Duncan Patten - Academia.edu (original) (raw)
Papers by Duncan Patten
The increasing responses to symposia devoted to riparian resources in the past decade have create... more The increasing responses to symposia devoted to riparian resources in the past decade have created a need to channel this enthusiasm into a permanent organization. The Arizona Riparian Council was formally organized in October 1986 to provide an annual forum for local coordination of management and research activities. In addition, the Council draws support from individuals representing management agencies, conservation groups, research institutions, and user groups. The importance of forming such local or regional groups is facilitating better communication on the local level, which may lead to greater advocacy of protecting riparian resources on a national level based on grass-roots support.
Rush Creek, which feeds Mono Lake, has been diverted below Grant Lake, totally or in part, for ov... more Rush Creek, which feeds Mono Lake, has been diverted below Grant Lake, totally or in part, for over 40 years. In the early 1980 ' s, because of above normal snow packs, runoff was released into the creek. Minimum flow releases have also been established. The riparian vegetation has responded to these releases. In a few areas, riparian trees and shrubs (e.g., black cottonwood and willow) survived the diversion period but with high stem mortality. These plants are resprouting in response to the 1980's floods. In other areas, new plants are establishing within the floodplain; however, on areas away from the floodplain most riparian plants died and are not regenerating. The patterns of riparian regeneration and environmental requirements of each riparian species have been preliminarily determined.
The restorative potential of dam removal on ecosystem function depends on the reversibility of th... more The restorative potential of dam removal on ecosystem function depends on the reversibility of the hydrogeomorphic effects of a dam and its operations. While dam removal is an established engineering practice, the long-term ecological response remains speculative. We used paleoflood hydrology, topographic surveys, hydrologic modeling (HEC-RAS), and aerial photograph interpretation to investigate the long-term hydrogeomorphic and ecologic responses to dam failure and removal. We compared downstream hydroecological responses of a controlled dam removal, which used natural sediment removal (Mystic Lake Dam in 1985), with that of a dam failure (Pattengail Dam in 1927). Our data showed greater geomorphic response at Pattengail compared to Mystic. Very few flood stage indicators were observed at Mystic and indicated muted hydrogeomorphic and ecologic responses. In contrast, the size of the flood following the Pattengail dam breach initiated a series of channel adjustments and reworked over 0.2 km 2 of floodplain immediately downstream of the dam. Floodplain vegetation responded similarly. Nearly 100 vegetation points below Mystic Lake Dam showed no statistically significant changes in canopy type in the 20 years since dam removal. However, 165 vegetation points downstream of Pattengail dam indicated active floodplain succession during the first 70 years. Our results suggest that 1) hydrogeomorphic and ecologic responses to dam removal depends on the sizes and timing of high flow events during and following removal. 2) Dam removal effects on channel evolution and floodplain development depend on reach types and their responsiveness to flow regime change. We developed these ideas into testable hypotheses as the basis of a multiyear, interdisciplinary research proposal. Further investigation into the long-term hydrogeomorphic and ecologic response to dam removal/failure will advance the knowledge of dam removal methods and their effects, leading to healthier ecosystems and associated human communities.
