The First Annual Report of the Borderlands Habitat Restoration Initiative
The borderlands of southeastern Arizona and northwestern Mexico are a globally important, yet highly threatened, biodiversity “hotspot.” Riparian areas and wetlands in this arid region play a disproportionate role in sustaining biological diversity, yet it is estimated that over 90% of the historical wetlands and riparian areas have been lost due to habitat destruction and changing land uses. Native wetlands, or cienegas, once a common feature of the region, are now so reduced in extant that they are considered the most endangered natural ecosystem in Arizona. Upland woodlands and grasslands are recovering from past overgrazing but now face an even bigger threat from habitat fragmentation and loss.
The Cuenca Los Ojos Foundation (CLO) works to restore the biodiversity of the borderland region between the United States and Mexico through land protection, habitat restoration, and wildlife reintroduction. In the fall of 2010, Cuenca Los Ojos and the Biophilia Foundation signed a Memo of Understanding to work together to restore biodiversity in the borderlands region. Specifically, the new partnership agreed to first document the impact of the 30 years of restoration work conducted by CLO founders Josiah and Valer Austin, and then to use the lessons learned to restore habitat throughout the borderlands region. This report documents the progress made in the first year of this partnership.
Restored riparian habitat at Cajon Bonito. Cuenca Los Ojos means “watershed of springs.” In November of 2010, CLO, the Biophilia Foundation, and the Hummingbird Monitoring Network sponsored a habitat restoration workshop in Patagonia, Arizona. The workshop brought together scientists and conservationists and focused on hummingbirds and hummingbird plants. Hummingbirds are highly threatened by loss of habitat and southern Arizona has more hummingbirds than any other area in the United States. Hummingbirds are also an excellent model system for engaging scientists, conservationists, and local citizens in community-based habitat restoration projects. The general principals and approach to habitat restoration that emerged from the workshop led directly to a new cooperative initiative to restore habitat throughout the borderlands region.
The Borderlands Habitat Restoration Initiative is a collaborative conservation movement seeking to restore ecological resiliency to a 4,000 square mile area along both sides of the U.S.- Mexico border. Our goals are
- To empower local citizens to restore ecosystem services in their own communities, and
- To have a measurable impact on regional wildlife populations and ecosystem services, with an initial emphasis on pollinators and pollination services
We view restoration as a multi-step process that begins with restoring physical processes (principally stream flow and groundwater recharge) and then restoring vegetation and food chains that support biological diversity. The essential final step is reconnecting humans and their ecosystems by engaging local citizens in the restoration of local ecosystem services.
“We believe that habitat restoration is not sustainable unless local citizens understand the benefits received from the restorations and actively participate in restoring ecosystems and ecosystem services in their own communities. Most people already understand the value of water and, with some prompting, they readily understand the services provided by pollinators. We are piloting our community engagement program in Patagonia, AZ, in the Sonoita Creek watershed in southeastern Arizona. The November 2010 meeting, where regional experts on plants and pollinators met for two days with local conservationists, was followed in the Spring of 2011 with two community meetings to explain our goals and approach to restoration. Encouraged by the response, we organized a series of workshops and “potting luck” parties involving participants in propagating native hummingbird plants. Participants received free plants for their home gardens and, in turn, agreed to provide cuttings for future potting parties. We also participated in local festivals and established a website.
A specific goal for this year has been to engage 100 local citizens in the propagation of 2000 hummingbird plants, and we are on target to meet that goal. To date, we have established two local pollinator gardens (one at a high school and one at Patton house, a well-known hummingbird viewing venue) and are working to establish a third on the town square in Patagonia. We currently have on hand about 1,400 additional hummingbird, bee, and butterfly plants, most of which will be given to participants or used on experimental plots on the local Nature Conservancy preserve. We will engage citizens in planting the experimental gardens and we will train participants to monitor the survival of the transplants, their flower and fruit production, and the visitation rates of bees, butterflies, and hummingbirds.
Scientific Research Documenting Impacts of Restoration. We believe that it is important to document that restoration activities actually work and, in particular, that there are measurable improvements in habitat quality and wildlife populations. To that end, we have initiated a vigorous research program to monitor the effectiveness of our restoration work and to guide future restoration activities. A few of the highlights of the restoration work are listed below, followed by a more detailed account of the various projects. In 2011, we accomplished the following:
- Conducted a remote sensing analysis to quantify restoration effects on vegetation
- Developed a Geographic Information Systems to support the restoration activities
- Hosted nine student interns from Mexican universities who assisted on various projects
- Conducted a resurvey of vegetation on 20 transects at Rancho San Bernardino that had originally been surveyed just prior to the beginning of active restoration
- Conducted wide-spread surveys of both hummingbird nesting sites and fruit and nectar producing plants that are utilized by hummingbirds
- Repeated riparian drainage profile and vegetation assessments
- Collected new baseline data on drainage profiles and vegetation
- Initiated a sedimentation study to better quantify effect of hydrologic restoration
- Examined the response of grassland birds to grassland restoration efforts
- Established multiple camera traps to better evaluate presence of wildlife species.
