Travis Joseph, Trexler Joel C
Department of Biological Science, Florida State University, 32306-2043, Tallahassee, FL, USA.
Oecologia. 1986 Apr;69(1):110-116. doi: 10.1007/BF00399045.
We designed a series of field experiments to investigate the importance of interactions between biotic and abiotic factors on the survival and development of larval cohorts of Bufo terrestris. Five "blocks" in a large pond represented environments of varying physical harshness. In the more severe blocks, increased density inhibited growth rates, yet in the more benign blocks, increased density enhanced growth rate. Although different blocks produced very different levels of survival to metamorphosis and size at metamorphosis, there were no interactions with density. Increased density produced lengthened development times in the harsher blocks, but had no effect in the less stressful blocks. Hatchlings that were in the lowest of 3 initial size classes never caught up with their larger contemporaries and survived poorly. Hatchlings in the middle and largest size classes performed equivalently in all parameters of growth and development, but hatchlings from the middle size class were less likely to survive than their larger contemporaries. The effects of initial size did not interact with block. The inhibitory patterns displayed by density in conjunction with varying physical environments are similar to those found in comparable experiments with plants.
我们设计了一系列野外实验，以研究生物和非生物因素之间的相互作用对北美蟾蜍幼体群体生存和发育的重要性。一个大池塘中的五个“区域”代表了不同物理严酷程度的环境。在较严酷的区域，密度增加会抑制生长速度，但在较温和的区域，密度增加会提高生长速度。尽管不同区域产生的变态存活率和变态时的大小差异很大，但与密度没有相互作用。在较严酷的区域，密度增加会延长发育时间，但在压力较小的区域则没有影响。处于最初三个大小等级中最小等级的幼体永远无法赶上较大的同龄幼体，且存活率很低。处于中等和最大大小等级的幼体在生长和发育的所有参数方面表现相当，但中等大小等级的幼体比其较大的同龄幼体存活的可能性更小。初始大小的影响与区域没有相互作用。密度与不同物理环境共同呈现的抑制模式与在植物的类似实验中发现的模式相似。
