人为干扰栖息地退化对潮间带中华鲎幼鲎种群数量的影响

栖息地退化是中华鲎（Tachypleus tridentatus）面临的主要威胁因素。然而，人类活动和中华鲎栖息地退化之间的关系研究尚且不足。为了厘清人类活动对中华鲎幼鲎栖息地退化的影响，以北部湾潮间带为研究范围，于2014、2017和2020年对潮间带中华鲎幼鲎丰度进行随机样方法调查，并获取对应年份遥感影像（分辨率30m）作为数据源，借助GIS空间分析、景观格局分析和人为干扰度指数（human disturbance index，HDI）模型，量化评估人为干扰对北部湾潮间带中华鲎幼鲎栖息地景观格局及种群丰度的影响。结果表明：（1）2014-2020年，北部湾潮间带幼鲎栖息地退化严重，无干扰类型景观面积逐渐减少，大部分转化为养殖；（2）北部湾潮间带人为干扰逐渐加强，无干扰等级HDI指数面积不断减少，潮间带大部分面积HDI指数呈增强趋势；（3） HDI指数与幼鲎种群丰度呈显著负相关性，HDI指数高值斑块不适合幼鲎生存。依据HDI指数动态变化及空间分布，可为潮间带中华鲎幼鲎种群栖息地景观格局优化及鲎人工放流增殖选址等保护行动提供理论依据。

Effects of habitat degradation due to human activities on abundance of juvenile Tachypleus tridentatus in the intertidal zone

Habitat degradation is a major threat to Tachypleus tridentatus (T. tridentatus). In order to distinguish the effects of human activities on habitat degradation of juvenile T. tridentatus, the abundance of juvenile T. tridentatus in the intertidal zone was investigated by random sampling method at 2014, 2017 and 2020, and the remote sensing images with resolution of 30 m were obtained in corresponding years. With the help of GIS spatial analysis and landscape pattern analysis and the human disturbance index (HDI) model, the effects of human disturbance on the landscape pattern and population abundance of juvenile T. tridentatus in the intertidal zone of Beibu Gulf were quantitatively evaluated. The results show that:(1) The suitable habitat of juvenile limulus in the intertidal zone of the Beibu Gulf deteriorated seriously. The area of undisturbed landscape as almost undisturbed by human decreased gradually, most of which were transformed into aquaculture. Adversely, the landscapes that might pose the greatest threat to the survival of horseshoe crabs are residential areas and port terminals. The increasing area of these unsuitable landscapes would cause the fragmentation of suitable habitats and reduce the quality of ecological environment, which is not conducive to the survival of juvenile horseshoe crabs. (2) The anthropogenic interference in the intertidal zone of Beibu Gulf was gradually strengthened. The area of HDI with undisturbed level was reduced, and the HDI of most areas in the intertidal zone showed an increasing trend. (3) The HDI was significantly negatively correlated with the population abundance of juvenile T. tridentatus. The abundance of juvenile T. tridentatus decreased with the increase of HDI. This result suggests that the high-value patches of HDI were not suitable for the survival of juvenile T. tridentatus. Based on the dynamic change and spatial distribution of HDI index, the optimization of habitat landscape pattern, the construction of protected areas and the site selection of artificial discharge and proliferation will be scientifically and effectively guided.