Regional growth changes in ozone-stressed ponderosa pine (Pinus ponderosa) in the Sierra Nevada, California, USA

Abstract

Basal area growth trends were determined for ponderosa pine (Pinus ponderosa) in the Sierra Nevada, California, USA, to: (1) evaluate long term growth patterns, and (2) determine if there has been any recent change in the frequency of growth changes outside the expected range of natural variability. Ponderosa pine was sampled in 56 stands with the sample divided equally between sites with and without documentation of symptomatic ozone injury. Basal area increment growth was calculated, temporal growth patterns were evaluated for each tree using time series analysis techniques, and changes in growth trends were summarized for each site by decade. There were several regional growth trends during this century, including a large number of growth decreases in the 1920s and a large number of increases in the 1930s. Many trends were synchronous within stands but were less frequently synchronous between stands. There were significant growth reductions since 1950 in some stands in the southern Sierra. These growth reductions occurred in areas with the highest levels of ozone exposure and needle injury. There was no evidence, however, of significant numbers of recent growth reductions for the entire Sierra Nevada region. Some sites had growth changes possibly associated with stand dynamics, management practices, and pathogens.

Concentraciones in situ de ozono en bosques de la Cuenca de México e influencia de la altitud

“…8 (44) 2006; Ferreti et al, 2007aFerreti et al, , 2007b y la disminución del crecimiento radial (Peterson et al, 1991;Somers et al, 1998). Otras invvestigaciones señalan efectos sobre el desarrollo del follaje de árboles de bosques templados; por ejemplo, clorosis foliar, caída prematura de acículas, seguido de un proceso de senescencia prematura, el cual culmina con la muerte parcial o total de los individuos en extensas áreas forestales (Miller et al, 1994;Grulke y Lee 1997;Skelly et al, 1997;Somers et al, 1998;Krupa, 1999;Hernández-Tejeda, 2014).…”

The Effects of Repeated Prescribed Burning on Pinus ponderosa Growth

“…Prescribed fires can reduce fuel loading, thereby reducing the probability of subsequent high intensity fires (Wagle and Eakle 1979, Covington and Sackett 1990, Ffolliott and Guertin 1990, Agee 1993. The damaging effects of fire on trees through crown, stem,and fineroot damage (Wyant et al1983, Ryan and Reinhardt 1988, Peterson and Arbaugh 1989,Ryan and Steele 1989, Ryan and Frandsen 1991, Peterson et a1 1991, Swezy and Agee 1991 must be balanced against the potential benefits of thinning and nuuient release on growth Sackett 1986, 1992;Harris and Covington 1983, Sutherland and Covington 1987,Oliver and Larson 1990, Sutherland et al 1991.…”

“…Most previous research on the effects of fire on conifers has focused on the relationship between physical injury and tree survival (Lynch 1959, Methven 1971, Dieterich 1979, Peterson and Arbaugh 1986, Wyant et al 1986, Ryan et a1 1988,Peterson and Arbaugh 1989. Several studies have examined the effect of prescribed burning on conifer growth, although the results vary widely.…”

Monitoring for ozone injury in West Coast (Oregon, Washington, California) forests in 1998.

“…Interestingly, fewer FHM biosites were located and established in southern California (where higher levels of ozone occur) than in northern California, perhaps owing to the difficulty in finding good biosites. Injury to pines in the Sequoia and Sierra National Forest plots is generally seen on 3-year-old or older needles, which indicates that symptoms are most visible only after injury has accumulated for several years (Peterson et al 1991). All FHM indicator plants, except ponderosa and Jeffrey pines, are deciduous; leaves therefore are exposed over only one growing season.…”

“…ex Laws. ), are sensitive to ozone at concentrations that normally occur over wide areas of the western landscape , Peterson et al 1991, US EPA 1996b. Because of the long life span of trees, there is ample opportunity for a long-term, cumulative effect on tree growth.…”