RESUMEN
Accurate assessment of material and energy exchange between land and atmosphere is essential for water resources management and sustainable development of agriculture. To understand the characteristics of energy distribution and the dynamic change process of water and heat fluxes within the maize farmland ecosystem in the old course of Yellow River and their response to meteorological factors, we utilized the eddy covariance measurements and the full-element automatic weather station to continuously observe energy fluxes and conventional meteorological elements of summer maize farmland in the old course of Yellow River during 2019-2020. We analyzed the variation of energy fluxes and the effects of environmental factors, such as temperature, precipitation, and wind speed. Additionally, we calculated the energy closure rate and the proportion of energy distribution during the growth stage. The results showed that the peaks of net radiation, sensible heat flux, and latent heat flux occurred between 11:00 and 14:00, and the peak of soil heat flux occurred between 14:00 and 15:00. In terms of energy distribution, energy consumption of summer maize farmland during the whole growth period was dominated by latent heat flux and sensible heat flux. Energy was mainly consumed by sensible heat flux at sowing-emergence stage, accounting for 37.1% of net radiation, respectively. Energy in the rest of growth stages was dominated by latent heat flux. The energy closure rate during the whole growth period was better, with a coefficient of determination of 0.83, and the closure rate was higher in day and lower at night. Precipitation affected latent heat flux and sensible heat flux, and latent heat flux was more sensitive to precipitation. The increase of latent heat flux after rainfall was lower in late growth stage than in early growth stage. During the whole growth period of summer maize, solar radiation was the most significant meteorological factor affecting both sensible heat flux and latent heat flux, followed by vapor pressure deficit. The contribution of temperature and vapor pressure deficit to latent heat flux was significantly higher than sensible heat flux, while the relative contribution of wind speed, relative humidity, and solar radiation to latent heat flux was lower than sensible heat flux. Leaf area index and fractional vegetation cover had a significant positive correlation with latent heat flux and a significant negative correlation with sensible heat flux. Our results could deepen the understanding of water and heat transfer law of summer maize farmland in the old course of Yellow River, providing a theoretical basis for efficient water use of crops.
Asunto(s)
Ecosistema , Calor , Ríos , Estaciones del Año , Zea mays , Zea mays/crecimiento & desarrollo , China , Agua/análisisRESUMEN
We analyzed the relationship between the distribution of amphibians and the environmental variables at the habitat level and landscape level in Fengqiu County of Henan Province, a typical region of the lower reaches of the Yellow River, with the support of geographic information system (GIS) and R software. At the habitat level, dissolved oxygen (DO), conductivity (COND), turbidity (TURB), NH3-N, pond-interior vegetation cover (VEGinterior), emergent vegetation cover (EMER), pond-edge vegetation cover (VEGedge), benthic fauna predators (PRE), and pond area (AREA) were selected as habitat variables. At the landscape level, total area of ponds (AP), distance to the nearest road (DR), total area of farmlands (AF), total area of woodlands (AW), Shannon’s diversity index (SHDI), and contagion index (CONTAG) were selected as explanatory variables, calculated within a buffer of 250, 500, 1000 and 2000 m around the centroid of each pond. The results showed that the distribution of Bufo gargarizans was mainly related to the PRE and landscape variables within the larger radius buffer zone (AW2000, DR2000, SHDI1000, CONTAG1000). The distribution of Pelophylax nigromaculata was closely related to the EMER and landscape variables within the smaller radius buffer zone (SHDI500). VEGinterior and PRE were the key factors determining the distribution of Pelophylax plancyi. Landscape variables (AF2000, SHDI2000) within the larger buffer radius were the most significant influencing factors on Fejervarya multistriata. For all amphibian species, the EMER and SHDI500 were variables that should be considered. For the protection of amphibian species in plain agricultural landscape, we suggested that conservation efforts should focus on improving the pond-interior vegetation cover, protecting the semi-permanent ponds, and enhancing the functional connectivity among ponds.
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Agricultura , Anfibios , Monitoreo del Ambiente , Animales , Ecosistema , Estanques , RíosRESUMEN
Intensive agriculture is the way for production and management in modern agriculture, which increases the yield per unit area of farmland, brings a series of environmental and ecological problems, and limits the sustainability of agriculture. Landscape preference focuses on different stakeholders' preferences for landscape, reflects the influences of human's subjective feelings and behaviors on landscape. Based on the agricultural landscape of Fengqiu County in Henan Province, we investigated the characteristics of the landscape elements which stakeholders preferred and analyzed the reasons using the questionnaire survey and other related methods. We proposed several suggestions for future development of the agricultural landscape in study area. The results showed that stakeholders preferred the landscape element which is simple and easy to manage, and emphasized the production and economic functions of agricultural landscape. Experts and local environmentalists preferred the landscape elements with multiple functions and benefits, as well as complex landscape configurations with high heterogeneity, with the aim to develop the multifunctional agricultural landscape. Factors such as education level, professional background and types of intervie-wees had obvious influences on the landscape preference of stakeholders. The decision-making beha-vior of government, the degree of economic compensation, and the technological support of eco-agriculture would be the important factors determining the possible development of landscape structure and function in the future.
