Soil properties and their tempo-spatial heterogeneity, affected by visitors’ pressure, season and soil depth, were studied in an urban park in Tel-Aviv. Soil was sampled twice yearly in wet and dry seasons. In each s...Soil properties and their tempo-spatial heterogeneity, affected by visitors’ pressure, season and soil depth, were studied in an urban park in Tel-Aviv. Soil was sampled twice yearly in wet and dry seasons. In each season soil was sampled from areas exposed to differing levels of visitors’ pressure (VP), and designated “no VP (Control)”, “High VP” and “Low VP”. The soil samples were taken from two depths. For each soil sample, moisture, organic matter and soluble-ion contents, pH, and electrical conductivity were determined. It was found that different properties were differently affected by VP, seasonal dynamics and soil depth: organic matter content, penetration depth and sodium concentration were the most sensitive to VP;Soil moisture did not respond to VP, but sharply reflected seasonal changes;Calcium and organic matter contents were significantly affected by the soil depth. The sensitivity of soil properties to VP increased from March to July, and the upper soil layer was more sensitive to seasonal dynamics and VP than the deeper layer. Some soil properties exhibited “spotty” patterns;others a “frontal” one. Organic matter content was completely controlled by VP at both depths and in both seasons, and could be used as an indicator of soil status in recreation areas. Visitors’ activities included trampling and other anthropogenic factors that enhanced the spatial changes and seasonal dynamics of soil properties. Based on these measurements the intensity of soil degradation and dynamics was evaluated and used to describe the soil status in an urban park.展开更多
Various soil surface components, such as trees, shrubs and biological crusts, and human recreational activities, e.g., barbecues and trampling by visitors, may divide the area of the urban park into smaller fragments/...Various soil surface components, such as trees, shrubs and biological crusts, and human recreational activities, e.g., barbecues and trampling by visitors, may divide the area of the urban park into smaller fragments/mieroenvironments, differentiated by their microenvironmental conditions, which may differ in soil and vegetation characteristics. The spatial changes in the soil and vegetation characteristics and their causes were investigated in an urban park located south of Tel Aviv-Jaffa, Israel. The area of the park is 0.5 km^2, including groves, a lake, lawns, and rest areas. Soil was sampled in nine microenvironments, of which seven were within the park： under Ceratonia siliqua trees （CsU）, under Ficus sycomorus trees （FLU）, rest area between tables under F. sycomorus （FIB）, rest area under tables under F. sycomorus （FIT）, open area with bare soil （OaS）, open area with biological crust cover （OaC）, and open area covered by herbaceous vegetation （OaV）. Two more microenvironments, planar and sloping open areas （CoP and CoS, respectively） in the vicinity of the park, were used as the controls. Electrical conductivity, concentrations of soluble ions （Mg^2＋, Ca^2＋, Na^＋, K^＋ and HCO3）, pH, contents of organic carbon, calcium carbonate and moisture, and grain size distribution were determined. In addition, herbaceous vegetation cover, number and diversity of herbaceous vegetation species were measured. It was found that soil properties and herbaceous vegetation characteristics varied within the park. Soil organic carbon, electrical conductivity, soluble salts, penetration depth, and vegetation characteristics were affected by human activities, mainly in the rest area between the tables. In contrast, the above characteristics were affected by natural factors mainly in the rest of the microenvironments, which were subjected to low levels of anthropogenic intervention. The heterogeneous structure of the park, as represented by the various microenvironments, offered new habitats and promoted the preservation of natural vegetation.展开更多
文摘Soil properties and their tempo-spatial heterogeneity, affected by visitors’ pressure, season and soil depth, were studied in an urban park in Tel-Aviv. Soil was sampled twice yearly in wet and dry seasons. In each season soil was sampled from areas exposed to differing levels of visitors’ pressure (VP), and designated “no VP (Control)”, “High VP” and “Low VP”. The soil samples were taken from two depths. For each soil sample, moisture, organic matter and soluble-ion contents, pH, and electrical conductivity were determined. It was found that different properties were differently affected by VP, seasonal dynamics and soil depth: organic matter content, penetration depth and sodium concentration were the most sensitive to VP;Soil moisture did not respond to VP, but sharply reflected seasonal changes;Calcium and organic matter contents were significantly affected by the soil depth. The sensitivity of soil properties to VP increased from March to July, and the upper soil layer was more sensitive to seasonal dynamics and VP than the deeper layer. Some soil properties exhibited “spotty” patterns;others a “frontal” one. Organic matter content was completely controlled by VP at both depths and in both seasons, and could be used as an indicator of soil status in recreation areas. Visitors’ activities included trampling and other anthropogenic factors that enhanced the spatial changes and seasonal dynamics of soil properties. Based on these measurements the intensity of soil degradation and dynamics was evaluated and used to describe the soil status in an urban park.
文摘Various soil surface components, such as trees, shrubs and biological crusts, and human recreational activities, e.g., barbecues and trampling by visitors, may divide the area of the urban park into smaller fragments/mieroenvironments, differentiated by their microenvironmental conditions, which may differ in soil and vegetation characteristics. The spatial changes in the soil and vegetation characteristics and their causes were investigated in an urban park located south of Tel Aviv-Jaffa, Israel. The area of the park is 0.5 km^2, including groves, a lake, lawns, and rest areas. Soil was sampled in nine microenvironments, of which seven were within the park： under Ceratonia siliqua trees （CsU）, under Ficus sycomorus trees （FLU）, rest area between tables under F. sycomorus （FIB）, rest area under tables under F. sycomorus （FIT）, open area with bare soil （OaS）, open area with biological crust cover （OaC）, and open area covered by herbaceous vegetation （OaV）. Two more microenvironments, planar and sloping open areas （CoP and CoS, respectively） in the vicinity of the park, were used as the controls. Electrical conductivity, concentrations of soluble ions （Mg^2＋, Ca^2＋, Na^＋, K^＋ and HCO3）, pH, contents of organic carbon, calcium carbonate and moisture, and grain size distribution were determined. In addition, herbaceous vegetation cover, number and diversity of herbaceous vegetation species were measured. It was found that soil properties and herbaceous vegetation characteristics varied within the park. Soil organic carbon, electrical conductivity, soluble salts, penetration depth, and vegetation characteristics were affected by human activities, mainly in the rest area between the tables. In contrast, the above characteristics were affected by natural factors mainly in the rest of the microenvironments, which were subjected to low levels of anthropogenic intervention. The heterogeneous structure of the park, as represented by the various microenvironments, offered new habitats and promoted the preservation of natural vegetation.
