Seedling Recruitment

Abstract

Processes operating during the seed, seedling and juvenile phases are crucial for understanding patterns, dynamics and succession in plant communities (Schupp 1990; Grime and Hillier 1992). Many recent studies in temperate forests have emphasized the difficulties seedlings encounter in establishing themselves and the problems hardwood tree species face for survival, in particular the species of the genus Quercus (Lorimer 1984; Ross et al. 1986; Crow 1988, 1992; Johnson 1992; Keeley 1992; Ward 1992). This apparent paradox presented by late-successional species which, while dominant in the landscape, do not regenerate easily has long been noticed (Crow 1988), but the reasons for this are still poorly understood. The reasons for failure to recruit may include many factors, such as adequacy of seed dispersal (McClanahan 1986; Willson 1992), seed predation by animals (Crawley 1992), abiotic stresses such as drought or light limitation (Pons 1992; Espelta et al. 1995), and availability of suitable microsites for seed germination and seedling establishment (Crawley 1990). Furthermore, the regeneration failure of recent oak forests has also been attributed to the fact that the distribution of oaks overlaps to a large extent zones of intense human activity and thus oak forests have suffered from human impact (Matsuda et al. 1989).