Revegetation Study of Adobe Dam, Phoenix, Arizona. Task 4. Revision. Site Characteristics
ABSTRACT
Effects of artificially imposed shade on a Sonoran Desert ecosystem: microclimate & vegetation
Journal of Arid Environments
Solar energy conversion: An analysis of impacts on desert ecosystems
ABSTRACT
Workshop on Ecological Impacts of Solar Energy Conversion
ABSTRACT
Flood Flows and Dynamics of Sonoran Riparian Forests
In the Hassayampa River system, recruitment of Fremont cottonwood Populus fremontii and Goodding ... more In the Hassayampa River system, recruitment of Fremont cottonwood Populus fremontii and Goodding willow Salix gooddingii, depends on 1) large prior-year floods to remove herbaceous cover; 2) high spring flows or rains to stimulate germination on floodplains above the zone of frequent flood inundation; and 3) reduced post-germination flooding to reduce seedling mortality. Small differences in timing of spring floods influence relative recruitment success of the two species because of differences in emergence phenologies. Recruitment of velvet mesquite Prosopis velutina depends on large (>5-yr) floods to disperse seeds to establishment sites on floodplains 1-2 m above the water table, and small (>2-yr) late-summer floods or rains to inundate germination sites. -from Authors
The old growth forest on Mt. Graham (Pinaleno Mountains) of eastern Arizona is comprised of fores... more The old growth forest on Mt. Graham (Pinaleno Mountains) of eastern Arizona is comprised of forest patches rather than being homogeneous in composition. These patches reflect the heterogeneity of disturbances that occur on the mountain. The two primary disturbances have been fire and wind, although clearing for road construction and recently for an astronomical observatory also are important. The forest patches represent different stages in forest succession following disturbance. Patches can be described as open, forest edge, and mature and old growth forest. With these categories, composition and demography of dominant tree species varies and creates smaller patches within the general categories. Variability results from the relative success of pioneer species and the consequent invasion of other species. There appear to be four recovery patterns following disturbance within the Engelmann spruce-corkbark fir (Picea engelmannii-Abies lasiocarpa var. arizonica) forest. These include...
Sustainability of urban and supporting natural ecosystems: Assessing the role of ecological wisdom
Sustainability of urban socioecosystems is dependent on natural ecosystems for goods and services... more Sustainability of urban socioecosystems is dependent on natural ecosystems for goods and services, one being water that often comes from highly modified riverine systems. Management of urban and natural ecosystems and their interactions requires acquired knowledge, ecological wisdom and adaptive management. Modified riverine ecosystems supplying water to urban ecosystems may be sustainable if resistant to alterations and resilient following restoration efforts. Possible sustainability of riverine ecosystems supplying goods and services for urban ecosystem sustainability is addressed. Case studies from semi-arid North America address this relationship. These are adaptive management examples of riverine restoration of (1) Colorado River that supplies water to Los Angeles, CA and Phoenix, AZ; (2) Lower Owens River in eastern California that supplies water to Los Angeles; and (3) Salt River that supplies water to Phoenix. These rivers have been greatly modified to improve water supply c...
Persons seeking admission, employment, or access to programs of the University of Wyoming shall b... more Persons seeking admission, employment, or access to programs of the University of Wyoming shall be considered without regard to race, color, religion, sex, national origin, disability, age, political belief, veteran status, sexual orientation, and marital or familial status. Persons with disabilities who require alternative means for communication or program information (Braille, large print, audiotape, etc.) should contact their local UW CES office. To file a complaint, write to the UW Employment Practices/ Affirmative Action Office,
Fire temperatures and physical characteristics of a controlled burn in the upper Sonoran desert
Journal of Range Management, 1984
... Character-istics of a Controlled Burn in the Upper Son-oran Desert DUNCAN T. PATTEN AND GEORG... more ... Character-istics of a Controlled Burn in the Upper Son-oran Desert DUNCAN T. PATTEN AND GEORGE H. CAVE ... Rangeland in the Upper Sonoran Desert is rela-tively lush because of a bimodal rainfall pattern and burns fre-quently when enough fuel is present. ...
Journal of Contemporary Water Research & Education, 2009
Wetlands, 2010
Research focused on improving our understanding of riparian habitat distribution is becoming incr... more Research focused on improving our understanding of riparian habitat distribution is becoming increasingly important for assessing nutrient buffering potential within developing mountain watersheds. We used field-based vegetation data and digitally-derived terrain variables to (1) assess the usefulness of digital terrain variables for modeling the cross-valley extent of riparian vegetation, (2) compare the strength of hillslope versus fluvial terrain predictors for vegetation prediction, (3) determine a threshold elevation above the channel to be used for coarse delineation of the riparian zone, and (4) implement predictive vegetation models spatially across a 212 km 2 watershed. Elevation above the channel, topographic wetness index and site gradient were the strongest vegetation predictors. In a single-predictor model, the extent of riparian vegetation was estimated at 1.2 m and 2.5 m elevation above the stream for 2nd and 3rd order streams, respectively. Predictors of vegetation composition shifted from fluvial/lateral to primarily lateral with decreasing stream size. Recognizing that optimum grid size depends on landscape complexity and the study variable of interest, our study suggests an optimum grid size of 20-30 m for calculating the topographic wetness index for identification of the transition from riparian to upland vegetation within low-gradient valley bottom areas in this mountain watershed.