Remote Sensing Analysis: Landsat data was analyzed in the month of June from 1984 to 2011. This analysis was designed to quantify restoration effects on riparian vegetation, and the increase in the acreage of the San Bernardino Cienega. The results for the analysis confirm an increase of 1920 acres of riparian area in the San Bernardino Ranch boundary and an increase in the size of the cienega from 52 acres to 84 acres post-restoration.
Student Research and Internships: Three student interns, one from Puebla and two from Mexico City, worked in support of the hummingbird project. Each intern plans to study hummingbird biology as part of their research in graduate school. An additional six students from the University of Sonora spent six weeks working with scientists and CLO staff.
The summer began with the resurvey of vegetation plots established in 2000. After the second week, University of Sonora students were asked to design research projects that could be completed during their internship. Students continued to work daily with the following scientists in conjunction with their research: Bob Minckley (Plant surveys), Cindy Tolle (resurvey of the San Bernardino drainage/gully profiles and vegetation-de la Torre research from 2000), wet-dry surveys of Rio San Bernardino, Hay Hollow and Silver Creek; Chuck Minckley (monitoring native fish populations); Keith Shallcross (camera monitoring). Ron Pulliam (Sparrow surveys); Susan Wethington (Hummingbird Monitoring), Kate Boersma (aquatic insect survey). The summer activities culminated with a BBQ and a hands-on gabion construction workshop led by Valer Austin. Four of our summer interns have had papers accepted to the third Madrean Archipelago Conference in 2012. In addition to hummingbird and other research support by student interns, five student research projects were completed in 2011. They are:
- Mammal diversity on Rancho San Bernardino Bonillas Monge Mario Erandi and Valdez Coronel Carlos Manuel. Erandi and Carlos trapped mammals for a one week period at three sites. One site was adjacent to a pond, a second site was in Silver Creek (newly restored), and a third site was within the San Bernardino Cienega. Traps of varying sizes were used in all locations. The greatest number and diversity of mammals was found at the pond site, most likely due to food resources and vegetation cover. The results support the need for a more complete mammal survey in the restored and unrestored areas of San Bernardino but do indicate there is greater biodiversity of mammals and numbers in restored areas. The students also recorded tracks and scat and suggested camera trapping for information gathering on species distribution.
- Habitat use of the Checkered garter snake (thamnophis marcianus) in Silver Creek Jesús Ramón Valenzuela Rosas. Jesus Examined population differences of the Checkered garter snake in three types of wet areas (1) deep tanks, ponds with a depth greater than 30 cm, (2) narrow drainages heavily vegetated with a water depth less than 30 cm, (3) wide drainages with little vegetation and a water depth less than 30cm. Jesus found garter snakes preferred the narrow, heavily vegetated drainages. The dense vegetation and shallow regions allowed for better feeding for the snakes.
- Stratigraphy correlation on alluvial deposits of two terraces on Silver Creek Monica Olguin-Villa. Monica selected two locations along Silver Creek to analyze the deposition stratification of the river. One location was in a dry location with little vegetation and the second location was a wet region that was dense with riparian vegetation. Her studies indicated that the older deposits along Silver Creek corresponded to fast floodwaters. Newer deposits showed a slower flow resulting in more Cienega-like depositions.
- Effect of food resource distribution on composition and structure of a hummingbird community on Rancho San Bernardino Melinda Cardenas Garcia. Melinda monitored hummingbirds in two locations for a period of five days using artificial feeders. One location was in the center of the San Bernardino Cienega and the second was adjacent to the cienega in the Hay Hollow drainage (restored). Two species of hummingbirds were recorded, the black-chinned and the broad-billed. Hummingbirds were found in both locations though the restored drainage location was visited much more during the period of the study which suggests better foraging and protection.
- Bird of Rancho San Bernardino, Melinda Cardenas Garcia and Monica Olguin-Villa. Melinda and Monica selected five sites for their bird studies at San Bernardino (1) by the main house (2) Silver Creek (newest restoration) (3) Rio San Bernardino (older restoration) (4) Ponds southeast of the main house and (5) the Cienega. Birds were observed for seven days in the morning (6 -10 am) and evening (5-7 pm). During the observation period, 48 species of birds were observed.
