Biogeography of the Lord Howe Rise region, Tasman Sea

In this review we aim to synthesise physical and biological information on the Lord Howe Rise (LHR) region to describe its biogeography at a regional scale (100s of kilometres) and assess this in a national and global context. The LHR region is large (1.95 million km2), spans tropical and cool temperate latitudes (18.4oS to 40.3oS), and is topographically complex being formed of large expanses of soft sediment basins and plateaus (i.e. subdued bathymetric features), with scattered seamounts, guyots, knolls, and pinnacles (i.e. raised bathymetric features). Physical factors can vary between these two broad feature types, particularly regarding depth and substrate, although no clear relationship was detected between sediment texture and geomorphic features across the survey area. Biological data from two recent surveys (TAN0713 and NORFANZ) show differences in assemblages and species distribution between raised and subdued bathymetric features and suggest that biological communities are indeed influenced by substrate as well as depth-related variables, with some taxa such as demersal fish showing latitudinal gradients. There are only limited spatially-replicated studies and no time-series data available for most of the LHR region, but paleo-environmental processes and examples from other regions provide some indication of migration, speciation, and endemism in the LHR region.

本综述旨在整合豪勋爵海隆（Lord Howe Rise, LHR）区域的物理与生物学数据，以刻画该区域在百公里尺度下的生物地理特征，并在国家及全球框架下对其进行评估。该区域总面积达195万平方千米，横跨热带与凉温带纬度区间（南纬18.4°至南纬40.3°），地形复杂，由大片软沉积盆地与高原（即缓起伏型水深地形特征（subdued bathymetric features））构成，同时散布着海山（seamounts）、平顶海山（guyots）、海丘（knolls）与尖锥海峰（pinnacles，即凸起型水深地形特征（raised bathymetric features））。这两类主要地形特征间的物理参数存在差异，尤以水深与底质类型最为显著；但在整个调查区域内，未发现沉积物粒度与地貌特征之间存在明确关联。两项近期调查（TAN0713与NORFANZ）获取的生物学数据显示，凸起型与缓起伏型水深地形间的生物群落组成与物种分布存在显著差异，表明生物群落确实受底质与水深相关变量的共同影响；部分类群（如底栖性鱼类（demersal fish））呈现出纬度梯度分布特征。豪勋爵海隆区域的大部分区域仅开展过少量空间重复研究，且无可用的时间序列数据；但古环境演化过程与其他区域的研究案例，为该区域的生物迁移、物种形成（speciation）与特有现象（endemism）提供了一定的佐证依据。