Jänes Holger, Herkül Kristjan, Kotta Jonne
School of Life and Environmental Sciences, Centre for Integrative Ecology, Deakin University, Victoria 3125, Australia.
Estonian Marine Institute, University of Tartu, Mäealuse 14, 12618 Tallinn, Estonia.
Mar Environ Res. 2017 Oct;131:123-133. doi: 10.1016/j.marenvres.2017.08.001. Epub 2017 Sep 15.
Knowledge and understanding of geographic distributions of species is crucial for many aspects in ecology, conservation, policy making and management. In order to reach such an understanding, it is important to know abiotic variables that impact and drive distributions of native and non-native species. We used an existing long-term macrobenthos database for species presence-absence information and biomass estimates at different environmental gradients in the northern Baltic Sea. Region specific abiotic variables (e.g. salinity, depth) were derived from previously constructed bathymetric and hydrodynamic models. Multidimensional ordination techniques were then applied to investigate potential niche space separation between all native and non-native invertebrates in the northern Baltic Sea. Such an approach allowed to obtain data rich and robust estimates of the current native and non-native species distributions and outline important abiotic parameters influencing the observed pattern. The results showed clear niche space separation between native and non-native species. Non-native species were situated in an environmental space characterized by reduced salinity, high temperatures, high proportion of soft seabed and decreased depth and wave exposure whereas native species displayed an opposite pattern. Different placement of native and non-native species along the studied environmental niche space is likely to be explained by the differences in their evolutionary history, human mediated activities and geological youth of the Baltic Sea. The results of this study can provide early warnings and effectively outline coastal areas in the northern Baltic Sea that are prone to further range expansion of non-native species as climate change is expected to significantly reduce salinity and increase temperature in wide coastal areas, both supporting the disappearance of native and appearance of non-native species.
了解和认识物种的地理分布对于生态学、保护、政策制定和管理的许多方面都至关重要。为了达成这样的认识，了解影响和驱动本地及非本地物种分布的非生物变量很重要。我们利用了一个现有的长期大型底栖动物数据库，获取了波罗的海北部不同环境梯度下物种的有无信息和生物量估计值。特定区域的非生物变量（如盐度、深度）来自先前构建的测深和水动力模型。然后应用多维排序技术来研究波罗的海北部所有本地和非本地无脊椎动物之间潜在的生态位空间分离。这种方法能够获得丰富且可靠的当前本地和非本地物种分布估计数据，并勾勒出影响观测模式的重要非生物参数。结果表明本地和非本地物种之间存在明显的生态位空间分离。非本地物种所处的环境空间特征为盐度降低、温度升高、软质海床比例高、深度减小以及波浪影响减弱，而本地物种则呈现相反的模式。本地和非本地物种在研究的环境生态位空间中的不同分布位置，可能是由它们进化历史、人类介导活动以及波罗的海地质年轻程度的差异所导致的。这项研究的结果可以提供早期预警，并有效地勾勒出波罗的海北部容易出现非本地物种进一步扩散的沿海地区，因为预计气候变化将显著降低广阔沿海地区的盐度并升高温度，这两者都会促使本地物种消失和非本地物种出现。
