* Documentation of the degree and direction of effects of ozone on transpiration of canopies of mature forest trees is critically needed to model ozone effects on forest water use and growth in a warmer future climate. * Patterns of sap flow in stems and soil moisture in the rooting zones of mature trees, coupled with late-season streamflow in three forested watersheds in east Tennessee, USA, w...

Root elongation was measured in mature Eucalyptus pauciflora Sieber ex Sprengel subsp. pauciflora trees in a high-elevation stand, and in seedlings of E. pauciflora and E. nitens (Deane & Maiden) grown in a glasshouse. Elongation of non-mycorrhizal roots (>10 mm long) was measured at 0600 and 1800 h on several consecutive days. Root elongation of seedlings of both species in the glasshouse was ...

Selection cutting is a treatment that emulates tree-by-tree replacement for forests with uneven-age structures. It creates small openings in large areas and often generates a more homogenous forest structure (fewer large leaving trees and defective trees) that differs from old-growth forest. In this study, we evaluated whether this type of harvesting has an impact on genetic diversity of sugar ...

Arizona sycamore (Platanus wrightii: Platanaceae) is a riparian tree of the southwestern United States and adjacent Mexico. It is failing to reproduce in certain canyons where mature, seed-producing trees of this species occur. Three hypotheses were tested to explain this reproductive failure: I) the presence of domestic cattle prevents reproduction, 2) seeds produced in certain canyons are inv...

The Asian citrus psyllid (ACP), Diaphorina citri Kuwayama, is the key pest of citrus wherever it occurs due to its role as vector of huanglongbing (HLB) also known as citrus greening disease. Insecticidal vector control is considered to be the primary strategy for HLB management and is typically intense owing to the severity of this disease. While this approach slows spread and also decreases s...

Mature and old-growth forests (collectively “mature”) larger trees are important carbon sinks that declining worldwide. Information on the value of mature in United States has policy relevance for complying with President Joe Biden’s Executive Order 14072 directing federal agencies to define conduct an inventory them conservation purposes. Specific metrics related maturity can help land manager...

To recover verticality after disturbance, angiosperm trees produce 'tension wood' allowing them to bend actively. The driving force of the tension has been shown to take place in the G-layer, a specific unlignified layer of the cell wall observed in most temperate species. However, in tropical rain forests, the G-layer is often absent and the mechanism generating the forces to reorient trees re...

D oes genotypic variation in leaf form and function among tree species reflect adult height or only the seedling regeneration niche? For trees in closed canopy forests, typical adult tree height directly indicates the position of the species in the light hierarchy of the canopy. However, it is unknown whether trees that characteristically differ in mature height have similar or different canopy...

Decline of sugar maple in North American forests has been attributed to changes in soil calcium (Ca) and nitrogen (N) by acidic precipitation. Although N is an essential and usually a limiting factor in forests, atmospheric N deposition may cause N-saturation leading to loss of soil Ca. Such changes can affect carbon gain and growth of sugar maple trees and seedlings. We applied a 22 factorial ...

Increased dieback in Westland rata (Metrosideros umbellata) kamahi (Weinmannia racemosa) forests has been linked to the build-up of populations of the Australian brush-tailed possum (Trichosurus vulpecula). Within these forests young even-aged stands are observed to be more resilient to dieback than older stands. The effect of possum browsing on individual rata trees was related to the level of...