Dynamics of the Spruce-Fir Forests on the Pinaleno Mountains, Graham Co., Arizona
The Southwestern Naturalist, 1991
... Mt. Graham red squirrel (Tam-iasciurus hudsonicus grahamensis). Spruce ... sities. Deciduous ... more ... Mt. Graham red squirrel (Tam-iasciurus hudsonicus grahamensis). Spruce ... sities. Deciduous trees included Populus tremu-loides Michx., Quercus gambelii Nutt., Acer gla-brum Torr., and Salix scouleriana Barratt ex Hook. Herbaceous ...
Regulated Rivers: Research & Management, 1996
Dendro-ecological studies indicated that radial growth of Populus trichocnrpa was significantly r... more Dendro-ecological studies indicated that radial growth of Populus trichocnrpa was significantly related to annual streamflow at 20 riparian sites in the eastern Sierra Nevada of California. The strength of the relationship varied among sites, depending on geomorphology and tree cover. The strongest correlation between streamflow and tree growth occurred at sites in wide, unconfined valleys, where alluvial groundwater typically fluctuates directly with surface water. In such areas, trees on streambanks and in the floodplain showed equally strong relationships between flow and growth. In narrow mountain canyons, relationships between tree growth and streamflow were weaker and showed more withinsite variability. Streambank trees in the canyon settings generally showed stronger relationships with streamflow than did floodplain trees. These data suggest that P. tricliocarp trees in confined canyons, in comparison with those in wide alluvial valleys, may rely to a greater extent on water sources that are not in direct hydraulic connection with surface water. Flow-growth models were also stronger at sites where tree basal area and density were low, including sites where flow diversion has caused tree mortality. Sparse tree cover may allow for a greater expression of flow-growth relationships by minimizing the effects of competition for light and other resources, and allowing for greater control of growth by abiotic rather than biotic factors.
Mountain Research and Development, 1996
Landscape and Urban Planning, 1994
This paper reports the results of an assessment of the Verde River Corridor Project (VRCP), the f... more This paper reports the results of an assessment of the Verde River Corridor Project (VRCP), the first citizen-based multi-objective river corridor project to be completed in Arizona. Several studies have identified the Verde River as having national significance and as being in need of protection to conserve its resources. The assessment seeks to test the usefulness of the VRCP as a positive model for river conservation in the southwest United States. Key issues and concerns identified by the VRCP steering committee fell into five general topics: economics and commercial uses, land conservation, private property, recreation, and water. Recommendations for each issue were developed by five subcommittees and incorporated into a plan of action. Progress made by the VRCP in implementing recommended actions was investigated. Specific recommendations for land and water conservation goals were evaluated in order to judge their effectiveness at accomplishing the desired objectives. This evaluation used criteria developed by the US Environmental Protection Agency for developing and implementing effective riparian protection policies. Implications for river corridor planning are examined and strategies used during the VRCP are addressed in terms of transferability to other Arizona sites. 0 1994 Elsevier Science B.V. All rights reserved 0169-2046/94/$07.00 SSDI0169-2046(93)00145-F C..-h.rr~/lefa/ /LandsmprundL'rhan Plann~ng28(/YY4)161-liH E. Aventt er al. /Landscape und C'rban Piamng 28 (1994) 161-l 78
Carbon Dioxide Exchange Patterns of Cacti from Different Environments
Ecology, 1969
ABSTRACT
The increasing responses to symposia devoted to riparian resources in the past decade have create... more The increasing responses to symposia devoted to riparian resources in the past decade have created a need to channel this enthusiasm into a permanent organization. The Arizona Riparian Council was formally organized in October 1986 to provide an annual forum for local coordination of management and research activities. In addition, the Council draws support from individuals representing management agencies, conservation groups, research institutions, and user groups. The importance of forming such local or regional groups is facilitating better communication on the local level, which may lead to greater advocacy of protecting riparian resources on a national level based on grass-roots support.
