Biomass and productivity of the woody strata of forested bogs in northern Minnesota

1985 ◽  
Vol 63 (12) ◽  
pp. 2416-2424 ◽  
Author(s):  
D. F. Grigal ◽  
C. G. Buttleman ◽  
L. K. Kernik
Keyword(s):  
Primary Productivity ◽  
Net Primary Productivity ◽  
Nutrient Status ◽  
Forest Growth ◽  
Growth And Yield ◽  
Aboveground Net Primary Productivity ◽  
Yield Model ◽  
Raised Bogs ◽  
Aboveground Productivity ◽  
Aboveground Production

Biomass and net primary productivity of three forested perched and three forested raised ombrotrophic bogs were determined and compared. The tree stratum was dominated by Picea mariana (Mill.) B.S.P. and the low shrub stratum by Ledum groenlandicum Oeder and Chamaedaphne calyculata (L.) Moench. Based on a modified forest growth and yield model (STEMS), aboveground living biomass of the tree stratum on the perched bogs was declining by about 0.5 t ha−1 year−1 from a base of 100.7 t ha−1, and on the raised bogs it was increasing by 0.2 t ha−1 year−1 on a base of 31.0 t ha−1. Net primary productivity of that stratum was 3.1 and l.0 t ha−1 year−1 on the perched and raised bogs, respectively. Low shrub aboveground productivity, equal to mortality, was 0.4 and 2.0 t ha−1 year−1 on the perched and raised bogs, respectively. This was about 40% of the standing biomass of shrubs in both bog types. Aboveground net primary productivity of woody strata was 3.5 and 3.0 t ha−1 year−1 on the perched and raised bogs, respectively. These data are comparable to earlier estimates of Sphagnum production on the same bogs: 3.8 t ha−1 year−1 on perched bogs and 3.2 t ha−1 year−1 on raised bogs. Vascular herbs contributed an additional 0.2 t ha−1 year−1 to aboveground production on the perched bogs and 0.1 t ha−1 year−1 on the raised bogs. The higher productivity of perched bogs is probably related to slightly higher nutrient status related to their landscape position. The total productivity of all strata of these ombrotrophic sites approaches that of upland sites in the same region.

Elemental dynamics in forested bogs in northern Minnesota

1991 ◽  
Vol 69 (3) ◽  
pp. 539-546 ◽  
Author(s):  
D. F. Grigal
Keyword(s):  
Primary Productivity ◽  
Plant Uptake ◽  
Net Primary Productivity ◽  
Nutrient Status ◽  
Landscape Position ◽  
Mineralization Rate ◽  
Annual Plant ◽  
Raised Bogs ◽  
Elemental Mass ◽  
Surface Peat

Dynamics of nitrogen (N), phosphorus (P), potassium (K), calcium (Ca), and magnesium (Mg) were determined for three perched bogs, formed by lake filling, and three raised bogs, formed by landscape swamping. N and K concentrations were higher in the undergrowth of perched bogs, and Ca and Mg concentrations were higher in subsurface anaerobic peat of raised bogs. Elemental pools in vegetation were in the order N > Ca > K > Mg > P; in surface peat, N > Ca > Mg > P = K. Differences in elemental mass between the bog types were closely related to biomass differences. The atmosphere potentially supplied from 3% of annual plant uptake of K to 20% of Mg; this fraction was inversely related to uptake as a proportion of the surface peat. Vegetation on raised bogs had a greater proportion of uptake from the atmosphere (15 vs. 12%), a faster rate of elemental turnover (3.8 vs. 4.8 years), and lower net primary productivity (NPP) than on perched bogs, all indicative of a lower nutrient status. The annual mineralization rate of the surface peat for both bog types was estimated at 1.5% year−1; NPP predicted from N mineralized at this rate agrees well with observations. The better nutritional status of perched bogs may be related to landscape position, with potential inputs via runoff from adjacent uplands. The nutrient capital in both bog vegetation and substrate was similar to that in upland northern conifer forests. Key words: acrotelm, ombrotrophic, raised bogs, nutrients, peatlands, nutrient cycling.

scholarly journals Annual Aboveground Production and Consumption by Large Mammalian Herbivores in the Northern Range of Yellowstone National Park

1989 ◽  
Vol 13 ◽  
pp. 183-185
Author(s):  
Douglas Frank ◽  
S. McNaughton
Keyword(s):  
Primary Productivity ◽  
National Park ◽  
Net Primary Productivity ◽  
Ecosystem Processes ◽  
Aboveground Net Primary Productivity ◽  
Mammalian Herbivores ◽  
Nutrient Flows ◽  
Production And Consumption ◽  
Aboveground Production ◽  
Large Populations

The principal objectives of this study are to measure aboveground net primary productivity and consumption by large mammalian herbivores in Yellowstone's northern range. The significance of such information is two-fold. Firstly, it will provide a "pulse rate" of ecosystem processes in an integral region of the Yellowstone Ecosystem and a comparison of rates of energy and nutrient flows with other ecosystems worldwide. This is of particular ecological interest, since such data for areas supporting large populations of free­ranging native herbivores are rare. Secondly, these data will provide a greater understanding of the effects of ungulate use on ecosystem function in Yellowstone, and thereby, an assessment of current park management of ungulate populations.

scholarly journals Stand-Level Components of a Growth and Yield Model for Nothofagus Mixed Forests from Southern Chile

