Factors of Natural Regeneration of Platycladus orientalis (L.) Franco in Guilin, China

Abstract

Cypress (Platycladus orientalis (L.) Franco) is one of the important evergreen trees for afforestation in barren mountains, soil consolidation, and water conservation, but natural regeneration of cypress is complex and slow. An understanding of the influence mechanism of the natural regeneration of cypresses is essential for elevating survival and regeneration. This study aimed to clarify the relationship between stand factors, environmental factors, and regeneration of cypress plantations. A total of 42 cypress sample plots in Guilin, China, were selected to evaluate the impact of various stand factors and environmental factors on the regeneration of cypresses using survey statistics and Pearson and Spearmanrank correlation analysis. In this study, cypress has the highest frequency and density of regeneration among all the seedlings in the 18 surveyed forests, but the height structure of cypress seedlings distributes in uneven mode and mainly Grade I (height < 30 cm) seedlings. Low-density herbs and high-density moss mulching had a directly positive effect on the number of cypress regeneration seedlings. Larger soil stone content and gap area can promote cypress regeneration, which is appropriate for cypresses in the seedling stage. In conclusion, timely weeding, proper soil loosening, and improving light transmittance contribute to promoting the regeneration of cypresses.