Spatial patterns and interspecific associations among trees at different stand development stages in the natural secondary forests on the Loess Plateau, China

Abstract

Quercus wutaishansea populations on the Loess Plateau are currently becoming more dominant in natural secondary forests, whereas Pinus tabulaeformis is declining. In the present paper, the diameter class (instead of age) was used to classify the different growth stages as juvenile, subadult, or adult, and the univariate function g(r) was used to analyze the dynamic changes in spatial patterns and interspecific associations in three 1‐ha tree permanent plots on the Loess Plateau, NW China. Our results suggested that the niche breadth changed with the development stage. The diameter distribution curve was consistent with the inverted “J” type, indicating that natural regeneration was common in all three plots. There was a close relationship between the spatial pattern and scale, which showed significant aggregation at small distances, and became more random as distance increased, but in the Pinus + Quercus mixed forests, the whole species were aggregated at distances up to 50 m. The degree of spatial clumping decreased from juvenile to subadult and from subadult to adult. The spatial pattern also differed at different growth stages, likely due to strong intraspecific competition. Associations among different growth stages were positively correlated at small scales. Our study is important to the understanding of the development of the Q. wutaishansea forests; thus, the spatial dynamic change features should be received greater attention when planning forest management and developing restoration strategies on the Loess Plateau.

Spatial pattern analysis of forest trees based on the vectorial mark

“…Previous spatial analytical methods have described the scattering of individual trees and the spatial distribution of tree size, whereas our newly proposed spatial analysis methods use new quantitative and vectorial marks to determine the driving factors that led to the spatial patterns. That is, traditional methods only analyze unmarked and quantitatively marked patterns such as a significant segregated distribution of certain species adults and a significant clustered distribution of subadults and juveniles at extreme small scales (Nguyen et al 2014;Gu et al 2019), a wide clustered distribution of some typical species at small scales (Nguyen et al 2016), or a significantly smaller tree size of a minor species around the dominant species (Wiegand and Moloney 2013).…”

Species Association of the Dominant Tree Species in an Old-Growth Forest and Implications for Enrichment Planting for the Restoration of Natural Degraded Forest in Subtropical China

“…Information on species associations provides a theoretical basis for enrichment planting [51]. Additionally, the light requirement of tree species are also an important factor in species arrangement for enrichment planting [74,75]. Generally, tree species are grouped into shade-intolerant species, shade-tolerant species, and opportunistic species according to their light requirements [76,77].…”

Spatial patterns and associations of tree species at different developmental stages in a montane secondary temperate forest of northeastern China

“…The spatial patterns and associations of tree species would change with different growth stages of tree species ( Gu et al, 2019 ; Ledo, 2015 ; Zhou et al, 2019 ). Studies found that most species tended to be aggregated at seedling stage, while they tended to be regular or random at adult stage ( Condit et al, 2000 ; Getzin et al, 2006 ; Stoll & Bergius, 2005 ).…”

“…Currently, secondary forests have become a major forest type in many regions worldwide ( Brown & Lugo, 1990 ; Finegan, 1996 ); they account for 70% of the natural forests in northeastern China ( Yang et al, 2010 ). Research on spatial patterns and associations of tree species at different developmental stages may be informative in understanding the structure and dynamic processes of secondary forests ( Gu et al, 2019 ). In this study, we analyzed spatial patterns and associations of tree species at different developmental stages (seedling, sapling and adult) in a montane secondary forest of eastern Liaoning Province, China.…”