Effects of Tree Size, Shade Tolerance, and Spatial Pattern on the Mortality of Woody Plants in a Seminatural Forest in Central Kentucky

Abstract

Previous biogeographical research has investigated the mortality of woody plants, emphasizing tree size, shade tolerance, and competition individually as critical factors. Few researchers, though, have empirically evaluated the simultaneous and relative importance of these three factors in a single study. Based on a thirty-five-year study within the University of Kentucky Arboretum, we report that none of the factors exerted an overriding influence on the tree survivorship alone. Rather, they were tightly intertwined in a complex way. Our study indicates that the three factors have contributed perhaps equally or at least simultaneously to the overall demographic processes in the woodland.

过往的生物地理学研究, 已探讨了木本植物的死亡率, 并强调树木大小、耐阴性与竞争各别作为关键因素。但却鲜少有研究者在单一研究中, 就经验评估这三项因素同时发生且相对的重要性。我们根据一个在肯塔基大学植物园为期三十五年的研究, 记录这三项因素中, 没有任何一项对树木的存活率单独产生压倒性的影响。反之, 它们是以复杂的方式紧密地相互交织。我们的研究显示, 这三项因素大约均等地、或至少是同时地导致了林地的总体统计过程。

La investigación biogeográfica previa ha estudiado la mortalidad de plantas leñosas, haciendo énfasis en la talla del árbol, tolerancia a la sombra y competencia individual como factores críticos. No obstante, pocos investigadores han evaluado empíricamente la simultaneidad e importancia relativa de estos tres factores en un solo estudio. Basados en un estudio de treinta y cinco años dentro del Arboretum de la Universidad de Kentucky, podemos informar que ninguno de los factores ejerció de manera individual una influencia predominante para la supervivencia del árbol. Mejor, esos factores estuvieron firmemente entrelazados de modo complejo. Nuestro estudio indica que los tres factores han contribuido quizás equitativamente, o por lo menos simultáneamente, en los procesos demográficos generales en el arbolado.

Key Words:

• competition
• plant survivorship
• Ripley's K-function
• spatial point pattern analysis

关键词:

• 竞争
• 植物存活率
• 雷普利的K函数
• 空间点分佈形态分析。

Palabras clave:

• competencia
• supervivencia de la planta
• función K de Ripley
• análisis espacial de patrones de puntos

Acknowledgments

The authors thank Todd Rounsaville at the University of Kentucky Arboretum for permission and exchange of information about the woodland. Two anonymous reviewers provided valuable comments on the original version of the article. Daehyun Kim appreciates the unending support and encouragement of Soohyun Jung, William H. Kim, and Elizabeth S. Kim. Catherine Brereton, from the University of Kentucky Writing Center, provided English editing services.

Additional information

Notes on contributors

Daehyun Kim

DAEHYUN KIM is an Associate Professor in the Department of Geography at the University of Kentucky, Lexington, KY 40506. E-mail: [email protected]. His research focus is biogeophysical complexity in which spatial and temporal patterns of vegetation and soil are molded in dynamic, complex relationships with landform, climate, and hydrology.

Julian J. N. Campbell

JULIAN J. N. CAMPBELL is a consultant with the one-man company Bluegrass Woodland Restoration Center, Lexington, KY 40517. E-mail: [email protected]. His research focus is botany and plant ecology in Kentucky plus adjacent states, with special interest in the original condition of more eutrophic landscapes before settlement.