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Mechanism Underlying the Spatial Pattern Formation of Dominant Tree Species in a Natural Secondary Forest.

Jia G, Yu X, Fan D, Jia J - PLoS ONE (2016)

Bottom Line: No correlation was found between the spatial pattern of soil conditions and that of trees.Both positive and negative intra- and interspecific relationships were found between different DBH classes at various distances.Large trees did not show systematic inhibition of the saplings.

View Article: PubMed Central - PubMed

Affiliation: Key Lab of Soil and Water Conservation and Desertification Combating, Ministry of Education, College of Soil and Water Conservation, Beijing Forestry University, Haidian District, Beijing, PR China.

ABSTRACT
Studying the spatial pattern of plant species may provide significant insights into processes and mechanisms that maintain stand stability. To better understand the dynamics of naturally regenerated secondary forests, univariate and bivariate Ripley's L(r) functions were employed to evaluate intra-/interspecific relationships of four dominant tree species (Populus davidiana, Betula platyphylla, Larix gmelinii and Acer mono) and to distinguish the underlying mechanism of spatial distribution. The results showed that the distribution of soil, water and nutrients was not fragmented but presented clear gradients. An overall aggregated distribution existed at most distances. No correlation was found between the spatial pattern of soil conditions and that of trees. Both positive and negative intra- and interspecific relationships were found between different DBH classes at various distances. Large trees did not show systematic inhibition of the saplings. By contrast, the inhibition intensified as the height differences increased between the compared pairs. Except for Larix, universal inhibition of saplings by upper layer trees occurred among other species, and this reflected the vertical competition for light. Therefore, we believe that competition for light rather than soil nutrients underlies the mechanism driving the formation of stand spatial pattern in the rocky mountainous areas examined.

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Related in: MedlinePlus

Statistics of trees in each DBH and height interval and the corresponding relationship between DBH and height (embedded) for the four dominant species.
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pone.0152596.g002: Statistics of trees in each DBH and height interval and the corresponding relationship between DBH and height (embedded) for the four dominant species.

Mentions: The stand was forested predominantly with Populus davidiana, Betula platyphylla, Larix gmelinii and Acer mono. A non-uniform distribution was observed for the dominant species at different life stages (Fig 1). On an average level, Larix was taller and larger than the other three species (Table 1); the quantity composition also showed that the height and DBH peaks of Larix were biased towards the upper end (Fig 2). Populus and Betula were similar in average height and DBH (Table 1), but in contrast to the single DBH and height distribution peak of Populus, a double peak was observed for Betula with one at 2–6 cm and the other at 14–18 cm (Fig 2). The Acer population was mainly composed of small individuals (Table 1 and Fig 2). For all species, the height increased exponentially with DBH (Fig 2 embedded). In contrast to the other three species, however, the height of Acer had not reached the maximum.


Mechanism Underlying the Spatial Pattern Formation of Dominant Tree Species in a Natural Secondary Forest.

Jia G, Yu X, Fan D, Jia J - PLoS ONE (2016)

Statistics of trees in each DBH and height interval and the corresponding relationship between DBH and height (embedded) for the four dominant species.
© Copyright Policy
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4814042&req=5

pone.0152596.g002: Statistics of trees in each DBH and height interval and the corresponding relationship between DBH and height (embedded) for the four dominant species.
Mentions: The stand was forested predominantly with Populus davidiana, Betula platyphylla, Larix gmelinii and Acer mono. A non-uniform distribution was observed for the dominant species at different life stages (Fig 1). On an average level, Larix was taller and larger than the other three species (Table 1); the quantity composition also showed that the height and DBH peaks of Larix were biased towards the upper end (Fig 2). Populus and Betula were similar in average height and DBH (Table 1), but in contrast to the single DBH and height distribution peak of Populus, a double peak was observed for Betula with one at 2–6 cm and the other at 14–18 cm (Fig 2). The Acer population was mainly composed of small individuals (Table 1 and Fig 2). For all species, the height increased exponentially with DBH (Fig 2 embedded). In contrast to the other three species, however, the height of Acer had not reached the maximum.

Bottom Line: No correlation was found between the spatial pattern of soil conditions and that of trees.Both positive and negative intra- and interspecific relationships were found between different DBH classes at various distances.Large trees did not show systematic inhibition of the saplings.

View Article: PubMed Central - PubMed

Affiliation: Key Lab of Soil and Water Conservation and Desertification Combating, Ministry of Education, College of Soil and Water Conservation, Beijing Forestry University, Haidian District, Beijing, PR China.

ABSTRACT
Studying the spatial pattern of plant species may provide significant insights into processes and mechanisms that maintain stand stability. To better understand the dynamics of naturally regenerated secondary forests, univariate and bivariate Ripley's L(r) functions were employed to evaluate intra-/interspecific relationships of four dominant tree species (Populus davidiana, Betula platyphylla, Larix gmelinii and Acer mono) and to distinguish the underlying mechanism of spatial distribution. The results showed that the distribution of soil, water and nutrients was not fragmented but presented clear gradients. An overall aggregated distribution existed at most distances. No correlation was found between the spatial pattern of soil conditions and that of trees. Both positive and negative intra- and interspecific relationships were found between different DBH classes at various distances. Large trees did not show systematic inhibition of the saplings. By contrast, the inhibition intensified as the height differences increased between the compared pairs. Except for Larix, universal inhibition of saplings by upper layer trees occurred among other species, and this reflected the vertical competition for light. Therefore, we believe that competition for light rather than soil nutrients underlies the mechanism driving the formation of stand spatial pattern in the rocky mountainous areas examined.

Show MeSH
Related in: MedlinePlus