Rush Creek, which feeds Mono Lake, has been diverted below Grant Lake, totally or in part, for ov... more Rush Creek, which feeds Mono Lake, has been diverted below Grant Lake, totally or in part, for over 40 years. In the early 1980 ' s, because of above normal snow packs, runoff was released into the creek. Minimum flow releases have also been established. The riparian vegetation has responded to these releases. In a few areas, riparian trees and shrubs (e.g., black cottonwood and willow) survived the diversion period but with high stem mortality. These plants are resprouting in response to the 1980's floods. In other areas, new plants are establishing within the floodplain; however, on areas away from the floodplain most riparian plants died and are not regenerating. The patterns of riparian regeneration and environmental requirements of each riparian species have been preliminarily determined.
The restorative potential of dam removal on ecosystem function depends on the reversibility of th... more The restorative potential of dam removal on ecosystem function depends on the reversibility of the hydrogeomorphic effects of a dam and its operations. While dam removal is an established engineering practice, the long-term ecological response remains speculative. We used paleoflood hydrology, topographic surveys, hydrologic modeling (HEC-RAS), and aerial photograph interpretation to investigate the long-term hydrogeomorphic and ecologic responses to dam failure and removal. We compared downstream hydroecological responses of a controlled dam removal, which used natural sediment removal (Mystic Lake Dam in 1985), with that of a dam failure (Pattengail Dam in 1927). Our data showed greater geomorphic response at Pattengail compared to Mystic. Very few flood stage indicators were observed at Mystic and indicated muted hydrogeomorphic and ecologic responses. In contrast, the size of the flood following the Pattengail dam breach initiated a series of channel adjustments and reworked over 0.2 km 2 of floodplain immediately downstream of the dam. Floodplain vegetation responded similarly. Nearly 100 vegetation points below Mystic Lake Dam showed no statistically significant changes in canopy type in the 20 years since dam removal. However, 165 vegetation points downstream of Pattengail dam indicated active floodplain succession during the first 70 years. Our results suggest that 1) hydrogeomorphic and ecologic responses to dam removal depends on the sizes and timing of high flow events during and following removal. 2) Dam removal effects on channel evolution and floodplain development depend on reach types and their responsiveness to flow regime change. We developed these ideas into testable hypotheses as the basis of a multiyear, interdisciplinary research proposal. Further investigation into the long-term hydrogeomorphic and ecologic response to dam removal/failure will advance the knowledge of dam removal methods and their effects, leading to healthier ecosystems and associated human communities.
