Influence of stone bunds on vegetation and soil in an area reforested with Pinus engelmannii Carr. in the forests of Durango, Mexico

The forest ecosystems of Mexico experience soil degradation mainly due to water erosion, which causes low vegetation regeneration. One of the strategies to diminish soil loss is through the construction of stone bunds (SB)-hand-made structures to trap sediment and store water for longer periods. However, little is known about their effects on pine establishment. The objectives of this study were to evaluate the effect of SB on the survival and growth of individual P. engelmannii Carr. specimens with respect to the distance of their planted. The study additionally sought to analyse how SB would affect changes in the production of aerial phytomass, herbaceous vegetation cover and soil characteristics in a reforested area of Durango State in north-central Mexico. Three treatments were evaluated by planting pine trees at three distances with respect to the SB: 80 cm upslope bund (UB), 80 cm downslope bund (DB) and between upper and lower bunds (BB). The variables analysed were the following: The survival and growth of reforestation, aerial coverage and the production of herbaceous plants, and the physicochemical characteristics of the soil. Survival showed significant differences (p < 0.05) among treatments, UB (80%), DB (27%) and BB (30%). The production of aerial phytomass did not show significant differences between treatments UB (1651 kg ha^-1) and DB (1058 kg ha^-1), although these two were different (p < 0.05) to BB (600 kg ha^-1). On the other hand, the vegetation cover and soil characteristics did not show statistical differences. These results highlight the importance of the effect of SB on the survival of P. engelmannii Carr. and the growth of herbaceous vegetation.