Importance/Issues

Sonoran Desert Network parks contain reaches of some of the major rivers in the American Southwest: the Gila, Santa Cruz, and Verde. These streams and rivers (hereafter streams), and the riparian systems they support, dominate the natural and cultural features of the parks where they occur. However, the condition of rivers within each park unit is greatly influenced by drivers and stressors occurring over broad watersheds and upstream segments located well beyond park boundaries. Monitoring the ecological and hydrologic condition of these rivers from multiple perspectives in an integrated fashion is key to understanding and managing these critical habitats.

Parks Monitored

Gila Cliff Dwellings NM, Montezuma Castle NM, Tumacácori NHP, Tuzigoot NM

Monitoring Objectives

Determine the status of and detect trends in stream channel morphology parameters (over 5-year intervals and following major flooding events).

Determine the status of and detect trends in common (>25% absolute plant cover) perennial native and non-native plant species and all perennial plant lifeforms within Park riparian stream corridors (over 5-year intervals and following major flooding events).

Determine the monthly status of and detect interannual trends in total stream discharge.

Determine the quarterly status of and detect interannual trends in core water quality parameters, alkalinity, primary nutrients, and biological condition.

Determine the annual status of and detect interannual trends in selected pollutant metals, and benthic macroinvertebrate communities.

Potential Measures

Channel morphology: Channel width x depth ratio; cross-sectional area, sinuosity, channel slope, and sediment composition.

Riparian plant communities: Plant alliance type and distribution; community similarity measures over time and space.

Riparian plant species and lifeforms: % vegetative cover for common (>25% absolute cover) perennial plants and perennial plant lifeforms; % frequency of uncommon (<25% absolute cover) perennial plants and annual plant lifeforms.

Benthic macroinvertebrates: Relative abundance by family and/or functional group; integrated biological index (IBI); Observed Expected metrics.

Stream discharge: Stream flow in cubic feet per second (cfs) and acre feet per year (afy).

Core water quality parameters: Water temperature (degrees C), dissolved oxygen (mg/L water), instantaneous flow (cfs), specific conductance (microSiemens per cm degrees C), pH (su), turbidity (NTU).

Alkalinity: CaCO3 (mg/L water)

Primary nutrients: Concentrations of total N and total P (mg/L).

Biological condition: Biochemical oxygen demand (BOD) in mg/L; E. coli in most probable number of colony-forming units /100ml(MPN/100ml).

Pollutant metals: Concentrations of each of 13 pollutant metals (mg/L).

Management Applications

Perennial streams are important focal resources for the parks where they occur. Managers can use monitoring information to guide park management actions and address proximate issues that are occurring within park boundaries. Stream monitoring information also provides an index of overall watershed condition, providing park managers with information to effectively address broad-scale issues with adjacent land owners and other land management and regulatory agencies. Finally, stream conditions provide insights into broader landscape conditions due to the critical ecological services these systems support over surrounding terrestrial landscapes - services that are greatly disproportionate to the relatively meager area of these riparian corridors.

Protocol Development Status

This protocol has been in development and testing since FY2006, and most aspects have been implemented. Testing for fish and riparian vegetation monitoring will occur in FY2009, and we expect to complete the draft protocol by the end of calendar year 2009.

Status & Trends

Status information is currently being analyzed and interpreted for 2007-2008; there is insufficient temporal information for trend determination at this time.

Project Leads

Evan Gwilliam, Ecologist (Aquatic)