scholarly journals Variability response of aquatic macrophytes in inland lakes: A case study of Lake Nasser

2021 ◽  
Vol 47 (3) ◽  
pp. 245-252
Author(s):  
Amany M. Haroon ◽  
Radwan G. Abd Ellah
2020 ◽  
Vol 20 (1) ◽  
Author(s):  
Hailong Yu ◽  
Zhenfa Tu ◽  
Guangming Yu ◽  
Lili Xu ◽  
Hongzhi Wang ◽  
...  

Plants ◽  
2021 ◽  
Vol 10 (12) ◽  
pp. 2708
Author(s):  
Gana Gecheva ◽  
Karin Pall ◽  
Milcho Todorov ◽  
Ivan Traykov ◽  
Nikolina Gribacheva ◽  
...  

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.


2018 ◽  
Vol 37 (2) ◽  
pp. 665-674
Author(s):  
Changbo Yuan ◽  
Tianshun Zhu ◽  
Te Cao ◽  
Yilong Xi ◽  
Xiaolin Zhang ◽  
...  

2016 ◽  
Vol 113 (27) ◽  
pp. 7443-7448 ◽  
Author(s):  
Meghan C. L. Howey ◽  
Michael W. Palace ◽  
Crystal H. McMichael

Building monuments was one way that past societies reconfigured their landscapes in response to shifting social and ecological factors. Understanding the connections between those factors and monument construction is critical, especially when multiple types of monuments were constructed across the same landscape. Geospatial technologies enable past cultural activities and environmental variables to be examined together at large scales. Many geospatial modeling approaches, however, are not designed for presence-only (occurrence) data, which can be limiting given that many archaeological site records are presence only. We use maximum entropy modeling (MaxEnt), which works with presence-only data, to predict the distribution of monuments across large landscapes, and we analyze MaxEnt output to quantify the contributions of spatioenvironmental variables to predicted distributions. We apply our approach to co-occurring Late Precontact (ca. A.D. 1000–1600) monuments in Michigan: (i) mounds and (ii) earthwork enclosures. Many of these features have been destroyed by modern development, and therefore, we conducted archival research to develop our monument occurrence database. We modeled each monument type separately using the same input variables. Analyzing variable contribution to MaxEnt output, we show that mound and enclosure landscape suitability was driven by contrasting variables. Proximity to inland lakes was key to mound placement, and proximity to rivers was key to sacred enclosures. This juxtaposition suggests that mounds met local needs for resource procurement success, whereas enclosures filled broader regional needs for intergroup exchange and shared ritual. Our study shows how MaxEnt can be used to develop sophisticated models of past cultural processes, including monument building, with imperfect, limited, presence-only data.


2018 ◽  
Vol 6 (1) ◽  
pp. 8
Author(s):  
T.D. Samudrika Sandaruwani ◽  
K. S. S. Atapaththu ◽  
H. B. Asanthi

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