一些嚙齒類動物在取食植物種子的同時還對部分種子進行分散貯藏，這種行為對一些大粒種子植物的擴散至關(guān)重要,。種子的特征影響嚙齒類動物的喜好,，但由于自然界種子不同性狀特征鰲合在一起，要弄清楚哪種性狀影響嚙齒類動物的選擇行為實屬不易,。近日,，中科院西雙版納熱帶植物園博士研究生王博及其導師陳進研究員通過設計一種人工種子和一組試驗，巧妙地解決了上述難題,，該研究成果發(fā)表在國際權(quán)威雜志Ecology,。
該研究在云南西北部中甸高山植物園內(nèi)的一片天然松林里進行，研究人員用泥土做成種子形狀,，通過改變大小和人工種子的填充物比例來探討種子大小,、單寧含量以及營養(yǎng)成分對分散貯藏習性嚙齒類動物的影響。該森林內(nèi)進行種子分散埋藏的主要是二種姬鼠（Apodemus）,。研究結(jié)果表明,，姬鼠就地取食小種子，搬運埋藏中等大小的種子（直徑1.2—2.5cm）,，并且種子越大被搬運的距離越遠。種子的營養(yǎng)和單寧含量也同樣顯著影響嚙齒類動物的行為,，但這種影響在不同年份表現(xiàn)不一致,。嚙齒類動物也表現(xiàn)出一定程度的選擇多個性狀最優(yōu)的種子。但總體上看,，種子大小對這種具分散貯藏習性的嚙齒類動物在種子取食和散布的選擇中起決定性的作用,。該研究結(jié)果還提示喬木植物可以通過簡單地增大種子大小來提高種子的長距離散布能力。該人工種子研究系統(tǒng)還為今后進一步研究植物和嚙齒類動物的相互關(guān)系及協(xié)同進化提供方法上的借鑒,。（生物谷Bioon.com）
生物谷推薦原始出處：
Ecology: Vol. 90, No. 11, pp. 3023-3032. doi: 10.1890/08-2188.1
Seed size, more than nutrient or tannin content, affects seed caching behavior of a common genus of Old World rodents
Bo Wang1,2 and Jin Chen1,3
1CAS Key Laboratory of Tropical Forest Ecology, Xishuangbanna Tropical Botanical Garden, Chinese Academy of Sciences, Mengla, Yunnan Province 666303, China
2Graduate School of Chinese Academy of Sciences, Beijing 100049, China
Scatter-hoarding rodents play an important dispersal role for many large-seeded plants. Seed traits affect their foraging behavior; however, it is difficult to isolate their effects because of the covariance among traits. Here, we used artificial seeds to partition the effects of seed size, tannin content, and nutrient content on scatter-hoarding rodents in a natural pine forest in Northwest Yunnan, China. Apodemus, a common genus of Old World rodents, consistently consumed small seeds in situ but removed medium-sized seeds (1.2–2.5 cm in diameter) and transported bigger seeds farther. Seed nutrient and tannin contents also significantly influenced rodents' behavior, but response varied substantially between years. Rodent behavior did involve some aspects of multivariate optimization. Our results strongly indicate that seed size is a decisive factor for scatter-hoarding rodents in the choice between seed predation and dispersal, while nutrient and tannin content played a less consistent role, possibly responding to confounding factors in the community. This result also has important implications for seed production by trees, which can improve the probability of long-distance dispersal of high-quality offspring by simply making them larger. The ability to tease apart the relative influence of different seed traits on the behavior of predators provides powerful insight into this important coevolutionary dynamic.
