5. PROCESO DE EGRESO EN LA FUNDACIÓN SEMILLAS DE ESPERANZA: UNA
5.3 PERCEPCIONES PROFESIONALES ACERCA DEL EGRESO DEL TRABAJO
Of the three species, Adenostoma fasciculatum is most resilient to increasing
temperatures, followed by Arctostaphylos virgata and then Arctostaphylos canescens. Marin Manzanita gains resilience through its geographical location, while Hoary Manzanita is most at risk in its current range.
By comparing climate change projections to suitability traits, temperature exposure risk can be assessed. The Cal-adapt local climate snapshot tool is helpful for this analysis as the current thresholds can be compared to projected changes in order to determine sensitivity by population. The Cal-adapt climate snapshot tool utilizes both the A2 high-emissions projection and B1 low-emissions projection so that estimates provide a range of best-case and worst-case scenarios in accordance with models. Future results can be estimated by overlaying current population data with projected temperature data. Results through Cal-adapt are region-specific by county or gridded quadrat, so differences in microclimate can at least be partially credited. These overlays provide estimates of how temperature increases from climate change may influence each population.
Adenostoma fasciculatum
Chamise is predicted to benefit from increased temperatures and other projected factors of climate change (Cornwell et al.,2012). The species currently has a large temperature range of about 19°C with July high threshold averaging 36°C and December low averaging -1°C.
Throughout the study area, A. fasciculatum is most widespread in hot, inland areas. For example, a lofty population on Mount Diablo withstands average July high temperatures of 28+°C and remains a dominant shrub on the mountain (C). The species is predicted to thrive and encroach on other less dominant plants.
Marin County:
Low emissions B1: +1.5°C High emissions A2: +2.7°C
By population area: 1.5°C-2.9°C increase
Population area in Marin County includes Mount Tamalpais to Samuel P. Taylor State Park Current species population area July mean and high: 18° and 27.2°
Sonoma County and Napa County are grouped into the same watershed, but will be analyzed separately for the sake of climate projections.
Sonoma County: Low emissions B1: +1.7° C 0 5 10 15 20 25 30 35
Summer low Summer high
Adenostoma fasciculatum -Marin County Projections
and Thresholds
Current B1 A2
Summer High Tolerance
High emissions A2: +2.9°C By population area: 1.7°C-3°C
Current population in Sonoma County is near Sonoma State University ranging west to Lokoya Current species population area July low and high: 19°C high 27°C
Napa County:
Low emissions B1: +1.8°C High emissions A2: +3.2°C By population area: 1.7°C-3°C
Current population in Napa County is approximately from Vichy Springs to Pope Valley Current species population area July mean and high: mean, 18°C high 25°C
0 5 10 15 20 25 30 35 40
summer low summer high
Adenostoma fasciculatum-Sonoma County
Projections and Thresholds
Current B1 A2
Summer High Tolerance
Contra Costa County:
Low emissions B1: +1.7°C High emissions A2: +3.1°C
By population area: 1.7°-3°
Concentrated around Mount Diablo with additional populations from Concord to Antioch Current species population area July low and high 15.4°C, 30°C
Alameda County: Low emissions B1: +1.8°C 0 10 20 30 40
Summer low Summer high
Adenostoma fasciculatum-Napa County
Projections and Thresholds
Current B1 A2 Summer High Tolerance 0 10 20 30 40
Summer low Summer high
Adenostoma fasciculatum-Contra Costa
County Projections and Thresholds
Current B1 A2
Summer High Tolerance Figure 22. Napa County projections.
High emissions A2: +3.2°C By population area: 1.8°-3.2°
Robust populations throughout Oakland Hills and near Contra Costa County border, largest populations of any of the other counties
Current species population area July low and high: 15.4°C, 28°C
Santa Clara County:
Low emissions B1: 1.9°C High emissions A2: 3.2°C By population area: 1.7°-3.2°
Santa Clara County population is approximately west of San Jose as well as near Palo Alto Current species population area July low and high: 12.1°C, 29.3°C
0 5 10 15 20 25 30 35 40
Summer low Summer high
Adenostoma fasciculatum-Alameda County
Projections
and Thresholds
Current B1 A2 Summer High Tolerance
San Mateo County:
Low emissions B1: 1.7°C High emissions A2: 3°C
By population area: 1.7°C-3.2°C
Population dispersed throughout Eastern San Mateo, mostly Butano State Park, Pescadero, and near Redwood City
Current species population area July low and high: 12.1°C, 24.8°C
Arctostaphylos canescens:
Hoary Manzanita lacks the same volume of formal analysis and existing literature as the other two species, but as a species with paleoecological records from cooler, northern climates its response to rising temperatures remains critical (Vasey, personal communication).
