Depczynski Martial, Fulton Christopher J, Marnane Michael J, Bellwood David R
ARC Centre of Excellence for Coral Reef Studies, School of Marine Biology, James Cook University, Townsville 4811, Australia.
Oecologia. 2007 Aug;153(1):111-20. doi: 10.1007/s00442-007-0714-2. Epub 2007 Apr 14.
Although critically important, the link between animal life histories and ecosystem energetics is seldom explored. In the pursuit of ecological simplification, ecosystem properties are typically described by models based on static counts, where organisms are aggregated into trophic- or size-based groups. Consequently, output is often based on an assumption that larger group biomass equals greater energetic contribution. Here, we modelled the individual growth of over 58,000 fishes from 74 genera within a coral reef ecosystem to investigate the role and importance of taxon-specific life histories to the division, spatial distribution and relative contribution of biomass production within 14 coral reef fish families. Rank changes among families in standing biomass to biomass production indicated that small cryptic families (e.g. Gobiidae and Blenniidae) exhibit collective growth potentials equal to or exceeding those of many other common families composed of individuals with body-sizes 1-3 orders of magnitude larger. Remaining at high risk of predation throughout their lives as a consequence of their small size, these cryptic fishes also provide a constant food resource and supply of reproductive energy to coral reefs throughout the year. Enhanced further by the strength and diversity of their trophic relationships within food webs, the highly productive nature of these small cryptic fishes suggests they make a substantial contribution to the flow of energy in coral reef ecosystems via predatory pathways. It appears that life histories leave a strong imprint on ecosystem energy fluxes and illustrate the importance of incorporating taxon-specific features when assigning values to key ecosystem processes.
尽管至关重要,但动物生活史与生态系统能量学之间的联系却很少被探讨。在追求生态简化的过程中,生态系统属性通常由基于静态计数的模型来描述,其中生物被聚集到基于营养级或大小的组中。因此,产出往往基于这样一种假设,即更大的群体生物量等于更大的能量贡献。在这里,我们对珊瑚礁生态系统中74个属的58000多条鱼类的个体生长进行了建模,以研究特定分类群生活史对14个珊瑚礁鱼类科内生物量生产的划分、空间分布和相对贡献的作用及重要性。各家族在现存生物量与生物量生产方面的排名变化表明,小型隐蔽性家族(如虾虎鱼科和鳚科)展现出的集体生长潜力等于或超过许多其他常见家族,而这些常见家族由体型大1至3个数量级的个体组成。由于体型小,这些隐蔽性鱼类一生都面临着很高的被捕食风险,它们也为珊瑚礁全年提供了持续的食物资源和繁殖能量供应。通过食物网中营养关系的强度和多样性的进一步增强,这些小型隐蔽性鱼类的高生产力特性表明它们通过捕食途径对珊瑚礁生态系统的能量流动做出了重大贡献。看来生活史在生态系统能量通量上留下了深刻印记,并说明了在为关键生态系统过程赋值时纳入特定分类群特征的重要性。