Structure and development of pitch canker infected Monterey pine stands at Año Nuevo, California

Abstract

The sustainability of indigenous Monterey pine (Pinus radiata D. Don) at Año Nuevo stands in the central coast of California was examined. The foremost management objective in these stands is to establish and maintain stand structures that ensure a sustainable presence of the species in terms of uneven-aged management. The major threats are the proliferation of shadetolerant tree species and the pitch canker (Fusarium circinatum) disease. The study was based on data from 17 systematically placed sample plots, measured once, in one stand with a very high degree of variation in stand structure and species composition. The results indicated that the sustainability of Monterey pine is not assured by existing stand structures. Monterey pine regeneration is almost completely lacking. Intensive shading and competition from high stand densities of shade-tolerant broadleaf trees are inhibiting regeneration, and growth of seedlings and saplings. Pitch canker is affecting growth, vigor, and competitive status of Monterey pine, but its progress and long-term impact remain unknown. Single tree or group selection cuttings, combined with treatments that enhance regeneration, are urgently required for the promotion of Monterey pine.

The Effect of Forest Management Options on Forest Resilience to Pathogens

“…This positive relationship between tree density and pathogen incidence or impact has been observed for a range of other tree and airborne pathogen species and locations, including crown dieback of F. excelsior due to H. fraxineus in forests across the Czech Republic (Havdova et al, 2017), mortality of P. sylvestris due to snow blight (Phacidium infestans) in Sweden (Burdon et al, 1992), and infection level by M. pinitorqua of both P. sylvestris in Southwest Lapland and in Northern Karelia, Finland (Mattila et al, 2001;Mattila, 2002), and P. pinaster in France (Desprez-Loustau and Wagner, 1997). However a number of other studies find no relationship between pathogen incidence and tree density (McCracken and Dawson, 1998;Bishaw et al, 2003;Piirto and Valkonen, 2005).…”

Overstory and shrub effects on natural regeneration processes in native Pinus radiata stands

“…International concern has risen over the conservation of these stands as genetic resources for native populations and international plantation culture (Rogers, 2002;Piirto and Valkonen, 2005). Yet, little is known about the regeneration conditions of native Monterey pine stands (Vogl et al, 1977;White, 1999).…”

“…Yet, little is known about the regeneration conditions of native Monterey pine stands (Vogl et al, 1977;White, 1999). Monterey pine research in the US has emphasized the epidemiology of pitch canker, with very little focus on Monterey pine ecology and native stand dynamics (Roy, 1966;Storer et al, 2002;Stephens et al, 2004;Piirto and Valkonen, 2005).…”

Growth and survival of lodgepole pine and Scots pine after 25 years in a reciprocal transplant experiment in Canada and Sweden

“…There are many examples of planned introductions of tree species that grow and perform well as exotics (Wang et al 2006a;Cubbage et al 2014;Verhaegen et al 2014). One example where, in addition, the productivity is much lower in the natural range is the introduction of Monterey pine (Pinus radiata D. Don) to large areas in Australia, New Zealand, Chile and Africa, where it makes a very strong contribution to the forest industry (Piirto & Valkonen 2005).…”