Gully Profiles and Riparian Vegetation Analysis: In the summer of 2001 (pre-restoration) Noelia de la Torre analyzed six sites along the San Bernardino Arroyo in Sonora Mexico. In her analysis, de la Torre measured the following features: 1) plant species composition and cover, 2) vertical structure of the vegetation, 3) the size distribution of individuals of the main arboreal species, and 4) topography of the drainage channel and basic features of surface water flow. This is an area that has seen extensive restoration since 2001. This field season we located the 2001 transects and repeated her work. David Delgado, a botany student from the University of Sonora is still analyzing data collected this field season. However, it is clear that both the profiles and the vegetation at all six locations have changed dramatically over the past decade.
Wet-Dry Survey San Bernardino Ranch: During the summer of 2011 students worked with Cindy Tolle to map the three primary riparian drainages on the San Bernardino Ranch; Hay Hollow, Silver Creek and the Rio San Bernardino. The data was collected prior to the monsoon season in the driest period of the year, in order to confirm the presence or absence of water. The main channel of the streams were walked and mapped with a GPS in track mode. Physical GPS locations were marked along the arroyos at each direction change and any point of interest (gabion), road intersection, pollinator plant location etc., in order to overlay this dataset with others in the GIS. Areas that were dry, wet and damp were noted. Four continuous kilometers of wet stream was mapped in the San Bernardino system. There were many other smaller areas of water within the riparian systems, particularly in Hay Hollow and the Rio San Bernardino. Through old photos, and correspondence with individuals who visited this ranch prior to 1999, we are documenting a dramatic increase in perennial waters and riparian vegetation in response to restoration activities. Most remarkable, this increase has taken place during a long-term regional drought that has persisted longer than restoration activities.
Green-line and Photo-Point Surveys: In the fall of 2010 photo point locations upstream and downstream of gabions in Silver Creek, Hay Hollow and San Bernardino were selected and surveyed for green-line vegetation analysis according to the procedure outlined in the La Jornada Experimental Range Guide: Monitoring Manual for Grassland, Shrubland and Savanna Ecosystems. Silver Creek and the acquisition of baseline monitoring data was the priority during the monitoring design process, though data was also collected on the other two primary drainages. Over time, these photo points will enable us to detect visual change while the greenline transects allow us to analyze changes in the vegetation at each transect location.
Sedimentation studies: In mid-September nine hydrological monitoring stations were placed along riparian drainages on San Bernardino Ranch to monitor surface water discharge, and 1-2 subsurface observation locations to monitor soil moisture at depths up to three meters. These were placed to catch late monsoon runoff events to fully test the system before the winter rainy season. This will allow us to measure any late monsoon storm runoff as well as test the system to ensure a full season of data collection during the 2012 monsoon season. We installed subsurface moisture sensors adjacent to some drainage. These will indicate water availability for plants in the cienega, and will allow us to understand how the channel restoration efforts effect lateral moisture movements into adjacent landscape.
By measuring stream flow into the San Bernardino Ranch cienega, at critical locations along riparian drainages on the ranch, and below all tributary junctions at the highway bridge, we can quantify the fate of surface water at San Bernardino cienega and evaluate the effects of restoration efforts. We will be able to evaluate how well restoration efforts lead to enhanced surface water availability, beneficial sediment deposition along arroyo channels, and to evaluate progress towards the eventual goal of restoring surface water and vegetation to the former cienega surface.
Hummingbirds: The work done by Cuenca Los Ojos in the San Bernardino River watershed has restored miles of riparian vegetation, the primary nesting habitat for the common hummingbird species in this region and the habitat that supports the most diverse biological species assemblages in arid lands. Restoration of physical processes such as stream flow and groundwater recharge is a critical first step to ecosystem restoration in arid regions. The next critical step is to restore the vegetative communities and food chains that support these assemblages. Hummingbirds, as pollinators, provide the ecosystem service needed for many plants to produce viable seeds and fruit which then become food resources for many animal species. And as pollinators, they rely almost exclusively on floral nectar for their energy resources.
Hummingbird ecology, physiology, and movement patterns are closely related to the distribution, phenology, and abundance of their nectar plants and any change in nectar availability will directly influence their distributions and abundance. Thus, it is critical to also monitor nectar availability and plant phenology in concert with hummingbird populations. An additional challenge for this restoration effort is the lack of standardized monitoring protocols for evaluating the effectiveness of these efforts. Thus in addition to gathering the initial data on hummingbirds and their nectar plants, we are developing and testing the needed standardized protocols that will effectively assess change in hummingbird diversity and abundance as well as availability and phenology of their nectar plants.
