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ŠUMARSKI LIST 9-10/2018 str. 80     <-- 80 -->        PDF

of different tourism disturbance intensities on carbon, nitrogen, and enzyme activities of the soil in a subtropical urban park. It is anticipated this work will provide a scientific basis that can be used to protect and rationally utilize subtropical urban parks better.
Study site – Područje istraživanja
The research area is Chengdu, China, located at 30o05’~31o26’ N, 102o54’~104o53’ E. The altitude is approximately 500 m. Chengdu’s mean annual temperature as calculated from multiple years’ records is 16.2 oC. The annual maximum and minimum temperatures are 37.3 oC and - 5.9 oC, respectively. The mean annual number of sunshine hours is 1071 hous. The mean annual precipitation is 945.6 mm, and the annual frost-free period is above 337 days. It is warm year-round, and the four seasons are distinct. The soil in the study area is referred to as purple soil and classified as Pup-Orthic Entisols in the Chinese soil taxonomy and Eutric Regosol in the Food and Agriculture Organization’s Soil Classification. Chengdu is a mid-subtropical region, and the main type of vegetation is that of the subtropical evergreen broad-leaved forest.
Experimental setup – Plan pokusa
The experiment was conducted in September 2016 in Huanhuaxi Park in Chengdu. The location of this park is shown in Figure 1. Three common types of plant communities were chosen, whose dominant species are Ulmus pumila L., Ligustrum lucidum, and Ficus virens, respectively. For each sample plot of the plant communities, the sightseeing road of the scenic area was taken as the center, and three parallel belt transects were set along the vertical direction to one side of the sightseeing road (close to the side with more plant trampling), and the spacing between each transect was more than 5 meters (Figure 2). The starting point of the belt transect was located at the edge of the sightseeing road, and quadrates of 1 m×1 m were set at 1 m, 5 m, and 10 m away from the sightseeing road, representing heavy, moderate, and light tourism disturbances, respectively (Figure 2). Three quadrates with the same distance from the starting point distributed on three parallel belt transects were considered as three sampling replicates. In each quadrate, a 5 cm-diameter soil borer was used, and five random drills of soil within the range of 0 - 15 cm were collected. The five samples were then mixed to form one composite sample of about 1 kg. The soil was passed through a 2 mm sieve and then divided into two parts (Tian et al., 2017). One part of the soil was air-dried and ground to pass through a 0.2 mm sieve to test the soil