StatMod provides an easy-to-use and inexpensive tool for spatially applying the classification rules generated from the CT algorithm in S-PLUS. While the focus of this article was to use StatMod for classification trees, StatMod functions in a similar manner for regression trees. Classification trees are appropriate for discriminating distinct classes such as land cover. In a regression tree, t...

We sought to quantify changes in tree species composition, forest structure and aboveground forest biomass (AGB) over 76 years (1930-2006) in the deciduous Black Rock Forest in southeastern New York, USA. We used data from periodic forest inventories, published floras and a set of eight long-term plots, along with species-specific allometric equations to estimate AGB and carbon content. Between...

Questions: Do large, old Sequoiadondron giganteum trees respond to the creation of adjacent canopy gaps? Do other co-occurring tree species and younger S. giganteum adjacent to gaps also respond? What are the likely factors affecting growth responses? Location: Mixed-conifer forests of the southern Sierra Nevada, California, USA. Methods: We measured the growth response of large, old S. gigante...

Fire shapes the distribution of savanna and forest through complex interactions involving climate, resources and species traits. Based on data from central Brazil, we propose that these interactions are governed by two critical thresholds. The fire-resistance threshold is reached when individual trees have accumulated sufficient bark to avoid stem death, whereas the fire-suppression threshold i...

Thirty nests of Hammond’s (Empidonax hammondii) and 88 nests of Pacificslope (E. difficilis) Flycatchers were located in different-aged Douglas-fir (Pseudotsuga menziesii)/tanoak (Lithocarpus densiflorus) dominated forests at 12 study sites in northwestern California during the breeding seasons of 1984, 1985, 1987, and 1988. In contrast to Pacificslope Flycatchers, Hammond’s used nest trees tha...

We examined relationships between stem diameter, sapwood area, leaf area and transpiration in a 15-year-old mountain ash (Eucalyptus regnans F. Muell.) forest containing silver wattle (Acacia dealbata Link.) as a suppressed overstory species and mountain hickory (Acacia frigescens J.H. Willis) as an understory species. Stem diameter explained 93% of the variation in leaf area, 96% of the variat...

Germination provides many potentially unrecognized sources of variation in the regeneration niche. In this study we relate germination requirements and seed size for 16 species of pioneer trees to microclimatic conditions present in gaps in semi-deciduous rain forest in Panama. We found that, whereas increased duration of direct irradiance can be an effective indicator of the presence of a cano...

1. Trees present herbivorous insects with the greatest diversity of resources any plant growth form. Both ontogeny and shading can alter suitability for arboreal insect herbivores. 2. We conducted a longitudinal study tagged ‘mature’ (>12 months old) Eucalyptus camaldulensis leaves to compare understorey canopy trees leaf senescence-inducing psyllid, Cardiaspina albitextura. quantified sugars t...