McWilliam Mike, Dornelas Maria, Álvarez-Noriega Mariana, Baird Andrew H, Connolly Sean R, Madin Joshua S
Hawai'i Institute of Marine Biology, University of Hawai'i at Mānoa, Kāne'ohe, Hawai'i, USA.
Centre for Biological Diversity, Scottish Oceans Institute, University of St Andrews, St Andrews, UK.
Ecology. 2023 Jan;104(1):e3863. doi: 10.1002/ecy.3863. Epub 2022 Nov 1.
Life-history traits are promising tools to predict species commonness and rarity because they influence a population's fitness in a given environment. Yet, species with similar traits can have vastly different abundances, challenging the prospect of robust trait-based predictions. Using long-term demographic monitoring, we show that coral populations with similar morphological and life-history traits show persistent (decade-long) differences in abundance. Morphological groups predicted species positions along two, well known life-history axes (the fast-slow continuum and size-specific fecundity). However, integral projection models revealed that density-independent population growth (λ) was more variable within morphological groups, and was consistently higher in dominant species relative to rare species. Within-group λ differences projected large abundance differences among similar species in short timeframes, and were generated by small but compounding variation in growth, survival, and reproduction. Our study shows that easily measured morphological traits predict demographic strategies, yet small life-history differences can accumulate into large differences in λ and abundance among similar species. Quantifying the net effects of multiple traits on population dynamics is therefore essential to anticipate species commonness and rarity.
生活史特征是预测物种常见性和稀有性的有效工具，因为它们会影响种群在特定环境中的适合度。然而，具有相似特征的物种可能具有截然不同的丰度，这对基于特征的可靠预测前景提出了挑战。通过长期的种群统计学监测，我们发现具有相似形态和生活史特征的珊瑚种群在丰度上存在持续（长达数十年）的差异。形态学组预测了物种在两个著名的生活史轴（快-慢连续统和特定大小的繁殖力）上的位置。然而，积分投影模型显示，形态学组内与密度无关的种群增长（λ）更具变异性，并且优势物种的λ始终高于稀有物种。组内λ的差异在短时间内预测了相似物种之间的丰度差异很大，并且是由生长、生存和繁殖方面的微小但累积的变化产生的。我们的研究表明，易于测量的形态学特征可以预测种群统计学策略，但微小的生活史差异可能会累积成相似物种在λ和丰度上的巨大差异。因此，量化多个特征对种群动态的净效应对于预测物种的常见性和稀有性至关重要。
