Gecheva Gana, Pall Karin, Todorov Milcho, Traykov Ivan, Gribacheva Nikolina, Stankova Silviya, Birk Sebastian
Faculty of Biology, Plovdiv University, 4000 Plovdiv, Bulgaria.
Systema GmbH, 8 Bensasteig, 1140 Vienna, Austria.
Plants (Basel). 2021 Dec 9;10(12):2708. doi: 10.3390/plants10122708.
Upland rivers across Europe still exhibit undisturbed conditions and represent a treasure that we cannot afford to lose. We hypothesize that the combination of pristine and modified conditions could demonstrate biological responses along the stressor gradients. Thus, the response of aquatic macrophyte communities to anthropogenic stressors along upland rivers in Bulgaria was studied. Six stressors were selected out of 36 parameters grouped into hydromorphological, chemical variables and combined drivers (catchment land use). The stressors strongly affected species richness on the basis of biological type (bryophytes vs. vascular plants) and ecomorphological type (hydrophytes vs. helophytes). Hydrological alteration expressed by the change of the river's base flow and altered riparian habitats has led to a suppression of bryophytes and a dominance of riverbank plant communities. Seventy-five percent of mountain sites were lacking bryophytes, and the vegetation at semi-mountainous sites was dominated by vascular plants. It can be concluded that hydropeaking, organic and inorganic pollution, and discontinuous urban structures caused important modifications in the aquatic macrophyte assemblages. Macrophyte abundance and the biological and ecomorphological type of aquatic macrophytes reflect multi-stressor effects in upland rivers.
欧洲的高地河流仍然呈现出未受干扰的状态，是我们不能失去的宝贵财富。我们推测，原始状态和受改变状态的组合可能会显示出沿压力梯度的生物响应。因此，研究了保加利亚高地河流中水生大型植物群落对人为压力源的响应。从36个参数中选出6个压力源，这些参数分为水文形态、化学变量和综合驱动因素（集水区土地利用）。这些压力源基于生物类型（苔藓植物与维管植物）和生态形态类型（水生植物与沼生植物）对物种丰富度产生了强烈影响。由河流基流变化和河岸栖息地改变所表现出的水文变化导致了苔藓植物受到抑制，河岸植物群落占主导地位。75%的山区没有苔藓植物，半山区的植被以维管植物为主。可以得出结论，水位急剧变化、有机和无机污染以及不连续的城市结构对水生大型植物组合造成了重要改变。大型植物的丰度以及水生大型植物的生物和生态形态类型反映了高地河流中的多重压力效应。
