Species-richness patterns in space, depth, and time (1989-1999) of the Portuguese fauna sampled by bottom trawl
Species-richness patterns in space, depth, and time (1989-1999) of the Portuguese fauna sampled by bottom trawl
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通过底拖网取样的葡萄牙动物群在空间、深度和时间上的物种丰富度模式（1989-1999）
DOI：
10.1051/alr:2006009
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发表时间：
2006
影响因子：
1.1
通讯作者：
M. Gomes
中科院分区：
文献类型：
--
作者：
P. Sousa;M. Azevedo;M. Gomes
我们分析了 1989 至 1999 年间在葡萄牙陆架和上坡（97 个采样站网格，36−710 m）夏季、秋季和冬季进行的一系列 22 次底栖鱼类调查，以解决物种丰富度（物种数量）的纬度和深度趋势的假设，以及这些模式是否随时间和季节变化。丰富度是通过广义加性模型（GAM）来建模的，显着的协变量是纬度和经度、关节空间平滑度、深度、时间顺序和季节。当纬度升高时，沿着大陆边缘检测到丰富度下降，在北部浅海地区发现丰富度最低。因此，尽管我们的研究只跨越了大约5度的纬度，但我们没有发现生态学家普遍承认的赤道-极点纬度上丰富度下降的例外情况。关于海洋鱼类物种丰富度随深度变化的方式尚未达成共识，但我们的研究结果在整个十一年期间是一致的：丰富度随着深度的增加而略有下降，从海岸线到陆架断口（200−300 m），然后沿着斜坡稳定增加。纬度和深度的变化模式在时间和季节之间持续存在，但其幅度发生了变化。与其他季节相比，冬季的丰富度更高。
We have analyzed a series of 22 groundfish surveys conducted between 1989 and 1999 on the Portuguese shelf and upper slope (97 sampling station grid, 36−710 m) in the summer, autumn, and winter, to address the hy- potheses of latitudinal and depth trends in species richness (number of species) and whether these patterns changed over time and among seasons. Richness was modelled by means of a Generalized Additive Model (GAM) with signif- icant covariates being latitude and longitude, in a joint-spatial smooth, and depth, chronological time, and season. A decrease in richness was detected along the continental margin, when moving higher in latitude, with lowest richness being found in the shallow northern area. Thus, although our study spanned only about 5 degrees in latitude, we found no exception to the equator-pole latitudinal decrease in richness commonly acknowledged by ecologists. There is no common agreement on the way marine fish species richness varies with depth, yet our findings were consistent for the entire eleven-year period: richness decreases slightly with depth, from the coastline to the shelf break (200−300 m), steadily increasing afterwards down the slope. The patterns of change in latitude and depth persisted in time and among seasons but their magnitude changed. Richness was higher in the winter compared to the other seasons.