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Plastic Responses in Tree Architecture to Different Light Intensity Habitats : A Case of Chinese Cork Oak

Hu X., Zhang W., Zhou J.

Polish Journal of Ecology

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2016

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Vol. 64, nr 4

500--508

EN

The capacity of plants to occupy different habitats is made possible by the plastic responses of their presenting in heterogeneous habitats. Light directly influences the plastic responses of plant architectural traits. We measured five years-old saplings of Chinese cork oak growing in different light intensity habitats (forest edge, forest gap and understory). A suite of architectural and leaf morphological attributes indicated a pronounced ability of Chinese cork oak to adapt to shade. Under low light intensity habitats, Chinese cork oak had a significant tendency to invest more in crown growth, characterized by the highest crown area, the lowest crown length ratio and the largest angle of the inclination of the main stem to the vertical. It expressed marked plagiotropic growth in shade indicating a horizontal light-foraging strategy. In addition, Chinese cork oak significantly exhibited the highest specific leaf area and the lowest total leaf area under low light intensity habitats. In shade, they showed some plasticity in displaying most of their leaf area at the top of the crown to minimize self-shading and to enhance light interception. This differentiation can be defined as a plastic phenomenon, likely related to the higher efficiency of light interception and absorption by saplings.

2

The Ecological Amplitude of Acorus calamus Young Shoots Under Water Level Gradient

Cao Y., Guo Z., Yang Y., Wang G., Xie Z.

Polish Journal of Ecology

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2015

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Vol. 63, nr 4

585--592

EN

This paper analysed the influence of the gradient of water levels (-54–120 cm) on Acorus calamus (A. calamus) young shoots in terms of their growth characteristics (germination rate, basal stem, height and biomass), leaf characteristics (number, area and moisture content), chlorophyll (chl) fluorescence parameters (Fv/ Fm, ETR, qP and qN) and other indicators. Based on a Gaussian model, we determined and quantified the response relationship between A. calamus young shoots and water level. The results showed that the ecological amplitude of water level for A. calamus young shoots was -52.3−141.8 cm, and the optimum range was -3.5−69.3 cm; a variety of indicators suggested that the optimum depth for A. calamus young shoots was from18.8 cm to 49.6 cm. The A. calamus seedling growth characteristics which were sensitive to changes in the water level were the germination rate and biomass. The germination rate was more sensitive to the submergence water depth, but the biomass was obviously influenced by the groundwater depth. Therefore, the A. calamus could be a suitable species for ecological restoration of land/inland water ecotones in lakes, rivers and reservoirs.

3

Leaf morphology shift of three dominant species along altitudinal gradient in an alpine meadow of the Quinghai â Tibetan Plateau

Zhong M., Wang J., Liu K., Wu R., Liu Y., Wei X., Pan D., Shao X.

Polish Journal of Ecology

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2014

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Vol. 62, nr 4

639--648

EN

It has been observed that leaf morphology shift within species is linked to climate change, but there are few studies on the effects of altitude change on leaf morphology of species. We hypothesized that similar to climate change, a morphological shift within species would occur over time under different growing altitudes. In this study, we evaluated three dominant grass species: Elymus nutans Griseb., Kobresia capillifolia Clarke., Carex moorcroftii Boott., taking advantage of the altitudinal variations (3000-4000 a.s.l.) on the Qinghai-Tibetan Plateau. Our study showed that almost all leaf traits of these three species had significant differences (P <0.05) across an altitudinal gradient. Different species responded differently to altitude change. Leaf thickness (LT) of the three species increased with increase in altitude. Leaf area (LA) of E. nutans and C. moorcroftii decreased with increasing altitude, but that of K. capillifolia increased. There was no obvious linear effect on leaf dry matter content (LDMC) and specific leaf area (SLA) of these three species. LDMC of E. nutans and C. moorcroftii showed a trend of increase, while that of K. capillifolia decreased. SLA of E. nutans and K. capillifolia showed a trend of increase, but that of C. moorcroftii decreased with increase in altitude. In addition, soil pH (pH) and air temperature (AT) decreased with increase in altitude. However, other soil and climate factors increased as altitude increased. The finding of this work is that leaf morphology shift within species happens under altitude change to adapt to specific environment.

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Inter and intra population variation of leaf morphological traits in natural stands of Buxus hyrcana (Pojark.) in Caspian Forests (Iran)

Yosefzadeh H., Tabari M., Espahbodi K., Jalali G., Bussotti F., Abdi E.

Polish Journal of Ecology

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2009

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Vol. 57, nr 2

291-301

EN

The leaf morphology of Buxus hyrcana (Pojark.), shade-tolerant and evergreen species growing in understorey of Caspian Forest was studied in five natural Iranian populations in order to recognize the pattern of within- and among-population variation of selected leaf morphological traits. Fifteen traits were selected and measured or calculated - list in Appendix. Leaves were collected from different geographical (between 36[degree]13'N and 53[degree]15'E) populations of B. hyrcana growing in the Caspian Forests located in Mazandaran Province (northern Iran) in the similar vegetation and site conditions but on different altitudes. Ten mature trees from five relatively small areas (0.5-1 ha) were selected in June. Then ANOVA model was used with both crossed and nested effects. The results showed that variation among the populations was significant in 13 of 15 traits (P <0.05); variation among the trees in the population was significant in 14 of 15 traits (P <0.05). Among all characters measured, the greatest plasticity was found for weight, leaf area mass and specific leaf mass. Function 1 explained 30% of the total variance and Function 2 represented another 17% of the total variance. PCA analysis showed that the most important role in function 1 allocated to width of lamina and leaf figure ratio (length of lamina/width of lamina) and in function 2 to top of leaf figure (width of lamina in 0.1 its length/width of lamina). The results of the average linkage clustering method evidenced four distinct clusters. Generally, morphological traits of leaves of B. hyrcana showed low variation among the considered populations based on clustering analysis, although some trees inside the population showed significantly different values in comparison with other trees.