Species-specific spatial structure, species coexistence and mortality pattern in natural, uneven-aged Scots pine (Pinus sylvestris L.)-dominated forest

Abstract

alder and common birch, the initial aggregated pattern was maintained over the examined 14-year period of the forest succession. Bivariate analysis showed that the most common interspecific association between pairs of tree species was spatial segregation (pine vs. alder, alder vs. birch and oak vs. birch) followed by spatial independence (pine vs. oak and oak vs. alder). The positive association was stated only for pine and birch and only for certain spatial scales (> 5 m). Simultaneously, at small distances they showed reciprocal repulsion. Changes in spatial relationships between tree species were negligible over 14-year period of forest succession. Our results confirmed the density-dependent mortality process in the uneven-aged Scots pine-dominated forest over 14-year period of forest development. Our study showed that spatial interactions between individuals along with speciesspecific ecological requirements should be incorporated into realistic models of forest development, helping to manage the forest ecosystems toward their greater structural complexity.

Stand dynamics in natural Scots pine forests as a model for adaptation management?

“…The diameter structure in the shape of the Liocourt curve is also referred to as typical for the close to nature stands of other tree species (Král et al, 2010;Sagheb-Talebi et al, 2015). A similar left-tailed distribution as on our plots reported Szmyt and Tarasiuk (2018) from the pine forests in Poland. Their work shows clearly the increase in the thickness of the individuals on the research plots during the 14year period, which correlates with the decrease of their number.…”

Spatial Pattern and Competitive Relationships of Moso Bamboo in a Native Subtropical Rainforest Community

“…To investigate whether the spatial pattern of MB and NTs would become more regularly distributed during bamboo expansion (hypothesis 2), we used the univariate distance pair correlation function g(r), which is based on the expected number of tree individuals (i.e., MB or NT) found at a distance r from an arbitrary point divided by the intensity λ of the pattern [31,33,34]; the function can be calculated as follows [34,36]:…”

“…where ρ(r) is the second-order characteristic density and λ is the intensity of the process. When g(r) = 1, the basic spatial pattern of MB and NTs was complete spatial randomness (CSR), whereas g(r) > 1 indicates aggregation, and g(r) < 1 indicates regularity [35,36]. Due to the rapid expansion of moso bamboo and the slightly heterogeneous environment in our plots, the tree intensity of MB and NTs in the three research plots was not approximately constant; our plots were partly affected by first-order heterogeneity (Figure 1).…”

“…Due to the rapid expansion of moso bamboo and the slightly heterogeneous environment in our plots, the tree intensity of MB and NTs in the three research plots was not approximately constant; our plots were partly affected by first-order heterogeneity (Figure 1). In such a situation, we implemented a null model based on a heterogeneous Poisson process [30,31,35,36]; thus, the intensity λ was not approximately constant, but varied with the spatial location coordinates (x,y). We used a moving window with a fixed bandwidth R = 5 to estimate λ(x,y) [31,35].…”

“…Strong competition may cause individuals close to each other to die, especially in more crowded environments. In this situation, random thinning could result in a more regular spatial pattern than normally observed during early succession [29,33,35,36]. Competition may at times not be strong enough to cause high mortality but rather lead to a reduction in tree size (e.g., height or diameter at breast height (DBH)).…”