Mark A F, Chapin F S
Department of Botany, University of Otago, P.O. Box 56, Dunedin, New Zealand.
Insitute of Aretic Biology, University of Alaska Fairbanks, 99775, Fairbanks, AK, USA.
Oecologia. 1989 Jan;78(1):27-34. doi: 10.1007/BF00377194.
The evergreen tussock-forming Eriophorum vaginatum revealed consistently earlier (c. 1 moth) phenology and greater biomass per tiller than the summergreen rhizomatous E. scheuchzeri in all four components measured (vegetative and reproductive shoots and stems) under the same climatic regime in central Alaska over one growing season. Greatest allocation to vegetative shoot growth occurred in mid-summer in both species. The tussock growth form of E. vaginatum raised shoot meristems 25-30 cm above the soil surface, where temperatures were warmer, permitting shoot growth to begin earlier in spring and continue longer in autumn than in E. scheuchzeri. Consequently, E. vaginatum was able to allocate reserves to reproductive tillers primarily in autumn and early spring, times when minimal reserves were required for vegetative growth. By contrast, the rhizomatous E. scheuchzeri had a more constrained growing season, and allocation to reproduction coincided with allocation to vegetative growth. For this reason, reserves were drawn down more fully in mid-summer in E. scheuchzeri than in E. vaginatum. The more conservative use of nutrient stores in E. vaginatum may relate to its great longevity, reduced allocation to reproduction (including low seedling recruitment), and relatively stable habitats. The mid-seasonal pulse of allocation to reproduction in E. scheuchzeri appears viable only in relatively fertile disturbed sites, where the soil nutrient supply is sufficient to support simultaneous allocation to vegetative growth and reproduction.
在阿拉斯加中部一个生长季节的相同气候条件下，形成常绿草丛的毛果苔草在所有四个测量组分（营养枝、生殖枝和茎）中，物候期始终比夏季生长的具根状茎的沼苔草早（约1个月），且每个分蘖的生物量更大。两个物种在仲夏时节对营养枝生长的分配量最大。毛果苔草的草丛生长形态使茎尖分生组织高出土壤表面25 - 30厘米，那里温度更高，这使得其茎在春季开始生长的时间比沼苔草更早，在秋季持续生长的时间也更长。因此，毛果苔草能够主要在秋季和早春将储备分配给生殖分蘖，而这两个时期营养生长所需的储备最少。相比之下，具根状茎的沼苔草生长季节更受限制，其对生殖的分配与营养生长的分配同时进行。因此，沼苔草在仲夏时节比毛果苔草更充分地消耗储备。毛果苔草对养分储备的更保守利用可能与其较长的寿命、对繁殖的分配减少（包括低幼苗补充率）以及相对稳定的栖息地有关。沼苔草在季节中期对繁殖的分配脉冲似乎仅在相对肥沃的干扰地点可行，在这些地点土壤养分供应足以支持同时对营养生长和繁殖的分配。
