Competition, mortality, and development of spatial patterns in two Cantabrian populations of <i>Fagus sylvatica</i> L. (Fagaceae)

Abstract

Oviedo (Asturias). Resumen ROZAS, V. & J.A. FERNÁNDEZ PRIETO (2000). Competencia, mortalidad y desarrollo de los patrones espaciales en dos poblaciones cantábricas de Fagus sylvatica L. (Fagaceae). Anales Jard. Bot. Madrid 58(1): 117-131 (en inglés).En el presente trabajo se analizan las distribuciones espaciales de tamaño y mortalidad en poblaciones de haya (Fagus sylvatica L.) incluidas en dos parcelas de bosque atlántico. En general, el crecimiento radial de F. sylvatica es directamente proporcional al tamaño e inversamente proporcional a la competencia intraespecífica, mientras que la mortalidad parece estar condicionada por competencia con individuos de la misma especie. La población formada sobre todo por árboles coetáneos presenta características espaciales indicativas de una intensa competencia intraespecíñca entre árboles vecinos, como lo son la ausencia de una distribución ordenada de tamaños, regularidad local de los árboles vivos y un patrón regular en los árboles dominantes. La población incluida en bosque maduro presenta una disposición ordenada de los tamaños, resultante de una extensa repulsión entre árboles pertenecientes a distintas cohortes. En esta población, la mayoría de la mortalidad tiene lugar dentro del denso grupo de individuos pequeños, produciendo regularidad en las hayas supervivientes. El patrón aleatorio de las hayas dominantes puede ser explicado por la actuación de factores exógenos o de procesos de autoatenuación.Palabras clave: Fagaceae, Fagus sylvatica L., dinámica forestal, patrón espacial, autocorrelación espacial, estructura de edad, competencia, mortalidad. In this paper the spatial patterns of size and mortality of European beech (Fagus sylvatica L.) were analy sed in two deciduous forest plots of Northern Spain. ¿i general terms, radial growth of F. sylvatica yields a direct relationship with size and an inverse relation with intraspecific competition while tree mortality seems be related to intraspecific competition. In the overall even-aged population, a lack of a recognisable structure in tree-size distribution, a small-scale regularity of survivors, and a regular pattern of dominant trees was noü'ced. This is a consequence of intense intraspecific competition at local level. In the old-growth plot, the wide repulsión between small and large beeches yields a specific spatial structure in tree-size distribution, showing even-sized groups of trees in different stages. Mortality in this plot occurs mainly within the dense group of small trees, which produces a broad regular pattern among the li ve beech trees. The random spatial pattern of dominant beeches seems to be characteristic of old-growth forests and could be a consequence of either self-thinning processes or exogenous factors.

Spatial pattern of beech (Fagus sylvatica L.) and oak (Quercus pubescens Mill.) seedlings in natural pine (Pinus sylvestris L.) woodlands

“…This result is in accordance with most studies finding that animal-dispersed species are clustered (for endozoochorous species, see Herrera and Jordano 1981;Jordano and Godoy 2002; and for synzoochorous species, see Hulme 2002). To our knowledge there has been no study of the spatial distribution of beech seedlings (for study of adult trees, see Szwagrzyk and Czerwczak 1993;Rozas and Fernandez Prieto 2000). Lookingbill and Zavala (2000; for Q. pubescens and Q. ilex) and Frost and Rydin (2000; for Q. robur) demonstrated an aggregation of seedlings in coniferous forests.…”

Fifty year record of change in tree spatial patterns within a mixed deciduous forest

“…Opposed to this are processes that tend to create mosaics and clumped distributions. These processes are influenced by microsite mosaics and canopy gaps (Peterson and Pickett, 1990;Runkle, 1982;Armesto et al, 1986) and stand history (Hessburg et al, 2000;Rozas and Prieto, 2000;Busing 1991). Gap-phase regeneration and small-scale changes create a variety of favourable microsites that might result in clumped spatial patterns (Beatty, 1984;Stewart, 1989).…”

Estimating the sustainable harvesting and the stable diameter distribution of European beech with projection matrix models

“…These natural mortalities, which depend mainly on tree age, intraspecific competition between trees located in close proximity [1], stand characteristics, and forestry practices, have been estimated from two sample plots, with areas 2500 and 3000 m 2 respectively, in a 110 ha beech forest in Cantabria (Northern Spain, near the study area) in 26.38% for the dbh class (2,4.9), 11.54% for the dbh class (5,9.9), 4.38% for the dbh class (10,29.9), and 1.43% for the dbh class (30,80) cm [28]. So, total harvest rates may be obtained by subtracting these natural mortalities from the harvest rates previously computed.…”