Net production rates and fruiting strategies of Alnus pendula and A. sieboldiana stands with special reference of pollen production

再生产器官的每个组成部分的净生产率和数量序列在花芽分化和种子差异在两个年轻的水平上研究了在Alnus sieboldiana （S stand）和A。pendula （P支架），xeric succession中的先驱者，具有硝基固定的能力。地面净生产率为2，100克/米^2·1987年和1988年的S站和1，200克/米^2。平均在P. Leaf生物量的S在峡谷关闭后到达高峰期，从而提高了净生产。在S和P上，固体土壤中的土壤缺口的生产率似乎比有机土壤上的决定性森林要大，而等同于Sugi和常青树的叶子。生产率的繁殖率包括生产率为50 - 130克/米^2·年，在任何种子中只占10%。重复剂成分生产中的种子的低分布在干燥物质中，对于重复剂战略的先驱来说是有利的。1986 - 1988年期间，没有明显的年度变化在S和P的数量序列中被识别，在种子生产中可能会受到微小的影响。波伦谷物的数量是种子形成所必需的，种子形成有500，000个，P有200，000个。在年轻的S支架上，70 - 80%的女性中风在皱纹前脱落。在成熟的P阶段，1986年和1988年水果摄入率为10%，而1987年的水果摄入率与降雨期的降雨量一样高，相当于45%。

Net production rates and number sequences of each component of the reproductive organ in steps between flower bud differentiation and seed dispersal were studied in two young stands of Alnus sieboldiana (S stand) and A. pendula (P stand), pioneer in xeric succession and with capability of nitrogen fixation. Above-ground net production rates were 2,100 g/M^2・yr in 1987 and 1988 for the S stand, and 1,200 g/M^2. yr in average between both the years for the P. Leaf biomass of the S was arrived at the peak after canopy closing, which raised the net production. Both the production rates in the S and P on a detrius lack in organic soils are considerably greater than that of deciduous forests on organic soils, and equal to that of Sugi and evergreen broadleaf ones. The production rates of the reproductive parts including pollen were 50 - 130 g/M^2・yr, in which seeds occupied only 10 %. The low distribution of seeds among dry-matter production of the repoductive components is profitable for the repoductive strategy of pioneer. No remarkable yearly changes during 1986 - 1988 were recognized in the number sequences in the S and P, which can be affected by small yearly ones of seeds production. The number of pollen grains neccessary for the formation of a seed was 500,000 in the S, and 200,000 in the P. In the young S stand, total female strobiles of 70 - 80% were fallen before ripe. In the mature P stand, fruit abscission percentages in 1986 and 1988 were 10%, while in 1987 that was as high as 45% due to the spell of rainy weather in flowering period.