Effects of ozone and climate on ponderosa pine (Pinusponderosa) growth in the Colorado Rocky Mountains

1993 ◽  
Vol 23 (9) ◽  
pp. 1750-1759 ◽  
Author(s):  
David L. Peterson ◽  
Michael J. Arbaugh ◽  
Lindsay J. Robinson
Keyword(s):  
Ponderosa Pine ◽  
Rocky Mountains ◽  
Basal Area ◽  
Dominant Factor ◽  
Front Range ◽  
Growth Trends ◽  
Second Growth ◽  
Colorado Rocky Mountains ◽  
Highly Correlated

Long-term radial growth trends of ponderosa pine (Pinusponderosa var. scopulorum) were studied in second-growth stands in the Front Range of the Colorado Rocky Mountains to determine if there has been any impact from oxidant air pollution. Although ozone concentrations are relatively high at some locations, visible pollutant injury was not found in any trees. Time series of basal area increments are generally homogeneous within stands. Concurrent periods of increasing and decreasing growth can be found in stands throughout the Front Range, which indicates that there are temporal growth trends at the regional level. Most of these trends appear to be related to the effects of stand dynamics and climate. Correlation analysis with climatic variables indicates that soil moisture supply is the dominant factor controlling interannual variation of basal area growth. Palmer hydrological drought index is highly correlated (positively) with growth during the summer months; total precipitation in spring is positively correlated with growth, and mean temperature in spring is negatively correlated with growth. There are no recent changes in growth trends that might be associated with elevated levels of ambient ozone in the Front Range.

scholarly journals Long-Term Seedfall, Establishment, Survival, and Growth of Natural and Planted Ponderosa Pine in the Colorado Front Range

2006 ◽  
Vol 21 (1) ◽  
pp. 19-26 ◽  
Author(s):  
Wayne D. Shepperd ◽  
Carleton B. Edminster ◽  
Stephen A. Mata
Keyword(s):  
Ponderosa Pine ◽  
Basal Area ◽  
Colorado Front Range ◽  
Initial Growth ◽  
Front Range ◽  
Natural Seedling ◽  
Survival And Growth ◽  
Seed Crops ◽  
Better Than

Abstract Seedfall, natural regeneration establishment, and growth of planted seedlings was observed from 1981 to 2001 under shelterwood and seedtree overstories in a replicated study in ponderosa pine in the Manitou Experimental Forest in the Colorado Front Range. Good seed crops were produced only every 4 to 6 years, with almost no viable seed produced in intervening years. With seed predation, only 14% of total seedfall was available for germination. Shelterwood overstories containing between 6 and 14 m2 ha−1 stem basal area over scarified seedbeds provided optimal conditions for natural seedling establishment. Survival and growth of planted seedlings was much better than that of natural seedlings. However, poor survival and slow initial growth may require many years to establish a fully stocked forest of natural seedlings.

Short-Term Impacts of Thinning Ponderosa Pine on Pandora Moth Densities, Pupal Weights, and Phenology

1995 ◽  
Vol 10 (3) ◽  
pp. 91-94
Author(s):  
Darrell W. Ross
Keyword(s):  
Pinus Ponderosa ◽  
Ponderosa Pine ◽  
Basal Area ◽  
Stand Density ◽  
Adult Emergence ◽  
Adult Density ◽  
Egg Hatch ◽  
Second Growth ◽  
Insect Phenology ◽  
Foliage Weight

Abstract Second-growth ponderosa pine (Pinus ponderosa) stands with outbreak populations of the pandora moth (Coloradia pandora) were thinned from below removing about half of the basal area. Thinning had no effect on pandora moth pupal density or weight, or emerging adult density in the following generation. However, adult emergence and egg hatch occurred 7-10 days earlier in thinned plots compared with unthinned plots. Egg and larval densities on a foliage weight basis were not significantly different between thinned and unthinned plots. Thinning stands infested with pandora moth will not significantly affect the course of an outbreak for at least one generation. Timing of direct controls for the pandora moth should consider the effect of stand density on insect phenology. West. J. Appl. For. 10(3):91-94.

scholarly journals Historic range of variability of mountain forest ecosystems: concepts and applications

2003 ◽  
Vol 79 (2) ◽  
pp. 223-226 ◽  
Author(s):  
Thomas T Veblen
Keyword(s):  
Case Studies ◽  
Ponderosa Pine ◽  
Rocky Mountains ◽  
Management Practices ◽  
Forest Ecosystems ◽  
Resource Planning ◽  
Climatic Variation ◽  
Mountain Forest ◽  
Historical Perspectives ◽  
Colorado Rocky Mountains

