Forest dynamics and the growth decline of red spruce and sugar maple on Bolton Mountain, Vermont: a comparison of modeling methods
نویسندگان
چکیده
Montane forests in the northeastern United States have experienced symptoms of declining vigor, such as branch dieback and increased mortality, over the last half-century. These declines have been attributed to the cumulative impacts of acid deposition, but reconstructing these declines from tree-ring records has proved difficult because of confounding factors that affect low-frequency growth patterns, including climate and natural growth trajectories following disturbance. We obtained tree-ring records of red spruce (Picea rubens Sarg.) and sugar maple (Acer saccharum L.) from three elevations on Bolton Mountain, Vermont, and applied traditional dendroclimatological analyses that revealed a profound declining growth–climate correlation since ca. 1970 for sugar maple but much less so for red spruce. We then applied a new multifaceted statistical approach that conservatively detrends tree-ring records by minimizing the influences of tree size, age, and canopy disturbances on radial growth. In contrast with the traditional analysis, this approach yielded chronologies that were consistently correlated with climate but with important exceptions. Low-elevation sugar maple suffered distinct episodes of slow growth, likely because of insect defoliators, and also a progressive decline since ca. 1988. Red spruce experienced subdecadal episodes of decline that may be related to freeze–thaw events known to injure foliage but showed no evidence of a progressive decline. This analysis was supported by a forest plot resurvey that indicated major declines in
منابع مشابه
Nutrient Dynamics and Decomposition rate of Norway Spruce Needles in Stråsan and Lajim stands
Climate changes due to changes in a habitat leads to differences in the rate of decomposition and nutrient dynamics of leaflitters, which has many effects on the controlling factors of the decomposition process. In the present study, the rate of decomposition and nutrient dynamics of Norway spruce was evaluated for 363 days in the two forestation sites in the natural and foreign habitats, ...
متن کاملEffects of chronic ammonium sulfate treatment on the forest at the Bear Brook Watershed in Maine.
At the Bear Brook Watershed in Maine (BBWM), the forest tree composition was characterized and the effects of the chronic ammonium sulfate ((NH(4))(2)SO(4)) treatment on basal area growth, foliar chemistry, and gas exchange were investigated on forest species. The BBWM is a paired watershed forest ecosystem study with one watershed, West Bear (WB), treated since 1989 with 26.6 kg N ha(-1) year(...
متن کاملCommunity and population dynamics of spruce-fir forests on Whiteface Mountain, New York: recent trends, 1985-2000
We remeasured two sets of permanent plots in old-growth, spruce–fir forests on Whiteface Mountain to quantify ongoing vegetation dynamics at sites impacted by spruce decline. One set of plots was a stratified random sample of the vegetation in a subalpine watershed (Baldwin site). The other was selected to represent forest conditions in a high-elevation subset of the spruce–fir forest (Esther s...
متن کاملSimulated root dynamics of a 160-year-old sugar maple (Acer saccharum Marsh.) tree with and without ozone exposure using the TREGRO model.
Because of difficulties in directly assessing root responses of mature forest trees exposed to atmospheric pollutants, we have used the model TREGRO to analyze the effects of a 3- and a 10-year exposure to ozone (O(3)) on root dynamics of a simulated 160-year-old sugar maple (Acer saccharum Marsh.) tree. We used existing phenological, allometric, and growth data to parameterize TREGRO to produc...
متن کاملSugar maple growth in relation to nutrition and stress in the northeastern United States.
Sugar maple, Acer saccharum, decline disease is incited by multiple disturbance factors when imbalanced calcium (Ca), magnesium (Mg), and manganese (Mn) act as predisposing stressors. Our objective in this study was to determine whether factors affecting sugar maple health also affect growth as estimated by basal area increment (BAI). We used 76 northern hardwood stands in northern Pennsylvania...
متن کامل