Nutrient retranslocation in trees is important in nutrient budgets and energy flows in forest ecosystems. We investigated nutrient retranslocation in the fine roots of a Manchurian Ash （Fraxinus mandshurica） and a L...Nutrient retranslocation in trees is important in nutrient budgets and energy flows in forest ecosystems. We investigated nutrient retranslocation in the fine roots of a Manchurian Ash （Fraxinus mandshurica） and a Larch （Larix olgensis） plantation in northeastern China. Nutrient retranslocation in the fine roots was investigated using three methods, specifically, nutrient concentration, the ratio of Ca to other elements （Ca/other elements ratio） and nutrient content. The method based on nutrient content proved most suitable when investigating nutrient retranslocation from fine roots of the two species. The nutrient-content-based method showed that there were retranslocations of N, P, K and Mg from the fine roots of Manchurian Ash, with retranslocation efficiencies of 13, 25, 65, and 38 %, respectively, whereas there were no Ca retranslocations. There were retranslocations of N, P, K, Ca and Mg from the fine roots of Larch, with retranslocation efficiencies of 31, 40, 52, 23 and 25 %, respectively.展开更多
The spatial distribution of standing fine roots in tree rows of different species in a 12-year-old mixed stand of ash (Fraxinus mandshurica Rupr.) and larch (Larix olgensis Henry) was studied by soil core sampling in ...The spatial distribution of standing fine roots in tree rows of different species in a 12-year-old mixed stand of ash (Fraxinus mandshurica Rupr.) and larch (Larix olgensis Henry) was studied by soil core sampling in early spring, 2001. It is found that ash and larch differ greatly in their belowground biomass distribution. Ash has much higher fine root biomass density in the soil than larch at stand level (with the max value of 4442.3 vs. 2234.9 gm-3). Both tree species deployed more fine roots in their neighboring zone, suggesting a less intensive competition between roots of the two species. Both fine root biomass density and root length density of ash in the zone between larch tree rows are greater than that of larch in zone between ash tree rows, indicating that ash is more powerful than larch in belowground competition. The spatial distribution feature of roots favors the growth of ash in the mixed stand.展开更多
Horizontal and veftical distributions of fine root abundance (mass per unit ground surface arca) were investi-gated in a densely planted larch - ash -stripe - mixed tbrest on dark broxvn forest soil in northeast China...Horizontal and veftical distributions of fine root abundance (mass per unit ground surface arca) were investi-gated in a densely planted larch - ash -stripe - mixed tbrest on dark broxvn forest soil in northeast China. There was evidencefor some degree of below-ground niche partitioning (or differentiation) betmpen the two species in hoth the horizontal andvertical directions. The ash fine roots largely penetrated into the larch belt (larch Sub-community) in surttrce soil (0-20 cm),indicating a possible inductive effect of larch ecological field on ash roots, while the penetration of larch tine roots into ashbelt (ash sub-community) was much restricted- which reflected a negative influence of ash ccological tield on Iarch roots. Inthe vertical direction of marginal soil the ash tine roots were mainly distributed in topsoil with a vertical gradient similar tothat as in the internal ash sub-community. but the larch fine roots were relatively compelled to deepcr soil layers by the com-petition (or exclusion) of marginal ash trees. All the dit1brences or complemcntarity wcre considered to the result of inter-specitic competition, which was important to the coexistence of the two tbrest species and the sustainability of mixed planta-tion.展开更多
基金supported by the National Key Technology Research and Development Program(2012BAD21B0202-02)the Natural Science Foundation of Heilongjiang Province of China(C201340)the assisted project by Heilong Jiang Postdoctoral Funds for Scientific Research Initiation(LBH-Q13006)
文摘Nutrient retranslocation in trees is important in nutrient budgets and energy flows in forest ecosystems. We investigated nutrient retranslocation in the fine roots of a Manchurian Ash （Fraxinus mandshurica） and a Larch （Larix olgensis） plantation in northeastern China. Nutrient retranslocation in the fine roots was investigated using three methods, specifically, nutrient concentration, the ratio of Ca to other elements （Ca/other elements ratio） and nutrient content. The method based on nutrient content proved most suitable when investigating nutrient retranslocation from fine roots of the two species. The nutrient-content-based method showed that there were retranslocations of N, P, K and Mg from the fine roots of Manchurian Ash, with retranslocation efficiencies of 13, 25, 65, and 38 %, respectively, whereas there were no Ca retranslocations. There were retranslocations of N, P, K, Ca and Mg from the fine roots of Larch, with retranslocation efficiencies of 31, 40, 52, 23 and 25 %, respectively.
基金This study was supported by National Natural Science Foundation of China (Grant No. 30130160) and the Quick Response of Basic Research Supporting Program (Grant No.2102)
文摘The spatial distribution of standing fine roots in tree rows of different species in a 12-year-old mixed stand of ash (Fraxinus mandshurica Rupr.) and larch (Larix olgensis Henry) was studied by soil core sampling in early spring, 2001. It is found that ash and larch differ greatly in their belowground biomass distribution. Ash has much higher fine root biomass density in the soil than larch at stand level (with the max value of 4442.3 vs. 2234.9 gm-3). Both tree species deployed more fine roots in their neighboring zone, suggesting a less intensive competition between roots of the two species. Both fine root biomass density and root length density of ash in the zone between larch tree rows are greater than that of larch in zone between ash tree rows, indicating that ash is more powerful than larch in belowground competition. The spatial distribution feature of roots favors the growth of ash in the mixed stand.
文摘Horizontal and veftical distributions of fine root abundance (mass per unit ground surface arca) were investi-gated in a densely planted larch - ash -stripe - mixed tbrest on dark broxvn forest soil in northeast China. There was evidencefor some degree of below-ground niche partitioning (or differentiation) betmpen the two species in hoth the horizontal andvertical directions. The ash fine roots largely penetrated into the larch belt (larch Sub-community) in surttrce soil (0-20 cm),indicating a possible inductive effect of larch ecological field on ash roots, while the penetration of larch tine roots into ashbelt (ash sub-community) was much restricted- which reflected a negative influence of ash ccological tield on Iarch roots. Inthe vertical direction of marginal soil the ash tine roots were mainly distributed in topsoil with a vertical gradient similar tothat as in the internal ash sub-community. but the larch fine roots were relatively compelled to deepcr soil layers by the com-petition (or exclusion) of marginal ash trees. All the dit1brences or complemcntarity wcre considered to the result of inter-specitic competition, which was important to the coexistence of the two tbrest species and the sustainability of mixed planta-tion.
