L-1(N2)、15 mmol·L-1(N3)、20 mmol·L-1(N4)共5个氮浓度处理,开展盆栽试验。测定油茶苗各器官生物量和碳氮磷钾元素含量,计算养分累积量、养分利用效率和元素化学计量比。【结果】氮添加显著提升油茶体内N素含量,各器官N含量均在N3水平下达到峰值。随着氮水平的升高,根系C、P含量和叶片P含量呈下降趋势,叶片C和茎部C、P、K含量保持不变。中高浓度氮素(N3、N4)能促进油茶苗干物质和养分的积累,N4处理促进作用最大。氮浓度处理改变了养分的分配格局,随着氮水平的升高,根系养分占比下降,叶片养分比例升高。氮添加降低了N素利用效率,对P、K利用效率影响... 相似文献
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为了给油茶林施肥管理提供科学依据,通过不同模式施肥,对油茶叶片生长和叶片养分含量进行研究,探讨油茶叶片各生长指标与叶片养分含量之间的关系。结果表明:各模式对油茶叶片生长指标和叶片养分含量均有显著促进作用,叶形指数与其它指标有负显著相关性,比叶重与其它指标间有正显著相关性,叶片养分中N、P、K的含量与其它指标间均存在显著相关性,说明施肥模式与叶片生长间关系密切。各模式对油茶叶片的肥效作用由大到小排列依次为:M5、M4、M2、M3、M1、M0、CK。 相似文献
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《中南林业科技大学学报(自然科学版)》2016,(1)
以11个山茶属植物为试材,测定其叶片稳定碳氮同位素比率(δ13C和δ15N)、光合参数(净光合速率、气孔导度、蒸腾速率、胞间CO2浓度、水分利用效率)以及叶片C、N、P和K元素含量等指标,分析叶片δ13C和δ15N与光合参数、养分含量之间的关系。结果表明:11个山茶属植物δ13C值在-26.38‰~-29.44‰之间,其中多齿红山茶显著高于其它10个物种;δ15N在-3.01‰~4.27‰之间,其中以攸县油茶最高,石果红山茶最低;普通油茶净光合速率最高,是其它10个茶属植物种的124%~496%;11个山茶属植物叶片C含量在47.72%~53.07%之间,叶片N、P含量分别以攸县油茶和普通油茶最高,各物种叶片K含量差异不大;叶片δ13C与C和大量元素含量、光合速率均呈负相关关系,其中与N、P含量以及胞间CO2浓度呈极显著负相关,与水分利用效率呈正相关;δ15N与N、P含量显著正相关,与K含量显著负相关,与光合参数呈正相关,与水分利用效率呈负相关。 相似文献
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《广西林业科学》2015,(4)
以5年生岑溪软枝油茶(Camellia oleifera)林为研究对象,研究不同肥料养分配比对油茶叶片营养和叶绿素等生理指标的影响。结果显示,与对照对比,不同肥料养分配比油茶叶片营养元素含量均有所提高,按大小排列依次为F3(N∶P2O5∶K2O为16∶6∶8)F2(N∶P2O5∶K2O为15∶7∶8)F1(N∶P2O5∶K2O为14∶7∶9);就生理指标而言,与对照相比,不同肥料养分配比处理油茶叶片叶绿素a+b、硝酸还原酶活性和过氧化物酶活性变化的幅度分别为1.19%~11.90%、9.92%~43.65%、-8.05%~42.95%;处理F3(N∶P2O5∶K2O为16∶6∶8)在提高叶片营养和生理特性方面效果最佳。 相似文献
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油茶林果实成熟期养分分配特征 总被引：1，自引：0，他引：1
以常宁市10年生油茶作为试材,对油茶养分分配规律、油茶林土壤养分与树体各器官营养元素含量的相关性进行研究,旨在为油茶营养诊断以及配方施肥提供科学依据。结果表明:油茶各器官中,大量元素含量由高到低排序依次为N、Ca、K、Mg、P,微量元素含量由高到低排序依次为Mn、Fe、Pb、Zn、Cu、Cd;土壤大量元素含量由高到低排序依次为Ca、N、K、P、Mg,微量元素含量由高到低排序依次为Fe、Pb、Zn、Cu、Mn、Cd。土壤养分含量与油茶各器官养分指标具有不同程度的相关性,与油茶干的养分含量相关性最为紧密;土壤N、Zn、Mn、Pb、K含量与油茶植株养分元素含量的关系最为紧密;土壤Mn与油茶各器官Mn元素含量均呈现正相关;土壤N与油茶干中N含量呈现极显著相关;土壤Cd元素含量和油茶各器官中Cd元素含量多存在负相关性。 相似文献
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作为环境因子,风与树木的关系较其他因子复杂,树木对风胁迫的响应与适应是植物逆境生理生态学研究的热点和难点。本文综述了不同叶形树种叶片气体交换对风胁迫的响应差异,总结发现风对不同叶形树种叶片气体交换影响的研究结论差异较大,有的甚至截然相反,表明了不同叶形树种叶片气体交换对风胁迫响应的复杂性。同时分析了由叶形引起的微环境、边界层导度和理化特征对叶片气孔交换的影响。 相似文献
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Distribution of leaf nitrogen with respect to leaf mass per unit area (M(a)), nitrogen per unit mass (N(m)) and nitrogen per unit area (N(a)) within peach (Prunus persica L.) tree canopies was studied in two field experiments. In one experiment, leaf light exposure and M(a) were measured on leaves from different canopy positions of peach trees subjected to five nitrogen (N) fertilization treatments. Leaf light exposure and M(a) were linearly related and the relationship was independent of N fertilization. In a subsequent experiment, N fertilizer was applied to previously unfertilized trees in midsummer, after shoot growth had terminated. Application of N fertilizer did not affect mean canopy M(a). Fertilization increased N(m) of all leaves throughout the canopy compared with non-fertilized trees. No significant relationship between N(m) and M(a) was found in either fertilized or control trees. There was a linear relationship between N(a) and M(a) and the slope of the relationship was increased by N fertilizer application. We conclude that distribution of N(a) in peach tree canopies is primarily a function of M(a) partitioning with light and N(m), which is related to soil N availability. 相似文献
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《Fitoterapia》1999,70(1):25-31
The methanol extract of the leaves of Psidium guajava was found to inhibit paw oedema induced by carrageenan in rats and pain induced by acetic acid in mice, and exhibited an antipyretic effect. Oral administration of the extract reduced intestinal transit time and prevented castor oil-induced diarrhoea in mice. A CNS depressant activity was exhibited by the extract by potentiating the phenobarbitone sleeping time in mice. 相似文献
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Association of Eucalyptus globulus leaf anatomy with susceptibility to Teratosphaeria leaf disease 
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下载免费PDF全文 Resistance of Eucalyptus globulus juvenile foliage to Teratosphaeria leaf disease (TLD) damage has been shown to be under genetic control. Constitutive traits of juvenile leaves such as stomatal density (counted with wax on and with wax removed), total phenolics, total leaf wax, leaf mass per area (LMA) and leaf anatomical features were assessed to determine differences between pairs of resistant and susceptible families. Anatomic features assessed included cuticle, epidermis, palisade spongy mesophyll and total leaf thickness, as well as palisade cell size, shape and intercellular airspace. One interprovenance, one intraprovenance and two within‐family contrasts were used to compare resistant and susceptible pairs of families of Australian origin. The more resistant families had a significantly higher LMA and smaller percentage airspace compared with susceptible families. It is argued that one of the mechanisms by which E. globulus resists TLD involves the closely packed palisade mesophyll cells that increases LMA and reduces airspace, thereby restricting pathogen spread once infection has occurred. 相似文献
