Phase shifts, alternative states, and the unprecedented convergence of two reef systems
Phase shifts, alternative states, and the unprecedented convergence of two reef systems
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DOI：
10.1890/03-0108
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发表时间：
2004-07-01
期刊：
影响因子：
4.8
通讯作者：
O'Neill, MW
中科院分区：
文献类型：
--
作者：
Aronson, RB;MacIntyre, IG;O'Neill, MW
初始条件可以在空间上分离的群落的生物组成中产生差异，但强烈的大规模扰动有可能减少或消除这些历史差异。后一种可能性对于珊瑚礁尤其令人关切，因为珊瑚礁在过去25-30年中发生了巨大变化。本文报道了一个案例，其中两个珊瑚礁系统与不同的生物历史最近扰动到一个单一的，新颖的state.We比较了千年尺度的记录，物种优势的珊瑚礁在巴伊亚阿尔米兰特，沿海泻湖在巴拿马西北部，以前发表的记录，从珊瑚礁在陆架泻湖的伯利兹。从巴伊亚阿尔米兰特在5-10的水深提取的珊瑚礁岩心显示，巴拿马珊瑚礁是持续不同的伯利兹珊瑚礁至少2000-3000年前的最后几十年。巴拿马的珊瑚礁一直由分支指状珊瑚，滨珊瑚属。（主要是P. furcata）。从Porites占主导地位的状态转变为其他珊瑚物种的主导地位是罕见的，仅限于小区域，并持续数十年至数百年。在同一时期，伯利兹珊瑚礁在同一深度范围内一直由鹿角珊瑚鹿角珊瑚（Acropora cervicornis）主导。从顶孔菌占主导地位的国家再次罕见和空间局部化。AC的人口。20世纪80年代后期爆发的一场白斑病几乎使伯利兹泻湖中的滨鹬灭绝，近几十年来，水质的变化显然对巴伊亚阿尔米兰特的滨鹬分支有害。这些大规模的扰动导致两个珊瑚礁系统聚集在第三个历史上前所未有的状态：莴苣珊瑚Agaricia tenuifolia的统治地位。AG. tenuifolia具有生活史属性和环境耐受性，使其能够在两个受干扰的生态系统中占主导地位。虽然这两个阶段转移到银。tenuifolia在一般机制和具体原因上都不同，它们具有消除巴拿马和伯利兹珊瑚礁之间底栖生物组成显著差异的作用。因此，物种组成的变化抹去了几千年珊瑚礁历史的影响。
Initial conditions can generate differences in the biotic composition of spatially disjunct communities, but intense, large-scale perturbations have the potential to reduce or eliminate those historical differences. The latter possibility is of particular concern with respect to coral reefs, which have undergone dramatic changes in the last 25-30 years. This paper reports a case in which two reef systems with different biotic histories were recently perturbed to a single, novel state.We compared millennial-scale records of species dominance from reefs in Bahia Almirante, a coastal lagoon in northwestern Panama, to previously published records from reefs in the shelf lagoon of Belize. Reef cores extracted from Bahia Almirante at 5-10 in water depth revealed that the Panamanian reefs were persistently dissimilar from the Belizean reefs for at least 2000-3000 years prior to the last several decades. The Panamanian reefs were dominated continuously by branching finger corals, Porites spp. (primarily P. furcata). Shifts from the Porites-dominated state to dominance by other coral species were rare, were restricted to small areas, and lasted for decades to centuries. The Belizean reefs were dominated continuously by the staghorn coral Acropora cervicornis in the same depth range during the same period. Excursions from the Acropora-dominated state were again rare and spatially localized. Populations of Ac. cervicornis in the Belizean lagoon were nearly extirpated by an outbreak of white-band disease in the late 1980s, and changes in water quality were apparently detrimental to branching Porites in Bahia Almirante in recent decades. These large-scale perturbations caused the two reef systems to converge on a third, historically unprecedented state: dominance by the lettuce coral Agaricia tenuifolia. Ag. tenuifolia possesses life-history attributes and environmental tolerances that enabled it to become dominant in both disturbed ecosystems. Although the two phase shifts to Ag. tenuifolia differed in both their general mechanisms and specific causes, they had the effect of eliminating the salient difference in benthic composition between the Panamanian and Belizean reefs. The changes in species composition thus obliterated the influence of several thousand years of reef history.