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Agricultura , Conservación de los Recursos Naturales , Ecología , HumanosRESUMEN
Riparian buffer zone is important ecological transitional region between river and upland. Restoring the degraded vegetation system is important for preventing soil erosion, improving ecological environment and helping to achieve the sustainable development of ecosystems. Based on the scenario simulation of vegetation pattern and flow length index, we analyzed the responses of hydrological connectivity to vegetation pattern under different vegetation coverages and slope gradients, and explored the optimal vegetation pattern of soil and water conservation in riparian buffer zone in the lower reaches of the Yellow River. The results showed that the midslope-coarsness-clustered distribution of vegetation configuration, which exhibited the shortest flow length and the weakest hydrological connectivity, being the optimal vegetation pattern for controlling slope runoff generation and flow concentration. For the optimal vegetation pattern, its flow length increased with increasing slope length, namely, the longer slope length the more significant difference of hydrological connectivity between different slope gradients. Meanwhile, flow length of the optimal vegetation pattern decreased with increasing vegetation coverage. The differences between different slope gradients were obvious under low vegetation coverage, while it was unobvious on slope with vegetation coverage of 45%. Compared with the irregular variation trend of flow length on the actual vegetation slope, there was a consistent trend of first increase and then decrease on the simulated slope with the optimal vegetation pattern. Within the pre-set slope gradient range (5°-20°), the optimal vegetation pattern changed the variation of flow length between different slope gradients in the process of coverage change, which highlighted the influence of riparian buffer zone vegetation pattern on hydrological connectivity.
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Conservación de los Recursos Naturales , Ríos , Ecosistema , Hidrología , SueloRESUMEN
Soil phosphorus is an important indicator to measure the soil fertility, because the content of soil phosphorus has an important effect on physical and chemical properties of soil, plant growth, and microbial activity in soil. In this study, the soil samples collecting and indoor analysis were conducted in Zhoukou City located in the flooded area of the Yellow River. By using GIS combined with geo-statistics, we tried to analyze the spatial variability and content distribution of soil total phosphorus (TP) and soil available phosphorus (AP) in the study area. Results showed that TP and AP of both soil layers (0-20 cm and 20-40 cm) were rich, and the contents of TP and AP in surface layer (0-20 cm) were higher than in the second layer (20-40 cm). TP and AP of both soil layers exhibited variation at medium level, and AP had varied much higher than TP. TP of both layers showed medium degree of anisotropy which could be well modeled by the Gaussian model. TP in the surface layer showed strong spatial correlation, but that of the second layer had medium spatial correlation. AP of both layers had a weaker scope in anisotropy which could be simulated by linear model, and both soil layers showed weaker spatial correlations. TP of both soil layers showed a slowly rising change from southwest to northeast of the study area, while it gradually declined from northwest to southeast. AP in soil surface layer exhibited an increase tendency firstly and then decrease from southwest to the northeast, while it decreased firstly and then increased from southeast to the northwest. AP in the second soil layer had an opposite change in the southwest to the northeast, while it showed continuously increasing tendency from northwest to the southeast. The contents of TP and AP in the surface layer presented high grades and the second layer of TP belonged to medium grade, but the second layer of AP was in a lower grade. The artificial factors such as land use type, cropping system, irrigation and fertilization were the main factors influencing the distribution and spatial variation of soil phosphorus in this area.
Asunto(s)
Fósforo/análisis , Suelo/química , China , Inundaciones , Sistemas de Información Geográfica , Ríos , Análisis EspacialRESUMEN
SelectingFengqiu County in Henan Province, a typical region of the lower Yellow River, as the study area, adopting the analysis method of graph theory, with the support of geographic information systems (GIS) and R software, we analyzed the effects of landscape composition and landscape configuration, the mean pond size (MS), the number of ponds (NP), and distance to the nearest roads (DR), on habitat availability of amphibian species under different levels of dispersal ability (250, 500, 1000 and 2000 m), by referring the probability index of connectivity (PC) and the important value of patches (percentage of the variation in PC, dPCk) to the degree of availability of ponds for amphibians' breeding. The results indicated that the ponds availability for amphibians' breeding was closely related to MS, NP, and DR. Therein, MS and NP were the key factors determining the availability of ponds under the dispersal ability of 250 m, and then MS and DR were the most significant influencing factors on pond availability under the dispersal ability of 500 m. However, under the high dispersal ability (1000 and 2000 m), MS and NP were the most important factors determining the availability of ponds. Therefore, with regard to the protection of amphibian species and their habitats in plain agricultural landscape, the number, mean size, and distances to the nearest roads of ponds should be taken into full consideration.
