Hutchins Harry E, Hutchins Susan A, Liu Bo-Wen
Forestry Department, Itasca Community College, 55744, Grand Rapids, MN, USA.
Biology Department, Itasca Community College, 55744, Grand Rapids, MN, USA.
Oecologia. 1996 Mar;107(1):120-130. doi: 10.1007/BF00582242.
This study examined the interrelationships of the fall seed-foraging guild with Korean pine (Pinus koraiensis) and its regeneration. The study took place in old-growth and secondary-growth forests in Northeastern China. Foraging behavior, seed transportation distance, and cache location of various birds and mammals were observed. Regeneration characteristics of Korean pine were also analyzed using plots in various vegetation cover types, successional stages, and topographical situations. Ten species of vertebrates were able to harvest seed from the closed-cone Korean pine. Of these, the Eurasian nutcracker, Eurasian nuthatch, red squirrel, and Siberian chipmunk were found to be potential seed dispersal agents. The nutcracker was the most important dispersal agent, easily acquiring seed with its large pointed bill, carrying up to 62 seeds in one trip, carrying seed at least 4 km, and placing seed in a variety of sites 2.5-3 cm deep in the soil. The Eurasian nuthatch carried a single seed per trip at distances less than 50 m, needed nutcrackers to open the cones and expose seed before they could acquire seed, and occasionally cached seed in the soil. Red squirrels were uncommon visitors to the tree tops of Korean pine, carried cones shorter distances than nutcrackers, and were only found under forest canopies. Human harvest of cones by knocking off branches also affected squirrel behavior and reduced future cone crops. Siberian chipmunks also collected seed from cones in trees and appeared to transport seed less than 50 m. Six other species were observed in this study successfully harvesting seed from cones but were not potential seed dispersers. Natural seedling establishment was found to be over 1000 seedlings/ha except on old-growth pine-hardwood sites. Squirrels were commonest here, but few seedlings survived past the 2nd year due to the intense shading. Second-growth forest types, including aPicea plantation where nutcrackers cached seed daily, and an old-growth pine-hardwood selective-harvest site, had the greatest regeneration. In conclusion, most natural regeneration of Korean pine in this part of its range is due primarily to the Eurasian nutcracker. Nutcrackers can aid forest managers in reaching desired stocking levels after disturbance, as well as a more natural-appearing forest. Squirrels, chipmunks, and nuthatches are minor seedling establishment agents. Korean pine seed is an important food source used by at least 22 species of forest wildlife.
本研究调查了秋季种子觅食类群与红松（Pinus koraiensis）及其更新之间的相互关系。研究在中国东北的原始林和次生林中进行。观察了各种鸟类和哺乳动物的觅食行为、种子传播距离和贮藏位置。还利用不同植被覆盖类型、演替阶段和地形条件下的样地分析了红松的更新特征。有10种脊椎动物能够从紧闭球果的红松上获取种子。其中，发现坚果雀、坚果啄木鸟、松鼠和花鼠是潜在的种子传播者。坚果雀是最重要的传播者，它能用又大又尖的喙轻松获取种子，一次能携带多达62粒种子，传播距离至少4公里，并将种子贮藏在土壤中2.5 - 3厘米深的不同位置。坚果啄木鸟每次携带一粒种子，传播距离小于50米，需要坚果雀打开球果并露出种子后才能获取，偶尔也会将种子贮藏在土壤中。松鼠很少出现在红松的树冠上，携带球果的距离比坚果雀短，且只在森林树冠下被发现。人类通过敲打树枝采集球果的行为也影响了松鼠的行为，并减少了未来的球果产量。花鼠也从树上的球果中采集种子，其传播种子的距离似乎小于50米。在本研究中还观察到其他6种动物成功地从球果中获取了种子，但它们不是潜在的种子传播者。除了在原始松 - 硬木林地上，天然幼苗的更新密度超过1000株/公顷。松鼠在这里最为常见，但由于强烈的遮荫，很少有幼苗能存活到第二年。次生林类型，包括坚果雀每天贮藏种子的云杉人工林，以及原始松 - 硬木择伐林地，具有最强的更新能力。总之，在红松分布的这一区域，其大部分天然更新主要归功于坚果雀。坚果雀有助于森林管理者在干扰后达到期望的蓄积水平，并营造出更具自然风貌的森林。松鼠、花鼠和坚果啄木鸟是次要的幼苗更新促进者。红松种子是至少22种森林野生动物的重要食物来源。