Forests ◽  
2020 ◽  
Vol 11 (8) ◽  
pp. 810
Author(s):  
Sebastian Palmas ◽  
Paulo C. Moreno ◽  
Wendel P. Cropper ◽  
Alicia Ortega ◽  
Salvador A. Gezan
Keyword(s):  
Forest Type ◽  
Geographical Area ◽  
Basal Area ◽  
Forest Growth ◽  
Model Systems ◽  
Growth And Yield ◽  
Permanent Plots ◽  
Stand Age ◽  
Yield Model ◽  
Mixed Forests

Reliable information on stand dynamics and development is needed to improve management decisions on mixed forests, and essential tools for this purpose are forest growth and yield (G&Y) models. In this study, stand-level G&Y models were built for cohorts within the natural mixed second-growth Nothofagus-dominated forests in Chile. All currently available (but limited) data, consisting of a series of stratified temporary and permanent plots established in the complete range of this forest type, were used to fit and validate these models. Linear and nonlinear models were considered, where dominant stand age, number of trees, and the proportion of basal area of Nothofagus species resulted in significant predictors to project future values of stand basal area for the different cohorts (with R2 > 0.51 for the validation datasets). Mortality was successfully modeled (R2 = 0.79), based on a small set of permanent plots, using the concept of self-thinning with a proposed model defined by the idea that, as stands get closer to a maximum density, they experience higher levels of mortality. The evaluation of these models indicated that they adequately represent the current understanding of dynamics of basal area and mortality of Nothofagus and companion species in these forests. These are the first models fitted over a large geographical area that consider the dynamics of these mixed forests. It is suggested that the proposed models should constitute the main components of future implementations of G&Y model systems.

scholarly journals Impact of Extreme Weather Events on Aboveground Net Primary Productivity and Sheep Production in the Magellan Region, Southernmost Chilean Patagonia

Geosciences ◽  
2020 ◽  
Vol 10 (8) ◽  
pp. 318
Author(s):  
Pamela Soto-Rogel ◽  
Juan-Carlos Aravena ◽  
Wolfgang Jens-Henrik Meier ◽  
Pamela Gross ◽  
Claudio Pérez ◽  
...  
Keyword(s):  
Primary Productivity ◽  
Net Primary Productivity ◽  
Extreme Weather ◽  
Extreme Weather Events ◽  
Maximum Temperature ◽  
Aboveground Net Primary Productivity ◽  
Weather Events ◽  
Chilean Patagonia ◽  
Magellan Region ◽  
Sheep Production

Spatio-temporal patterns of climatic variability have effects on the environmental conditions of a given land territory and consequently determine the evolution of its productive activities. One of the most direct ways to evaluate this relationship is to measure the condition of the vegetation cover and land-use information. In southernmost South America there is a limited number of long-term studies on these matters, an incomplete network of weather stations and almost no database on ecosystems productivity. In the present work, we characterized the climate variability of the Magellan Region, southernmost Chilean Patagonia, for the last 34 years, studying key variables associated with one of its main economic sectors, sheep production, and evaluating the effect of extreme weather events on ecosystem productivity and sheep production. Our results show a marked multi-decadal character of the climatic variables, with a trend to more arid conditions for the last 8 years, together with an increase in the frequency of extreme weather events. Significant percentages of aboveground net primary productivity (ANPP) variance is explained by high precipitation, mesic temperatures, and low evapotranspiration. These conditions are, however, spatially distributed in the transition zone between deciduous forests and steppe and do not represent a general pattern for the entire region. Strong precipitation and wind velocity negatively affect lamb survival, while temperature and ANPP are positively correlated. The impact of extreme weather events on ANP and sheep production (SP) was in most of the cases significantly negative, with the exception of maximum temperature that correlated with an increase of ANPP, and droughts that showed a non-significant negative trend in ANPP. The examination of these relationships is urgent under the current scenario of climate change with the acceleration of the environmental trends here detected.

A simple growth and yield model for assessing changes in standing volume across Canada’s forests

2009 ◽  
Vol 85 (1) ◽  
pp. 57-64 ◽  
Author(s):  
C -H. Ung ◽  
P Y Bernier ◽  
X J Guo ◽  
M -C. Lambert
Keyword(s):  
Predictive Power ◽  
Robust Regression ◽  
Forest Growth ◽  
Growth Potential ◽  
Growth And Yield ◽  
Stand Age ◽  
Yield Model ◽  
Wood Volume ◽  
National Model ◽  
Growth And Yield Models

We have adjusted two growth and yield models to temporary sample plots from across Canada, and used climate variables in lieu of phytometric indices such as site index to represent, in part, the site-level variability in growth potential. Comparison of predicted increments in plot-level height, basal area and merchantable wood volume to increments of these variables measured in permanent sample plots shows a moderate to poor predictive ability. Comparison with the performance of four operational growth and yield models from different provinces across Canada shows comparable predictive power of this new model versus that of the provincial models. Based on these results, we suggest that the simplification of regional growth and yield models may be achieved without further loss of predictive power, and that the large error in the prediction of growth increment is mostly associated with the use of temporary sample plots which, by definition, contain little information on stand dynamics. We also suggest that, because of the empirical nature of these growth and yield models, the scale of application should determine the appropriate scale of the model. National estimates of forest growth are therefore less likely to be biased if obtained from a national model only than if obtained from a combination of regional models, where those exist, gap-filled with estimates from a national model. Key words: yield model, merchantable wood volume, stand age, climatic variables, simultaneous regression, robust regression

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