Method for Classifying Behavior of Livestock on Fenced Temperate Rangeland in Northern China

Different livestock behaviors have distinct effects on grassland degradation. However, because direct observation of livestock behavior is time- and labor-intensive, an automated methodology to classify livestock behavior according to animal position and posture is necessary. We applied the Random Forest algorithm to predict livestock behaviors in the Horqin Sand Land by using Global Positioning System (GPS) and tri-axis accelerometer data and then confirmed the results through field observations. The overall accuracy of GPS models was 85% to 90% when the time interval was greater than 300–800 s, which was approximated to the tri-axis model (96%) and GPS-tri models (96%). In the GPS model, the linear backward or forward distance were the most important determinants of behavior classification, and nongrazing was less than 30% when livestock travelled more than 30–50 m over a 5-min interval. For the tri-axis accelerometer model, the anteroposterior acceleration (–3 m/s2) of neck movement was the most accurate determinant of livestock behavior classification. Using instantaneous acceleration of livestock body movement more precisely classified livestock behaviors than did GPS location-based distance metrics. When a tri-axis model is unavailable, GPS models will yield sufficiently reliable classification accuracy when an appropriate time interval is defined.

Soil water response to rainfall in a dune-interdune landscape in Horqin Sand Land, northern China

Soil water dynamic is considered an important process for water resource and plantation management in Horqin Sand Land, northern China. In this study, soil water content simulated by the SWMS-2D model was used to systematically analyse soil water dynamics and explore the relationship between soil water and rainfall among micro-landforms (i.e., top, upslope, midslope, toeslope, and bottomland) and 0–200 cm soil depths during the growing season of 2013 and 2015. The results showed that soil water dynamics in 0–20 cm depths were closely linked to rainfall patterns, whereas soil water content in 20–80 cm depths illustrated a slight decline in addition to fluctuations caused by rainfall. At the top position, the soil water content in different ranges of depths (20–40 and 80–200 cm) was near the wilting point, and hence some branches, and even entire plants exhibited diebacks. At the upslope or midslope positions, the soil water content in 20–80 or 80–200 cm depths was higher than at the top position. Soil water content was higher at the toeslope and bottomland positions than at other micro-landforms, and deep caliche layers had a positive feedback effect on shrub establishment. Soil water recharge by rainfall was closely related to rainfall intensity and micro-landforms. Only rainfalls > 20 mm significantly increased water content in > 40 cm soil depths, but deeper water recharge occurred at the toeslope position. A linear equation was fitted to the relationship between soil water and antecedent rainfall, and the slopes and R² of the equations were different among micro-landforms and soil depths. The linear equations generally fitted well in 0–20 and 20–40 cm depths at the top, upslope, midslope, and toeslope positions (R² value of about 0.60), with soil water in 0–20 cm depths showing greater responses to rainfall (average slope of 0.189). In 20–40 cm depths, the response was larger at the toeslope position, with a slope of 0.137. In 40–80 cm depths, a good linear fit with a slope of 0.041 was only recorded at the toeslope position. This study provides a soil water basis for ecological restoration in similar regions.

Rainfall partitioning characteristics of three typical sand-fixing shrubs in Horqin Sand Land, north-eastern China

Rainfall partitioning by vegetation affects water balance and utilization by plants. Caragana microphylla, Hedysarum fruticosum, and Salix gordejevii are three typical, morphologically different sand-fixing shrubs in Horqin Sand Land. However, few studies have compared rainfall partitioning by these shrubs. We examined rainfall partitioning differences among these shrubs in Horqin Sand Land, north-eastern China. On average, throughfall, stemflow (SF), and interception for C. microphylla accounted for 64.2, 11.0, and 24.8% of the individual incident rainfall, respectively; for H. fruticosum, they accounted for 71.2, 6.3, and 22.5%; and for S. gordejevii, they accounted for 75.3, 5.3, and 19.4%. The average funneling ratio for H. fruticosum (162.7 ± 33.2) was larger than that for C. microphylla (100.1 ± 16.9) and S. gordejevii (106.2 ± 23.1). Rainfall partitioning was significantly correlated with canopy area, branch number, and stem basal area for C. microphylla and S. gordejevii. SF volumes of 3,167, 676, and 2,210 L were estimated to have channeled into the plots for C. microphylla, H. fruticosum and S. gordejevii, respectively, indicating that C. microphylla is more effective in channeling SF to the root zone. These results suggest that C. microphylla may be more advantageous for sand-fixing and vegetation restoration in sand lands.