Dale Turner - Academia.edu (original) (raw)

Papers by Dale Turner

Uma notata in the Mohawk Dunes had population densities in good habitat of 15- 17 lizards/ha. Tes... more Uma notata in the Mohawk Dunes had population densities in good habitat of 15- 17 lizards/ha. Testis volumes peaked in April-May and declined to low levels by August. Egg production peaked in May during 1995 but did not occur in spring 1996. Minimum convex polygon home range estimates were 530 (±70 SE) m2 for 2 adult males and 228 (±82) m2 for 8 adult females. Adjusted for sample size bias, these estimates were 994 (±422) and 774 (±302) m2, respectively. Subadults had smaller home ranges. Uma notata actively used perennial plants as escape cover, preferentially selecting Ambrosia dumosa. I found significant use of plant materials in Uma notata diet with both ontogenetic and seasonal shifts in proportions of plant items. Their diet included 65 taxa of arthropods from 39 families, along with 13 plant species in 7 families. I also studied survival rates, tail loss, substrate selection, and thermal effects.

Sonoita Creek State Natural Area of southern Arizona lies in the "sky island" archipela... more Sonoita Creek State Natural Area of southern Arizona lies in the "sky island" archipelago of southwestern North America, which is known for its rich biodiversity. Mountain ranges in the region contain unique biotic assemblages, with distributional edges, gaps, and outliers that lead to a variety of fascinating biogeographic questions (Warshall 1995). The valleys provide corridors between montane populations and allow extensions of distribution for lower-elevation species. Lowlands are generally the best-watered, most productive parts of the landscape, and have also been the most heavily affected by human use, both globally and locally. The Sonoita Creek valley has been haphazardly visited by herpetologists for decades, but most collecting has been done along the main road, Highway 82, due to constraints of access to private property. This inventory was a volunteer effort. The goals were to provide qualitative information about the herpetofauna of Sonoita Creek State Natura...

Natural resources journal

The Cienega de Santa Clara, is undergoing alterations due to operation of the Yuma Desalting Plan... more The Cienega de Santa Clara, is undergoing alterations due to operation of the Yuma Desalting Plant in the USA. This is the largest remaining wetland in the delta region, containing rare and endangered species including desert pupfish Cyprinodon macularius and Yuma clapper rail Rallus longirostris yumanensis, yet no official consideration has been given to the effect of the altered conditions on the wetland flora and fauna. -from Authors

As persistent wetlands in arid regions, ciénegas represent important resources for the maintenanc... more As persistent wetlands in arid regions, ciénegas represent important resources for the maintenance and preservation of regional biodiversity. The history of ciénegas in the American Southwest over the last 8,000 years provides information on the dynamics of growth, longevity, and stability of these habitats under previous climate conditions. Proxy data such as sedimentology, pollen, charcoal, and isotopes preserved in ciénega sediments provide information on the formation, disturbance, resilience and state changes within these systems. This long-term perspective is compared to the recent history of degradation observed in the region. Once formed, ciénega surfaces alternate between wetland and dryland phases, identified by changes in pollen preservation and isotopic signatures. These phase changes are hypothesized to be controlled by groundwater-table depths. The degraded state of many extant ciénegas may be similar to the dryland phase, but may also require active management to init...

Aquatic Conservation: Marine and Freshwater Ecosystems, 2007

Page 1. Turner and List: Arizona native fish streams 1 This is a preprint of an article published... more Page 1. Turner and List: Arizona native fish streams 1 This is a preprint of an article published in Aquatic Conservation: Marine and Freshwater Ecosystems, Vol. 17: 737-748 (2007). http://www.interscience.wiley.com Habitat ...

Southwest Naturalist, 2003

... AMPHIBIANS AND REPTILES OF THE WHETSTONE MOUNTAINS, ARIZONA. Dale S. Turner a e g , Peter A. ... more ... AMPHIBIANS AND REPTILES OF THE WHETSTONE MOUNTAINS, ARIZONA. Dale S. Turner a e g , Peter A. Holm b , Elizabeth B. Wirt c f , and Cecil R. Schwalbe d. ... Methods. Study Area The Whetstone Mountains lie approximately 11 km southwest of Benson, Arizona (Fig. ...

Due to water limitation, thresholds in hydrologic and biogeochemical processes are common in arid... more Due to water limitation, thresholds in hydrologic and biogeochemical processes are common in arid and semi-arid systems. Some of these thresholds such as those focused on rainfall runoff relationships have been well studied. However to gain a full picture of the role that thresholds play in driving the hydrology and biogeochemistry of xeric systems a full view of the entire array of processes at work is needed. Here a walk through the landscape of xeric systems will be conducted illustrating the powerful role of hydrologic thresholds on xeric system biogeochemistry. To understand xeric hydro-biogeochemistry two key ideas need to be focused on. First, it is important to start from a framework of reaction and transport. Second an understanding of the temporal and spatial components of thresholds that have a large impact on hydrologic and biogeochemical fluxes needs to be offered. In the uplands themselves episodic rewetting and drying of soils permits accelerated biogeochemical proces...

The Verde River above Horseshoe Reservoir in central Arizona is unregulated and retains perennial... more The Verde River above Horseshoe Reservoir in central Arizona is unregulated and retains perennial flow. In an arid land, theVerde River is a rare green corridor that is enjoyed by humans while supporting abundant plants and wildlife. Although surface water diversions for irrigation have operated in the Verde Valley since the late 1800s, and groundwater pumping occurs throughout the watershed, a natural flow regime predominates and substantial aquatic and riparian diversity remain. However, the ecological integrity of the Verde River could be threatened by the water demands of a rapidly expanding population. Thus far, scientific studies have focused on groundwater conditions while the relationships and water needs of the riverine ecosystem have gone largely unstudied. Developing scientific understanding of the functional relationships between stream flow, aquifers, and the biological system is essential to managing this rare southwestern river ecosystem. Ecologically sustainable wate...

One-hundred twenty-two species of seed plants, representing 95 genera and 35 families are documen... more One-hundred twenty-two species of seed plants, representing 95 genera and 35 families are documented for the 7,700 ha Mohawk Dune Field and its immediate surroundings, located in Yuma County, Arizona, USA. Three major habitats were studied: dunes, adjacent sand flats, and playa. The dunes (including interdune swales) support 78 species, of which 13 do not occur on the adjacent non-dune habitats. The adjacent non-dune habitats (sand flats and playa) support 109 species, of which 43 were not found on the dunes. The total flora has 81 annual species, or 66% of the flora. The dune flora has 63 annual (ephemeral) species, or 81% of the flora—one of the highest percentages of annuals among any regional flora. Of these dune annuals, 53 species (84%) develop during the cool season. No plant taxon is endemic to the Mohawk region. There are 8 dune, or sand adapted, endemics— Cryptantha ganderi, Dimorphocarpa pinnatifida, Dicoria canescens, Ditaxis serrata, Pleuraphis rigida, Psorothamnus emor...

The Southwestern Naturalist, 2003

Open-File Report, 2014

ABSTRACT The Arizona ecoregion map was compiled at a scale of 1:250,000. It revises and subdivide... more ABSTRACT The Arizona ecoregion map was compiled at a scale of 1:250,000. It revises and subdivides an earlier national ecoregion map that was originally compiled at a smaller scale. The approach used to compile this map is based on the premise that ecological regions can be identified through the analysis of the spatial patterns and the composition of biotic and abiotic phenomena that affect or reflect differences in ecosystem quality and integrity.

The Southwestern Naturalist, 2010