Spatial distribution characteristics of a Pinus tabuliformis forest in the central dry zone of Ningxia, China

ABSTRACTPinus tabuliformis is a forest-building species in the Luoshan National Nature Reserve, Ningxia, China, and has crucial ecological value. Understanding its spatial distribution can play an important role in ecosystem management and conservation. Here, the spatial point pattern method was used to analyse the spatial renewal pattern of 2037 living and dead pine seedlings, young trees and large trees and to study the correlation between the distribution of seedlings/young trees and large trees. The results showed that: the P. tabuliformis trees varied moderately in size; the proportion of live plants was 82% in the youngest age class, 97% in the middle age class and 100% in the oldest age class, indicated a growing adaptation to environment; the point pattern of the P. tabuliformis population was generally randomly distributed but showed aggregation at smaller spatial scales for seedlings and young trees; there was no spatial correlation between surviving and dead plants and a weak positive correlation to no correlation among surviving plants of the three age classes (I, seedlings; II, young trees; III, dead trees); and, in general, there was no spatial correlation between dead and live plants. The spatial correlation between dead age-class I plants and living age-class II plants was positive at the spatial scales of 0–1.9 m. The P. tabuliformis population was affected by intraspecies competition and limited resources and space in the central dry zone of Ningxia. The number of seedlings growing into large trees is very small, and the competition for space in the upper canopy of the forest affects the renewal of seedlings and young trees. These findings are used to propose two management interventions for P. tabuliformis forests.KEYWORDS: Luoshan National Nature ReservePinus tabuliformisspatial point pattern analysisspatial correlation Disclosure statementNo potential conflict of interest was reported by the author(s).Additional informationFundingFunded by the Ningxia Key R&D Project: Key Technology Research and Demonstration of Ecological Restoration and Function Enhancement in Luoshan National Nature Reserve [2021BEG02009].