Revegetation Study of Adobe Dam, Phoenix, Arizona. Task 4. Revision. Site Characteristics
ABSTRACT
Effects of artificially imposed shade on a Sonoran Desert ecosystem: microclimate & vegetation
Journal of Arid Environments
Solar energy conversion: An analysis of impacts on desert ecosystems
ABSTRACT
Workshop on Ecological Impacts of Solar Energy Conversion
ABSTRACT
Flood Flows and Dynamics of Sonoran Riparian Forests
In the Hassayampa River system, recruitment of Fremont cottonwood Populus fremontii and Goodding ... more In the Hassayampa River system, recruitment of Fremont cottonwood Populus fremontii and Goodding willow Salix gooddingii, depends on 1) large prior-year floods to remove herbaceous cover; 2) high spring flows or rains to stimulate germination on floodplains above the zone of frequent flood inundation; and 3) reduced post-germination flooding to reduce seedling mortality. Small differences in timing of spring floods influence relative recruitment success of the two species because of differences in emergence phenologies. Recruitment of velvet mesquite Prosopis velutina depends on large (>5-yr) floods to disperse seeds to establishment sites on floodplains 1-2 m above the water table, and small (>2-yr) late-summer floods or rains to inundate germination sites. -from Authors
The old growth forest on Mt. Graham (Pinaleno Mountains) of eastern Arizona is comprised of fores... more The old growth forest on Mt. Graham (Pinaleno Mountains) of eastern Arizona is comprised of forest patches rather than being homogeneous in composition. These patches reflect the heterogeneity of disturbances that occur on the mountain. The two primary disturbances have been fire and wind, although clearing for road construction and recently for an astronomical observatory also are important. The forest patches represent different stages in forest succession following disturbance. Patches can be described as open, forest edge, and mature and old growth forest. With these categories, composition and demography of dominant tree species varies and creates smaller patches within the general categories. Variability results from the relative success of pioneer species and the consequent invasion of other species. There appear to be four recovery patterns following disturbance within the Engelmann spruce-corkbark fir (Picea engelmannii-Abies lasiocarpa var. arizonica) forest. These include...
Sustainability of urban and supporting natural ecosystems: Assessing the role of ecological wisdom
Sustainability of urban socioecosystems is dependent on natural ecosystems for goods and services... more Sustainability of urban socioecosystems is dependent on natural ecosystems for goods and services, one being water that often comes from highly modified riverine systems. Management of urban and natural ecosystems and their interactions requires acquired knowledge, ecological wisdom and adaptive management. Modified riverine ecosystems supplying water to urban ecosystems may be sustainable if resistant to alterations and resilient following restoration efforts. Possible sustainability of riverine ecosystems supplying goods and services for urban ecosystem sustainability is addressed. Case studies from semi-arid North America address this relationship. These are adaptive management examples of riverine restoration of (1) Colorado River that supplies water to Los Angeles, CA and Phoenix, AZ; (2) Lower Owens River in eastern California that supplies water to Los Angeles; and (3) Salt River that supplies water to Phoenix. These rivers have been greatly modified to improve water supply c...
Persons seeking admission, employment, or access to programs of the University of Wyoming shall b... more Persons seeking admission, employment, or access to programs of the University of Wyoming shall be considered without regard to race, color, religion, sex, national origin, disability, age, political belief, veteran status, sexual orientation, and marital or familial status. Persons with disabilities who require alternative means for communication or program information (Braille, large print, audiotape, etc.) should contact their local UW CES office. To file a complaint, write to the UW Employment Practices/ Affirmative Action Office,
Fire temperatures and physical characteristics of a controlled burn in the upper Sonoran desert
Journal of Range Management, 1984
... Character-istics of a Controlled Burn in the Upper Son-oran Desert DUNCAN T. PATTEN AND GEORG... more ... Character-istics of a Controlled Burn in the Upper Son-oran Desert DUNCAN T. PATTEN AND GEORGE H. CAVE ... Rangeland in the Upper Sonoran Desert is rela-tively lush because of a bimodal rainfall pattern and burns fre-quently when enough fuel is present. ...
Journal of Contemporary Water Research & Education, 2009
Wetlands, 2010
Research focused on improving our understanding of riparian habitat distribution is becoming incr... more Research focused on improving our understanding of riparian habitat distribution is becoming increasingly important for assessing nutrient buffering potential within developing mountain watersheds. We used field-based vegetation data and digitally-derived terrain variables to (1) assess the usefulness of digital terrain variables for modeling the cross-valley extent of riparian vegetation, (2) compare the strength of hillslope versus fluvial terrain predictors for vegetation prediction, (3) determine a threshold elevation above the channel to be used for coarse delineation of the riparian zone, and (4) implement predictive vegetation models spatially across a 212 km 2 watershed. Elevation above the channel, topographic wetness index and site gradient were the strongest vegetation predictors. In a single-predictor model, the extent of riparian vegetation was estimated at 1.2 m and 2.5 m elevation above the stream for 2nd and 3rd order streams, respectively. Predictors of vegetation composition shifted from fluvial/lateral to primarily lateral with decreasing stream size. Recognizing that optimum grid size depends on landscape complexity and the study variable of interest, our study suggests an optimum grid size of 20-30 m for calculating the topographic wetness index for identification of the transition from riparian to upland vegetation within low-gradient valley bottom areas in this mountain watershed.
