Conservation ecology for coastal Persea thunbergii forests at northern limit

我研究了在森林中的珍珠茅的发芽物候在北方限制，并进行了发芽实验，在苗圃使用完整的肉质果实和种子与纸浆删除。在一个封闭的树冠下，很少有幼苗出现在秋季后不久，他们的传播，大多数幼苗出现在第二年的夏天。相比之下，在森林边缘，许多幼苗出现在秋季以及在接下来的夏天。20%的去果肉种子在播种后不久的秋天发芽，尽管大多数果肉完整的种子在第二年的夏天发芽。食果鸟类通过吞食除去种子中的果肉，并将种子散布。食果动物的去髓可能导致了雷柏种子萌发的二型性。70%的秋季出苗幼苗在第二年冬天或早春死亡。而在30%的相对光通量密度下，秋季挺水幼苗的生长速度明显快于夏季挺水幼苗。在北方界限不可预测的冬季气候中，发芽二型性可能对幼苗存活很重要。

I examined the germination phenology of Persea thunbergii in the forest at the northern limit and conducted a germination experiment in a nursery using intact fleshy fruits and seeds with the pulp removed. Under a closed canopy of P. thunbergii, few seedlings emerged in autumn soon after their dispersal; most seedlings emerged in the following summer. In contrast, at the forest edges, many seedlings emerged in autumn as well as during the following summer. Twenty percent of the depulped seeds germinated in the autumn soon after sowing, although most of the seeds with pulp intact germinated during the following summer. Frugivorous birds remove the pulp from the seed by ingestion and scatter the seeds. Pulp removal by frugivores probably induces germination dimorphism of P. thunbergii. Seventy percent of autumn emergent seedlings died back the following winter or in early spring. However, the autumn emergent seedlings that escaped from dying back grew significantly faster than the summer emergent seedlings under a 30% relative photon flux density. Germination dimorphism may be important for seedling survival in the unpredictable winter climate at the northern limit.