Factors of the Ecosystem Service Value in Water Conservation Areas Considering the Natural Environment and Human Activities: A Case Study of Funiu Mountain, China

Water conservation areas play an important role in regional ecological security patterns. The Funiu Mountain water conservation area is located in the densely populated central region of China, where human disturbance to the ecosystem is strong and ecosystem services are facing a very serious situation. Identifying and evaluating the factors leading to changes in the ecosystem service value (ESV) of the Funiu Mountain water conservation area can provide scientific guidance for ecological management and sustainable development. Using multi-source data and machine learning methods, our research reveals the characteristics of the spatio-temporal variation in the ESV, constructs a system of ESV influencing factors from the comprehensive perspectives of the natural environment and human activities, and discusses the comprehensive effects of the influencing factors on the Funiu Mountain area from 2000 to 2015. The results are as follows. (1) From 2000 to 2005, the ESV increased 375 million yuan, and from 2005 to 2015, it decreased 154 million yuan. (2) Hydrological regulation, biodiversity maintenance, soil conservation, gas regulation, and climate regulation were the main types of ecosystem services in the Funiu Mountain area. (3) The ESV was influenced by the comprehensive effects of the natural environment and human activities. Population was the most important influencing factor of the ESV; in addition, the normalized difference vegetation index (NDVI), precipitation, and economic factors had important influences on the ESV. (4) With the intensification of human activities, humanistic factors have surpassed the relatively stable natural factors, becoming the main factors of the ESV. With economic development, the effect of human activities on the ESV may be further intensified in the future.

The impacts of piers on oil spill transport in a typical reach of the Middle Yangtze River

Oil spill, a frequent pollution in the utilization of rivers, is receiving increasing attention in the study of river ecosystem. Taking the Zhuankou–Yangluo Reach (ZYR) of the Middle Yangtze River as an example, the spatial and temporal behaviors of leaked oil in the river under uniformly arranged piers with varying densities were studied based on a MIKE21 hydrodynamic and oil drift model. The results show that the oil spill spread is less affected by the piers when the upstream oil spill point locates on the different side of the shoreline with piers. However, the influences of the piers at the same shoreline of the oil spill point on oil spill transportation cannot be ignored. The piers significantly reduce the oil spill drift speed in the engineering area, resulting in a significant increase in slick retention time and slick area, especially when the density of piers is greater than 1.25 units/km. These results will provide useful reference for river management, for example, in the upstream river of the water conservation area, especially in the same bank of the water intake, where a large number of piers should not be built.

Linking soil water and solutes fluxes to soil properties and vegetation types: insights from a case-study in the high tropical Andes of Ecuador

<p>The high tropical Andes ecosystem, known as páramo, provides important hydrological services to densely populated areas in the Andean region. In order to manage these services sustainably, it is crucial to understand the biotic and abiotic processes that control both water quality and fluxes. Recent research in the páramo highlights a knowledge gap regarding the role played by soil-vegetation interactions in controlling soil-water processes and resulting water and solute fluxes.</p><p>Here, we determine the hydrological and geochemical fluxes in four soil profiles in the páramo of the Antisana´s water conservation area in northern Ecuador. Water fluxes were measured biweekly with field fluxmeters in the hydrological year Apr/2019- Mar/2020 under two contrasting vegetation types: tussock-like grass (TU) and cushion-forming plants (CU). Soil solution was collected in parallel with wick samplers and suction caps for assessing the concentrations of dissolved cations, anions and organic carbon (DOC). In addition, soil moisture was measured continuously in the upper meter of the soil profile, i.e. first three horizons (A, 2A and 2BC), using water content reflectometers. The vertical water flux in the upper meter of each soil profile was simulated using the 1D HYDRUS model. We carried out a Sobol analysis to identify sensitive soil hydraulic parameters. We then derived water fluxes by inverse modeling, based on the measured soil moisture. We validated the calculated water fluxes using the fluxmeter data. Solute fluxes were estimated by combining the water fluxes and the soil solution compositions.</p><p>Our preliminary results suggest that water fluxes and DOC concentration vary under different vegetation types. The fluxmeter data from the 2A horizon indicates that the cumulative water flux under TU (2.8 - 5.7 l) was larger than under CU (0.8 – 1.1 l) during the dry season (Aug-Sep and Dec-Jan). However, the opposite trend was observed in the wet season for maximum water fluxes. Moreover, the DOC concentration in the uppermost horizon was higher under CU (47.3 ±2.2 mg l<sup>-1</sup>) than under TU (3.1 ±0.2 mg l<sup>-1</sup>) vegetation during the monitoring period. We associate the water and solute responses under different vegetation types to the contrasting soil hydro-physical and chemical properties (e.g., saturated hydraulic conductivity and organic carbon content) in the uppermost soil horizon. Our study illustrates the existence of a spatial association between vegetation types, water fluxes and solute concentrations in Antisana´s water conservation area. By modelling the hydrological balance of the upper meter of the soil mantle, the water and solute fluxes will be estimated for soils with different vegetation cover.</p><p> </p>

Population Estimates and Habitat Selection of White-tailed Deer (Odocoileus virginianus ustus) in the Antisana Water Conservation Area, Ecuador

The Antisana Water Conservation Area (ACHA) greatly contributes to the water supply of the Metropolitan District of Quito (DMQ). Therefore, integrated management of the area needs to take into account the ecological interactions that sustain the interception and slow release of water by the vegetation and soil. An apparent increase in the population of white-tailed deer has led to the concern that this herbivore may alter the vegetation and thus the water cycle. In this study, we obtain the first population estimates for white-tailed deer in ACHA and the second estimate for the Ecuadorean Andes. Vantage point counts (VPC) set the minimum population for the reserve at 760 individuals, whereas the fecal standing crop (FSC) indirect method determined an estimate of 953 ± 368 (90% confidence interval) for a density of 11.27 individuals/km2. The density of deer is low compared to other sites in the Colombian and Venezuelan Andes. From a management perspective, the optimal number of deer for the reserve will depend on the impact the deer have on the ideal composition of plants for the long-term production of water.