Effect of competition on spatial patterns of oak forests on the Chinese Loess Plateau

Abstract

Reforestation or natural forest regeneration is an alternative measure for controlling soil erosion in degraded land on the Chinese Loess Plateau (CLP). However, our understanding of the temporal dynamics and the spatial patterns of forest regeneration remains inadequate. Two oak forests at different development stages were investigated to determine the spatial patterns of competitions (intraspecies and interspecies) during different successional stages. The intraspecies and interspecies spatial relationships among different tree diameters at breast height were analyzed at multiple scales by Kriging interpolation method and univariate and bivariate O-ring statistics. Our analytical results indicated that self-correlation and competition intensity were relatively high between oak and pine trees in the early development stage of oak forests due to their clumped distributions of heavy seeds. Birch trees had a lower competition in comparison to oak trees although birch was the dominant species. Therefore, asymmetric competition of oak trees was most likely to have led to their edge dispersal and their success in replacing the pioneer species. Asymmetric competition means that larger individuals obtained a disproportionately large share of the resources and suppressed the growth of smaller individuals. Kriging interpolation analysis showed a tendency towards homogenization caused by interspecies competition during the succession of oak forests. Our results demonstrated that the competition was the driving factor in the spatial distribution of oak forests on the CLP.

Competition Influences Tree Dimension, Biomass Distribution, and Leaf Area Index of Eucalyptus Urophylla in Dryland Ecosystems at East Nusa Tenggara

“…In this study, the competition between the subject tree and competitor trees was estimated by Hegyi index (McTague and Weiskittel, 2016). This parameter is commonly used to calculate the competition level among trees in various forest ecosystems (Ledermann and Stage, 2001, Das et al, 2011, Fraver et al, 2014, Kang et al, 2017. The Hegyi index was selected to quantify the competition given that it is simpler than the other parameters, wherein the competition between the subject tree and competitor trees was calculated based on their diameter and distance (Maleki et al, 2015).…”

Distribuição Espacial De Espécies Vegetais No Topsoil: Implicações Na Recuperação De Áreas Mineradas

“…Mesmo M. minutiflora não apresentando ameaça iminente à distribuição da flora nativa da área de estudo deste trabalho, existe uma preocupação com relação à possibilidade de expansão desta espécie, devido sua alta capacidade reprodutiva (CARMONA; MARTINS, 2010). Adicionalmente, casos de substituição de espécies invasoras sobre a população nativa levam ao aumento da competição interespecífica e diminuição da população substituída (DI et al, 2017).…”

Competition, spatial pattern, and regeneration of Haloxylon ammodendron and Haloxylon persicum communities in the Gurbantunggut Desert, Northwest China

“…Zhang et al (2016) also investigated the intraspecific and interspecific competition intensities of the rare and endangered tree Parrotia subaequalis in Wanfo Mountains Nature Reserve, Anhui Province of China, and found that interspecific competition was the main source of competitive intensity for the P. subaequalis population. Kang et al (2017) studied reforestation and natural forests on the Loess Plateau in China and found that competition was the driving factor in the spatial distribution of oak forests. Xu and Liu (2018) studied the endangered plant Acer catalpifolium in Sichuan Province of China and found that A. catalpifolium competition was mainly from interspecific sources.…”