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Anfibios , Ecosistema , Estanques , Agricultura , Animales , China , Conservación de los Recursos Naturales , Monitoreo del Ambiente , RíosRESUMEN
With the development of social economy, human disturbance has resulted in a variety of ecosystem service degradation or disappearance. Ecosystem services flow plays an important role in delivery, transformation and maintenance of ecosystem services, and becomes one of the new research directions. In this paper, based on the classification of ecosystem services flow, we analyzed ecosystem service delivery carrier, and investigated the mechanism of ecosystem service flow, including the information, property, scale features, quantification and cartography. Moreover, a tentative analysis on cost-effective of ecosystem services flow (such as transportation costs, conversion costs, usage costs and cost of relativity) was made to analyze the consumption cost in ecosystem services flow process. It aimed to analyze dissipation cost in ecosystem services flow process. To a certain extent, the study of ecosystem service flow solved the problem of "double counting" in ecosystem services valuation, which could make a contribution for the sake of recognizing hot supply and consumption spots of ecosystem services. In addition, it would be conducive to maximizing the ecosystem service benefits in the transmission process and putting forward scientific and reasonable ecological compensation.
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Conservación de los Recursos Naturales/economía , Análisis Costo-Beneficio , Ecosistema , Ecología , HumanosRESUMEN
Eco-services provided by non-agricultural organisms are the basis of ecosystem to keep its stability in agricultural landscapes. With the strengthening of agricultural intensification, the ongoing loss of biodiversity is one of the most extrusive issues in the development of modern agriculture. In this paper, the study area was set up in Gongyi County, a typical agricultural region in the middle and lower reaches of the Yellow River. According to its typical topography (mountain-hilly-plain) type, we explored the effects of landscape heterogeneity on the diversity of pollinators at three different scales, which were geomorphic categories, landscape and habitat. Pan traps were used to obtain pollinators in this study. The effects of agricultural landscape heterogeneity at multi-scales on the diversity of pollinators were analyzed by using multivariable ANOVA. The results showed that a total of 67012 pollinator individuals that belonged to 86 classes and 7 subjects were classified. The dominant groups inclu-ded Syrphidae and Anthomyiidae. The common groups included Drosophilidae, Calliphoridae, Bombyliidae, Pipunculidae, Cantharidae, Cynipidae, Vespidae, Chalalcididae, Megachilidae and Apidae. Geomorphic categories showed the most significant impact on pollinators (P<0.001), suggesting that hilly and mountainous areas were the pollinators' ground of nectar. It was followed by habitat scale (P<0.05), with non-significant effect on the scales of landscape and the interaction between scales. The effect of landscape heterogeneity on the diversity of pollinators in hilly and mountainous areas provided a theoretical support for landscape planning and biodiversity conservation on the local area with different geomorphic categories.
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Agricultura , Biodiversidad , Ecosistema , Insectos/clasificación , Polinización , Animales , Abejas , China , Escarabajos , RíosRESUMEN
Soil and vegetation are the foundation of maintaining riparian ecosystem services, and their spatial distribution and variations can determine the effects of ecological functions. In the present study, selecting the typical reach of the middle and lower reaches of the Yellow River as the study area, the spatial distributions of riparian soil physicochemical properties and their response to environmental factors were analyzed by employing methods of field investigation, experimental analysis, and redundancy analysis (RDA). The results showed that soil particle was composed significantly of silt in the study area, with the increase of riparian buffer distance, soil bulk density increased initially and then decreased, whereas soil moisture showed the opposite pattern. Changes in total soil phosphorus (TP), available phosphorus (AP), total carbon (TC), total organic carbon (TOC), total nitrogen (TN); ammonium nitrogen (NH4âº-N) and nitrate nitrogen (NO3â»-N) contents under different riparian buffer distance showed no statistically significant differences. The spatial distribution of soil chemical properties was generally insignificantly different through changes between two vegetation types. Pearson correlation analysis showed that there was close relationship between soil physical and chemical properties, therein, TOC content in the study area was positively and significantly related to TN (P < 0.01), NO3â»-N (P < 0.01, and NH4âº-N (P < 0.05) contents, respectively. Both the TN and TOC contents were significantly negatively related to sand content (P < 0.01), while was significantly positively related to clay content (P < 0.01), indicating that high sand content cou ld pormote poro9sity and permeability of soil and then accelerate the degradation rate of organic matters in soils. In addition, the results of RDA indicated that TOC and NH4âº-N contents increased with increasing the height and coverage of the tree layer. Soil TP and NO3â»-N contents increased with increasing the plant diameter at breast height (DBH) of the tree layer and coverage of the herb layer. Meanwhile, with the increase of elevation gradient, the content of soil NH4âº-N presented an increasing trend, indicating that soil properties were significantly influenced by the effects of community structure and elevation gradient in the study area.