Study sites were chosen along a restoration/disturbance gradient within the two watersheds that are the initial focus for the Borderlands Habitat Restoration Initiative. Two sites occur in Sonora on CLO ranches, San Bernardino and Los Ojos. CLO Restoration efforts are most recent at the San Bernardino ranch, which is the ranch where most nectar plants will be planted and where the riparian vegetation is most recently restored. The third study site is along Sonoita Creek where it enters Patagonia Lake. It is similar in elevation to San Bernardino Ranch and likely supports the same hummingbird community that will develop as restoration efforts continue at the San Bernardino.
Restoration efforts at Rancho San Bernardino have created habitats that are now used by hummingbirds. The proposed restoration of hummingbird-pollinated plant species is needed for the ranch to fully support hummingbird populations. Both Black-chinned and Broad-billed hummingbirds attempted to nest at San Bernardino but by mid-July, no active nests were found and few hummingbirds were detected. The use of San Bernardino by nesting hummingbirds appears to be relatively recent as few old nests were found compared with Los Ojos, which would suggest that recent restoration activities are having a positive effect.
Grassland Sparrows: Mechanical removal of shrubs and extensive reseeding with native grasses has resulted in restoring open grasslands but we know little of the impacts of such treatments on animal populations native to the region. Because of their wide geographic distribution, sensitivity to habitat change, and high species diversity, sparrows were chosen as an indicator group to access the impact of the grassland restorations on animal populations. Population densities are being compared between treatment and control areas at San Bernardino and population estimates at San Bernardino will be compared to results from previously published surveys conducted using the same survey methods in grazed and ungrazed grasslands in southern Arizona and northern Sonora. The results of 48 surveys to date indicate substantial differences between treated and control sites. Only two sparrow species (Blackthroated and Cassin’s) appear to be breeding on the shrub-dominated control sites compared to 4-5 breeding species (Black throated, Cassin’s Sparrow, Botteri’s Sparrow, Lark Sparrow, and possibly Rufous-winged Sparrow) on the treatment sites.
Differences in the winter months are even greater between control and treated sites. Only Black-throated Sparrows were recorded on the control sites in winter compared to a total of 12 species (Black throated, Savannah, Brewer’s, Vesper’s, Grasshopper, Cassin’s, White-crowned, Lark, Rufous-winged, Lark Bunting, Canyon Towhee, Green-tailed Towhee) were recorded on the treatment sites during fall and winter surveys. Preliminary statistical analysis also suggests far higher densities (~ 3 to 5 times greater) in both winter and summer on the treatment sites compared to the control sites.
The pattern established for sparrows (more individuals and species on treated sites) is also true for other taxonomic groups of birds. Among the more notable species recorded on treatment but not control sites are the following: Bell’s Vireo, Blue Grosbeak, Lazuli Bunting, Loggerhead Shrike, and Crissal Thrasher. Gambel’s Quail and Verdin appear to be more common on the control sites.
Vegetation resurveys: Rancho San Bernardino was purchased by CLO in 1999. During the summer of 2000 vegetation plots were established on Rancho San Bernardino, and the adjacent San Bernardino National Wildlife Refuge in Arizona USA. Originally, these plots were to serve as permanent sites for tracking succession of pollinators and flowers. Plots were located in each of the following habitats; cienega or desert marshland, riparian, mesquite forest, desert scrub, grassland, and abandoned agricultural field.
New funding acquired for the summer of 2011 was used to relocate the plots and transects, measure vegetation along these transects, and take repeat photographs of images taken originally in 2000. We are currently compiling all data from transects and cover from both 2000 and 2011 for analysis. The goal for the transect vegetation data is to ask if there are quantitative changes in the vegetation between 2000 and 2011. The repeat photographs will augment the transect data to be used to investigate if qualitative vegetation changes have occurred that are not evident in the data from transects.
At this point, we have remarked all sites and transects on Rancho San Bernardino with t-posts and aluminum tags so that future changes in the vegetation can be monitored. Comparison photographs generally show few differences in the vegetation of plots in desert scrub, grassland, and mesquite forest. Photographs of agricultural areas did show that there has been a rapid proliferation of the invasive reed, Arundo donax, in one field. Lastly, one cienega site shows strong evidence of increasing water levels; many of the mesquite trees at this site are either dead or have numerous dead branches unlike trees nearby in higher areas.
Camera Trapping: In 2011 we expanded our camera trapping project to three additional CLO ranches. Though the focus of this project is mammals, we do record information on secondary species that these cameras document. We now have hundreds of wildlife photos and videos taken by these cameras including black bear, coati, javelina, mountain lion, bobcat, deer, badger, and three species of skunks. Mexican gray wolves were released in the Sierra San Luis, near to where six CLO ranches are located and we hope to begin capturing images and video of these in the near future. Perhaps, the most exciting discovery from this project has been the discovery of ocelots on CLO properties.