توجه: محتویات این صفحه به صورت خودکار پردازش شده و مقاله‌های نویسندگانی با تشابه اسمی، همگی در بخش یکسان نمایش داده می‌شوند.
۱Influence of Alnus subcordata, Populus deltoides and Taxodium distichum on Poor Drainage Soil, Northern Iran
اطلاعات انتشار: ECOPERSIA، دورهجدید،اول،شماره۳، Summer۲۰۱۳، سال
تعداد صفحات: ۱۲
This study was conducted to choose the best species for plantation on a poor drainage soil in southern coast of Caspian Sea, Iran. Nutrient concentrations in live and senescent leaves and soil properties were compared among Alnus subcordata C.A.Mey (N–fixing tree), Populus deltoides­ Marsh. (Non N–fixing tree)and Taxodium distichum (L.) Rich. (Coniferous tree) plantations. In each of these plantations and an adjacent natural forest, six 20×20m plots have been selected according to a 100m × 100m randomly systematic grid. Leaf samples of green trees were collected from the bottom one–third of the tree crown by clipping two small twigs located on opposite sides of the crown (six representative trees were sampled in each plot). Senescence leaves have been collected inside wooden trap–based in each stand. Results revealed different effects of species on soil nutrients. Alnus subcordata increased soil N (%) whereas Populus deltoides­ and Taxodium distichum reduced it.The results of nutrition, litter quality, retranslocation and soil properties indicated that Alnus improve soil quality in comparison with the two others. Keywords

۲Effect of Superabsorbent Polymer Aquasorb on Chlorophyll, Antioxidant Enzymes and Some Growth Characteristics of Acacia Victoriae Seedlings under Drought Stress
نویسنده(ها): ، ،
اطلاعات انتشار: ECOPERSIA، دوم،شماره۲، Spring ۲۰۱۴، سال
تعداد صفحات: ۱۳
To investigate the effect of droughtstress on chlorophyll content, enzymatic responses and some growth characteristics of Acacia victoriae seedlings and the effect of super–absorbent polymers (SAP) in reducing drought stress, a split plot experiment based on the completely randomized design was conducted. The treatments included four levels of drought stress (15, 30, 60 and 100% of field capacity) and four levels of SAP (0, 0.2, 0.4 and 0.6% weight percentages). The results of ANOVA showed a significant effect of drought stress on all growth characters, chlorophyll content and catalase and peroxidase enzymes activity, while the SAP didn''t show any significant effect on the weight and areas of the leaves. The interaction effect between drought stress and SAP on the weight, number of leaves, proportion of root dry weight to aerial organs, chlorophyll and peroxidase enzyme activity was also significant. The effect of drought stress on reducing the number of the leaves, leaf area, length, volume and surface of roots and also increasing the root dry weight to aerial organs dry weight ratio, amount of chlorophyll and activity of antioxidant enzymes was significant. The different levels of SAP could absorb and hold water and consequently reduce the effect of drought stress and improve the growth characteristics and reduce the activity of catalase and peroxidase enzymes.

۳Litter Production Dynamic in relation to Climatic Factors in Tree Plantations
اطلاعات انتشار: Journal of Environmental Resources Research، دوم،شماره۱، ۲۰۱۴، سال
تعداد صفحات: ۱۰
We studied litterfall dynamic of tree plantations in Dez River floodplain, at 14 to 15 years old. The plantations consist of Populus euphratica Oliv., Eucalyptus camaldulensis Dehnh., E. microtheca F. Muell, Acacia farnesiana (L.) Willd., A. salicina Lindl., A. saligna (Labill.) H. Wendl., A. stenophylla Benth. and Dalbergia sissoo Roxb. Litterfall was different between the tree species, and leaf litter fall was the dominant part, while reproductive and woody parts have considerable amounts in some species. The results also showed that most of the everegreen and deciduous trees litterfall were in Jun and October, respectively. Day length and maximum and minimum temperature controlled the litterfall of some species. Totally we could state that although leaf litter is the most part of litterfall, reproductive and woody parts have also considerable amounts in some species e.g. woody parts in Eucalyptus species. Also the obvious differences of litterfall fractions between the different species confirmed that the litterfall fractions should be considered in studying nutrient cycling.
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