BY ARIELLE ZIONTS FOR NOGALES INTERNATIONAL
Extract: A pristine portion of Sonoita Creek that was discovered last fall is providing local environmentalists with inspiration as they work to restore eroded sections of the stream.
From where the creek intersects with the northeast side of Patagonia Lake to a small waterfall a little more than a half-mile upstream, the waterway is fast moving and highly eroded. But members of the organization Friends of Sonoita Creek (FOSC) and Peter Stacey, a professor at the University of New Mexico specializing in streams in the southwest, discovered that above the waterfall – technically referred to as a “head cut,” meaning an abrupt vertical drop caused by erosion – the water slowly meanders through multiple branches level with the ground.
Stacey explained in a phone conversation that in his 20 years of field work across the southwest he’s only seen a handful of streams – including this portion of Sonoita Creek – “functioning the way it used to ... before humans had an impact on it.”
“It’s extremely rare,” he said. “It’s an example of what all of us are shooting for when we do restoration work.”
On Tuesday morning, the Patagonia-based FOSC led a group of people to observe the differences above and below the head cut. The excursion also included a demonstration of stream monitoring techniques and discussion of efforts to preserve the pristine section of the creek, reverse existing erosion and prevent further damage to ensure that the stream continues as a source of groundwater.
Kathy West, a 61-year-old retiree from Patagonia, described the lower portion of the creek as a “muddy mess.” Above the head cut, she said, “It was a little bit wilder up here and the stream was wider and it was very, very scenic.”
“It’s what it should be,” West said, noting that she could see bugs and flowers growing near the upper portion of the stream. (...)
Food chain restoration for pollinators: Regional habitat recovery strategies involving protected areas of the Southwest
Authors: Steve Buckley, National Park Service and Gary Paul Nabhan, University of Arizona Southwest Center
Abstract: The steep declines over the last quarter century of wild pollinators in the Southwest among native bees, monarch butterflies, hummingbirds, and nectar-feeding bats have come during a time of accelerated climate change, are likely due to a variety of stresses interacting with climatic shifts. Nevertheless, there is mounting evidence that the declining availability and altered timing of floral resources along “nectar corridors” accessible to pollinators involves climatic shifts as a serious stressor that had been previously underestimated. Longitudinal studies from both urban heat islands and rural habitats in Southwestern North America suggest that the peak flowering of many wildflowers serving as floral resources for pollinators is occurring 3 to 5 weeks earlier in the spring than a century ago, leaving “phenological gaps” in nectar resource availability for certain pollinators. To avoid the threat of what Dobson and others have termed “food web collapse”, we have initiated ecological restoration efforts in semi-arid zones that attempt to a) assemble more resilient plant-pollinator food chains and b) hydrologically restore watercourses to ensure that water scarcity will be less likely to disrupt re-assembled food chains in the face of droughts, catastrophic floods and other correlates of global climate change. We recommend “bottom-up food chain restoration” strategies for restoring nectar corridors in protected areas on or near geopolitical and land management boundaries in all regions, but particularly in the “Southwest” or U.S./Mexico desert border states. We highlight the binational and multi-cultural workshops we have facilitated to communicate about and initiate restoration of mutualistic relationships among plants, pollinators, and people to protected area managers on both sides of the border.
Read the comprehensive study
"A Restoration Economy Seeks to Take Root in the Borderlands" - an interview of BR executive director David Seibert for The Weekly Green on KXCI Community Radio
Listen to the Weekly Green's interview of Borderlands Restoration's Executive Director, David Seibert to learn more about the innovative work of Borderlands Restoration and its partnering organizations including the Borderlands Restoration Leadership Institute.
"When paired with detention structures that stabilize wet or dry systems, native plants effectively knit the landscape together and root our work in place. " - David Seibert
An animation project by Chloe Fandel about water harvesting in stream channels.
How has the landscape in the dry grasslands of Arizona changed over time? How have humans affected the stream channels?
In this region, most groundwater is recharged through the sediment at the bottom of stream channels. So how might changes in the channel affect the rates of infiltration (floodwater at the surface soaking into the ground) and recharge (the infiltrated water traveling down to the water table and being stored)?
This video is based on background research for Chloe Fandel's MS Thesis:
"The Effect of Gabion Construction on Infiltration in Ephemeral Streams". The full thesis can be accessed here: http://search.proquest.com/openview/9...
Low-tech rock structures called gabions are commonly used in dryland stream channels to reduce erosion, slow floodwaters, and increase infiltration. Gabions may also increase water availability for riparian vegetation, and increase the duration of surface flow in ephemeral stream channels. However, their effects on infiltration and recharge are not well-understood. This study tested low-cost methods for easily quantifying the total infiltration induced by gabion construction in an ephemeral stream channel, over the course of a single flow event. We used well-established methods to find point infiltration fluxes from subsurface temperature time-series. Unique to this study, we then upscaled these measurements to the gabion’s entire area of influence using time-lapse photo data, which recorded the onset of flow and the duration of ponding. For a flow lasting ~5 hours, we ran 225 model scenarios, estimating that a single gabion could have increased the total infiltrated volume in the channel reach between it and the next gabion by as much as 255% or as little as 0%, but the most likely scenario is a 10.8% increase. We found the photo data to be invaluable in obtaining these estimates, and in understanding the dynamics of a remote field site. Future work would benefit from more precise measurements of point infiltration fluxes and better records of ponded surface area over time. If these improvements are made and our estimates can be replicated reliably, they would suggest that gabions are a more powerful restoration and management tool than previously understood.
More information at the USGS Aridland Water Harvesting Study:
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