Concepts of historical range of variability (HRV) have taken on an increasingly important role in resource planning and the management of mountain forest ecosystems. This essay draws on examples from the study of the history of disturbance ecology in the Colorado Rocky Mountains and the southern Andes to examine key HRV concepts and their applications. These case studies show that historical perspectives can reduce the chances of major future surprises in ecosystem conditions related to climatic variation, which often overrides many of the effects of management practices. They demonstrate the long-lasting legacy effects of relatively infrequent but severe disturbances in the past that shaped the present landscape and its potential response to future climatic variation. Finally, the case studies illustrate the importance of conducting area-specific research in potential management areas rather than simply extrapolating research findings from studies of historic range of variability of forest ecosystems conducted elsewhere. Key words: climatic variation, disturbance, Rocky Mountains, Andes, Patagonia, Ponderosa pine, landscape, ecosystem management, fire

Growth trends of blue oak (Quercusdouglasii) in California

1993 ◽  
Vol 23 (8) ◽  
pp. 1720-1724 ◽  
Author(s):  
Jane A. Kertis ◽  
Rob Gross ◽  
David L. Peterson ◽  
Michael J. Arbaugh ◽  
Richard B. Standiford ◽  
...  
Keyword(s):  
Mediterranean Climate ◽  
Basal Area ◽  
Limited Data ◽  
Deep Soil ◽  
Coniferous Species ◽  
Growth Trends ◽  
Blue Oak ◽  
Soil Moisture Availability ◽  
High Precipitation

Long-term growth trends of blue oak (Quercusdouglasii Hook. & Arn.) at five sites in California were quantified and interpreted with respect to annual precipitation. Mean annual basal area increment (BAI) at sites with deep soil profiles or high precipitation was twice as great as growth at other sites. In general, BAI increased sharply during approximately the first 40 years of tree growth, then increased gradually or leveled off for the next 100 years. Limited data from older trees suggest that BAI decreases gradually after this point. Growth trends are relatively homogeneous within each site, but vary among sites. Most sites have relatively high correlations with precipitation compared with coniferous species at higher elevations. Interannual variation in soil moisture availability is clearly an important factor affecting annual growth of blue oak in the Mediterranean climate of California. This is the first known dendroecological study of blue oak growth trends.

Long-term, wintertime aerosol, cloud and precipitation measurements in the Northern Colorado Rocky Mountains, USA

2006 ◽  
Vol 82 (1-2) ◽  
pp. 194-202 ◽  
Author(s):  
Edward E. Hindman ◽  
Randolph D. Borys ◽  
Douglas H. Lowenthal ◽  
Neal Phillip
Keyword(s):  
Rocky Mountains ◽  
Aerosol Cloud ◽  
Northern Colorado ◽  
Colorado Rocky Mountains

scholarly journals New particle formation in the front range of the Colorado Rocky Mountains

2007 ◽  
Vol 7 (6) ◽  
pp. 15581-15617 ◽  
Author(s):  
M. Boy ◽  
T. Karl ◽  
A. Turnipseed ◽  
R. L. Mauldin ◽  
E. Kosciuch ◽  
...  
Keyword(s):  
Rocky Mountains ◽  
Cloud Condensation Nuclei ◽  
Measurement Data ◽  
Particle Growth ◽  
Particle Formation ◽  
Conclusive Evidence ◽  
Front Range ◽  
New Particle Formation ◽  
Particle Measurement ◽  
Colorado Rocky Mountains

Abstract. New particle formation is of interest because of its influence on the properties of aerosol population, and due to the possible contribution of newly formed particles to cloud condensation nuclei. Currently no conclusive evidence exists as to the mechanism or mechanisms of nucleation and subsequent particle growth. However, nucleation rates exhibit a clear dependence on ambient sulphuric acid concentrations and particle growth is often attributed to the condensation of organic vapours. A detailed study of new particle formation in the Front Range of the Colorado Rocky Mountains is presented here. Gas and particle measurement data for 32 days was analyzed to identify event days, possible event days, and non-event days. A detailed analysis of nucleation and growth is provided for four days on which new particle formation was clearly observed. Evidence for the role of sesquiterpenes in new particle formation is presented.

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