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对不同生长阶段的长林53品系油茶,采用L27(313)正交试验设计,分别喷施不同浓度的生长素(IAA)、赤霉素(GA)、细胞分裂素(CTK)和芸苔素内酯(BRs),研究植物激素对油茶生长的影响。结果表明:①IAA是影响产量和叶片相对叶绿素含量的关键因子,GA是影响叶片钾含量的关键因子,IAA与GA交互作用是影响籽出仁率和仁出油率的关键因子,影响花提前开放的关键因子是GA和CTK互作,IAA、GA和CTK互作是影响干物质积累的关键因子,IAA和BRs是影响叶片磷的关键因子,CTK和BRs互作是影响叶片含氮关键因子;②在5月和10月喷施10 mg/L IAA、10 mg/L GA、10 mg/L CTK和0.001 mg/L BRs,长林53号油茶最早开花;5月和9月喷施10 mg/L IAA、0.1 mg/L GA、0.1 mg/L CTK和0.001mg/L BRs,叶片SPAD值最高;5月和9月喷施0.1 mg/L IAA、0.1 mg/L GA、10 mg/L CTK和0.001 mg/L BRs,有最高的干物质积累;5月和10月喷施1 mg/L IAA、1 mg/L GA、10 mg/L CTK和0.0... 相似文献
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Potential role of soil calcium in recovery of paper birch following ice storm injury in Vermont, USA
Joshua M. Halman Paul G. SchabergGary J. Hawley Christopher F. Hansen 《Forest Ecology and Management》2011,261(9):1539-1545
In recent years, an increased number of mature paper birch (Betula papyrifera Marsh.) and heart-leafed paper birch (B. papyrifera var. cordifolia (Regel) Fern.) in northeastern United States forests have exhibited decline symptoms including foliar loss, reduced fine branching, and tree mortality. We assessed crown health, radial growth, and available soil cations in 2006 as a preliminary assessment of factors that may be influencing paper birch decline. Tree rings began to decrease in width in 1998—the year of a severe region-wide ice storm. All trees (regardless of their current decline status) experienced reduced growth starting in 1998 and tree growth continued to decrease for two years following the ice storm. After this generalized growth decrease, trees that now have vigorous crowns showed a marked increase in growth, whereas trees that now have low crown vigor did not rebound in growth, but instead exhibited a significantly higher incidence of locally absent annual rings. Extractable soil-aluminum (Al), a phytotoxic element mobilized by acid deposition, was significantly higher in soils associated with declining trees compared to those adjacent to vigorous trees. Higher soil calcium (Ca) availability was associated with both vigorous crowns and increased radial growth following the 1998 ice storm. Furthermore, increased soil Ca availability was negatively correlated to the percentage of declining trees, and positively related to increased radial growth, whereas elevation was not significantly associated with either parameter. Although previously overlooked as a factor influencing paper birch recovery from injury, we found that available soil Ca was linked to crown vigor and rebounds in growth following an inciting event. 相似文献
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Katherine D. Heineman Ethan JensenAutumn Shapland Brett BogenriefSylvester Tan Richard RebarberSabrina E. Russo 《Forest Ecology and Management》2011,261(11):1820-1832
Tree height and crown allometries reflect adaptations for resource acquisition and structural stability, as well as plastic responses to a heterogeneous environment. While both light and soil resources limit growth and influence competitive responses in tropical forests, the effects of belowground resources on allometries are less understood, especially within the understory. To characterize outcomes of tree competition along an edaphic resource gradient, we quantified variation in height and crown allometries of six Bornean tree species from contrasting regeneration niches (light-demanding vs. shade-tolerant) on two soil habitats (clay-fine loam and sandy loam) within a 52-ha forest dynamics plot. Using empirically-fit allometric parameters and diameter growth rates from plot census data, we modeled tree height and crown area growth over the projected life span of each species. Based on resource competition theory, we hypothesized that tree species specializing on and populations of generalist species growing on the relatively moister, more fertile clay-fine loam soil habitat would have faster height and crown growth rates, compared to those on the sandy loam habitat, regardless of regeneration niche. Among soil specialists and within generalists of both genera, trees growing on clay-fine loam had taller stems and larger crowns at a given age and faster height and crown area growth rates at most sizes than trees on sandy loam. Differences in height and crown growth were driven by the faster diameter growth rates of trees on clay-fine loam, not by differences in height- and crown-diameter allometries, as trees on sandy loam were significantly taller at a given diameter, and differences in crown allometry were not consistent across soil habitats. Characterizing the height and crown growth responses of trees along resource gradients provides insight into the mechanisms that maintain diversity in tropical forests. Our results point to the importance of adaptive and plastic responses to both above and belowground resource availability in determining the allometric growth of trees and suggest that this diversity of responses may contribute tree species coexistence through competition-based trade-off mechanisms and variation in growth among individuals. Additionally, as the importance estimating natural carbon sequestration increases with the escalating effects of anthropogenic climate change, differences in tree growth and architecture across soil habitats also have implications for the approximation of forest carbon storage on heterogeneous tropical soils. 相似文献
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R. Picchio 《Forest Ecology and Management》2011,262(2):237-243
Damage to residual stand after partial harvesting or thinning may lead to serious economic losses in terms of both timber quality at the final harvest, and tree growth reduction. Logging damages and their effect on tree growth were studied in a long term experiment on Corsican pine in central Italy. Damage frequency, agent (felling, skidding), position (root damage, stem base, between 0.3 and 1 m a.g.l., >1 m a.g.l.) and severity (light, severe) and tree growth were measured after selective thinning from below and at 10 years after the treatment. In detail, we aimed at: monitoring mechanical damages to trees at the end of thinning and after 10 years; and assessing stand stability, growing stock, ring width and basal area at 10 years after the thinning. The thinning removed about 20% of volume, 38% of trees and 26% of basal area. The basal area decreased from 56 m2 ha−1 to 42 m2 ha−1 but after 10 years it increased again to 56 m2 ha−1. Immediately after thinning, 13.6% of the standing trees was damaged, out of these 36.17% showed severe injuries. Damages to standing trees were mainly due to skidding. Ten years after thinning, the percentage of damaged trees was about 17%, out of which 86.67% showed severe wounds. An increase of damaged trees and of trees with severe wounds was observed suggesting that a deeper knowledge on long-term effect of logging damages is needed. This study did not highlight any effect of logging damage on tree growth. In fact, no difference in ring width was recorded between damaged and undamaged trees. 相似文献