Dynamics of the Spruce-Fir Forests on the Pinaleno Mountains, Graham Co., Arizona
The Southwestern Naturalist, 1991
... Mt. Graham red squirrel (Tam-iasciurus hudsonicus grahamensis). Spruce ... sities. Deciduous ... more ... Mt. Graham red squirrel (Tam-iasciurus hudsonicus grahamensis). Spruce ... sities. Deciduous trees included Populus tremu-loides Michx., Quercus gambelii Nutt., Acer gla-brum Torr., and Salix scouleriana Barratt ex Hook. Herbaceous ...
Regulated Rivers: Research & Management, 1996
Dendro-ecological studies indicated that radial growth of Populus trichocnrpa was significantly r... more Dendro-ecological studies indicated that radial growth of Populus trichocnrpa was significantly related to annual streamflow at 20 riparian sites in the eastern Sierra Nevada of California. The strength of the relationship varied among sites, depending on geomorphology and tree cover. The strongest correlation between streamflow and tree growth occurred at sites in wide, unconfined valleys, where alluvial groundwater typically fluctuates directly with surface water. In such areas, trees on streambanks and in the floodplain showed equally strong relationships between flow and growth. In narrow mountain canyons, relationships between tree growth and streamflow were weaker and showed more withinsite variability. Streambank trees in the canyon settings generally showed stronger relationships with streamflow than did floodplain trees. These data suggest that P. tricliocarp trees in confined canyons, in comparison with those in wide alluvial valleys, may rely to a greater extent on water sources that are not in direct hydraulic connection with surface water. Flow-growth models were also stronger at sites where tree basal area and density were low, including sites where flow diversion has caused tree mortality. Sparse tree cover may allow for a greater expression of flow-growth relationships by minimizing the effects of competition for light and other resources, and allowing for greater control of growth by abiotic rather than biotic factors.
Mountain Research and Development, 1996
Landscape and Urban Planning, 1994
This paper reports the results of an assessment of the Verde River Corridor Project (VRCP), the f... more This paper reports the results of an assessment of the Verde River Corridor Project (VRCP), the first citizen-based multi-objective river corridor project to be completed in Arizona. Several studies have identified the Verde River as having national significance and as being in need of protection to conserve its resources. The assessment seeks to test the usefulness of the VRCP as a positive model for river conservation in the southwest United States. Key issues and concerns identified by the VRCP steering committee fell into five general topics: economics and commercial uses, land conservation, private property, recreation, and water. Recommendations for each issue were developed by five subcommittees and incorporated into a plan of action. Progress made by the VRCP in implementing recommended actions was investigated. Specific recommendations for land and water conservation goals were evaluated in order to judge their effectiveness at accomplishing the desired objectives. This evaluation used criteria developed by the US Environmental Protection Agency for developing and implementing effective riparian protection policies. Implications for river corridor planning are examined and strategies used during the VRCP are addressed in terms of transferability to other Arizona sites. 0 1994 Elsevier Science B.V. All rights reserved 0169-2046/94/$07.00 SSDI0169-2046(93)00145-F C..-h.rr~/lefa/ /LandsmprundL'rhan Plann~ng28(/YY4)161-liH E. Aventt er al. /Landscape und C'rban Piamng 28 (1994) 161-l 78
Carbon Dioxide Exchange Patterns of Cacti from Different Environments
Ecology, 1969
ABSTRACT