Adenostoma fasciculatum -Santa Clara
County Projections and Thresholds
40 Summer High Tolerance 0 10 20 30
Summer low Summer high
Current B1 A2 0 10 20 30 40
Summer low Summer high
Adenostoma fasciculatum-San Mateo
County Projections and Threshold
Current B1 A2
Summer High Tolerance Figure 25. Santa Clara County projections.
Temperature range is approximately 17.7°, December low tolerance -2.2°, July high tolerance 33°
Marin County:
Low emissions B1: +1.5°C High emissions A2: +2.7°C
By population area: 1.5°C-2.9°C increase
Population area in Marin County is primarily on Mount Tamalpais Current species population area July mean and high: 16.11°, 28.3°
Sonoma County:
Low emissions B1: +1.7° C High emissions A2: +2.9°C By population area: 1.7°C-3°C
Main populations near Santa Rosa and Napa County border
Current species population area July low and high:low 10°C high 28°C 0 10 20 30 40
Summer low Summer high
Arctostaphyloscanescens -Marin County
Projections and Thresholds
Current B1 A2
Summer High Tolerance
Napa County:
Low emissions B1: +1.8°C High emissions A2: +3.2°C By population area: 1.7°C-3°C
Current population in Napa County is Northwest and Southeast corners of the county Current species population area July mean low and high: low 11.8°C high 33.6°C
0 10 20 30 40
Summer low Summer high
Arctostaphylos canescens-Sonoma
County projection and threshold
Current B1 A2 Summer High Tolerance 0 10 20 30 40 50
Summer low Summer high
Arctostaphylos canescens
-
Napa County
Projections and Threshold
Current B1 A2
Summer High Tolerance Figure 28. Sonoma County projections.
San Mateo County:
This graph represents a relict population that is no longer located in San Mateo County. Relict population located on King’s Mountain, last recorded in 1902 and dispersed throughout Eastern San Mateo, mostly Butano State Park, Pescadero, and near Redwood City.
Low emissions B1: 1.7°C High emissions A2: 3°C
By Relict population area: 1.7°C-3.2°C Relict Population area Summer low and high: 12.1°C, 24.8°C
This species will be greatly affected by rising temperatures in its current range and reach a summer high threshold in the A2 scenario, which may stress populations and lead to decline. This San Mateo graph is meant to demonstrate that the species could succeed in this county.
Arctostaphylos virgata:
This endemic species is only present in Marin County. Temperature range is the smallest of all three species at approximately 3.3°C, December low tolerance is 5.5°C, July high tolerance is 26.6°C. This species is the most sensitive to extreme high temperatures. As an endemic
species only present in Marin county, this is the only county that will be examined for Arctostaphylos virgata.
Marin County:
Low emissions B1: +1.5°C High emissions A2: +2.7°C
By population area: 1.5°C-2.6°C increase
Population is endemic to Point Reyes and Western Marin County. Current species population area July mean and high: 17.8°, 18.6°
Figure 30. San Mateo County projections.
0 10 20 30
Summer low Summer high
Refugia Potential San Mateo
Current B1 A2
Summer High Tolerance
A. virgata will not reach the summer high threshold, even with the A2 scenario. This analysis reveals that the species range is within an area of refugia, so even though it is a sensitive species, temperatures will not exceed its tolerance threshold. However, it is important to keep in mind that the hottest time of year will likely extend due to climate change and that extreme heat days will be more common, which will stress the species further. (Parmesan, 2003, Hsu 2015). The temperatures for this graph are slightly lower than the other Marin graphs because the species grows in Western Marin closer to the coast, whereas the other two grow in Central Marin and on Mount Tamalpais, exposed to higher temperatures and a higher change in temperature.