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《Forest Ecology and Management》1997,97(3):277-282
We compared leaf area index (LAI) estimates of a broad-leaf tropical hardwood, Metrosideros polymorpha Gaud (‘Ōhi’a), using a optical method (LI-COR LAI-2000) and direct determination (harvest and allometry). There was a strong correlation between LAI estimates by the two methods, but direct estimates were higher than the optical estimates by a factor of 2.44. The ratio of harvest leaf area to projected leaf area within twigs was similar (2.42) to that of whole plots, suggesting that aggregation of leaves at this scale of branching may account for most of the underestimate by the optical method. The within-branch ratio of actual to projected leaf area did not differ among three sites on three islands of varying land surface age but similar climate, suggesting that a correction factor determined by harvest could be used to adjust optical estimates of LAI in other M. polymorpha forests. 相似文献
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Foliage growth, mass- and area-based leaf nitrogen concentrations (Nm and N a) and specific leaf area (SLA) were surveyed during a complete vegetation cycle for two co-occurring savanna tree species: Crossopteryx febrifuga (Afzel. ex G. Don) Benth. and Cussonia arborea A. Rich. The study was conducted in the natural reserve of Lamto, Ivory Coast, on isolated and clumped trees. Leaf flush occurred before the beginning of the rainy season. Maximum leaf area index (LAI), computed on a projected canopy basis for individual trees, was similar (mean of about 4) for both species. Seasonal courses of the ratio of actual to maximum LAI were similar for individuals of the same species, but differed between species. For C. febrifuga, clumped trees reached their maximum LAI before isolated trees. The LAI of C. arborea trees did not differ between clumped and isolated individuals, but maximum LAI was reached about 2 months later than for C. febrifuga. Leaf fall was associated with decreasing soil water content for C. arborea. For C. febrifuga, leaf fall started before the end of the rainy period and was independent of changes in soil water content. These features lead to a partial niche separation in time for light resource acquisition between the two species. Although Nm, N a and SLA decreased with time, SLA and N a decreased later in the vegetation cycle for C. arborea than for C. febrifuga. For both species, N a decreased and SLA increased with decreasing leaf irradiance within the canopy, although effects of light on leaf characteristics did not differ between isolated and clumped trees. Given relationships between N a and photosynthetic capacities previously reported for these species, our results show that C. arborea exhibits higher photosynthetic capacity than C. febrifuga during most of the vegetation cycle and at all irradiances. 相似文献
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The relationship of branch cross sectional area (CS) to leaf biomass (LM) and leaf area (LA) was studied in three agroforestry tree species,Calliandra calothyrsus Maissn.,Erythrina berteroana Urban andErythrina poeppigiana (Walpers) O.F. Cook, to develop a non-destructive method for the estimation of LM and LA for trees managed with periodic pruning. Variation in these relationships was observed according to the bifurcation level and, in theErythrina spp., by clone. All the relationships were linear except the CS-LM relation in small branches ofE. poeppigiana, where it was initially exponential. At main branch level the relationship of CS to LM and LA was linear in all cases but the regression parameter values varied between species and clones, with determination coefficient (R2) 0.88–0.99. It was concluded that the ratio of main branch CS to LM and LA can be used for non-destructive estimation of the latter variables. The method has the additional benefit that the regression parameter value reflects the allocation of dry matter within a tree and, consequently, may give indications about its possible uses in different agroforestry systems.Work carried out at the Centro Agronómico Tropical de Investigación y Enseñanza (CATIE), Turrialba, Costa Rica. 相似文献