Geology topics

Research about San Carlos Apache Reservation, Upper Gila River watershed

Source-linked reports with geographic coverage including San Carlos Apache Reservation, Upper Gila River watershed.

2 recordsLinked to original sources

USGS2024

Mapping riparian vegetation response to climate change on the San Carlos Apache Reservation and Upper Gila River watershed to inform restoration priorities: 1935 to Present

The riparian vegetation within the San Carlos Apache Reservation (hereafter Reservation), within the Upper Gila River watershed extending from southwestern New Mexico into southeastern Arizona, provides immense ecological and cultural value to the people of the San Carlos Apache Tribe (hereafter referred to as the Tribe/Tribal) but has experienced substantial changes and stresses over the past century because of fluctuations in climate and a series of human-induced and natural disturbances. This research addresses these challenges by analyzing the riparian vegetation within the Upper Gila River watershed using aerial and satellite imagery, and by documenting the direct relationship to fluctuations in climate conditions. Results from this study would be provided to the Tribe to help the Tribe develop a restoration plan for their riparian forests. We show that the riparian vegetation has largely increased overall in greenness throughout the study period (i.e., 1985 through 2021), despite periods of drought conditions. This extends to the end of our study period particularly with native vegetation in the upper watershed. However, non-native and invasive tamarisk vegetation within much of the lower watershed has shown declining trends and increasing vegetative stress. Furthermore, these areas have experienced a large increase in wildfire presence and other disturbances. Nevertheless, Tribal restoration applications have been shown to increase native vegetation plant cover, suggesting that restoration activities have been successful overall.

Arizona, New Mexico↗

USGS2023

Riparian vegetation response amid variable climate conditions across the Upper Gila River watershed: Informing Tribal restoration priorities

Riparian systems across the Southwest United States are extremely valuable for the human and ecological communities that engage with them. However, they have experienced substantial changes and stresses over the past century, including non-native vegetation expansion, vegetation die-offs, and increased fire activity. Vegetation management approaches, such as ecological restoration, may address some of these stressors as well as reduce the risk of future impacts. We apply remote sensing to inform restoration priorities along the upper Gila River within the San Carlos Apache Reservation and Upper Gila River watershed. First, we develop a spatially and temporally explicit trend analysis across three observed climate periods (1985–1993, 1993–2014, 2014–2021) using the Landsat-derived indices to quantify changes in riparian vegetation conditions. These maps can be used to identify areas potentially more at risk for degradation. Second, we analyze changes in riparian vegetation within a climate framework to better understand trends and the potential effect of climate change. Vegetation greenness has largely increased throughout the watershed despite intensifying drought conditions across our study period, though areas within the lower watershed have shown increased stress and higher rates of wildfire and other disturbances over the past 5-years. Nevertheless, small-scale restoration activities appear to show improving vegetation conditions, suggesting efficacy of these restoration activities. Results from this study may be integrated with restoration objectives to develop a restoration plan that will help riparian vegetation communities adapt to change.

Arizona↗