Pacific Air Influences on the Biodiversity of Baja California

BAJA WORKING GROUP – CLIMATE SCIENCE ALLIANCE

Pacific Air Influences on the Biodiversity of Baja California Sula Elizabeth Vanderplank (Pronatura Noroeste) Exequiel Ezcurra (University of California, Riverside) Tony Burgess (Botanical Research Institute of Texas) In memory of Tony Burgess, who passed before this piece could be published.

Coastal fog sustains Cedros Island Pine forest and multiple rosettophilous succulents.

PHOTO CREDIT: SULA VANDERPLANK

Key Takeaways •

Cool, moist air from the Pacific Coast influences species distributions, and to a large extent controls the overarching distribution of plant species on the Baja California Peninsula.

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Fog deserts and coastal fog refugia are just two examples of habitats dependent on Pacific air and coastal low clouds and fog.

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Fog, low clouds, and cool moist air significantly impact the phenology, ecology, fecundity, recruitment, and behavior of plant and animal species.

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Distance from the coast and landform are particularly important considerations for biodiversity conservation.

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What is the focus and area of your research?

Our research focuses on the distribution of rare and endemic species on the Baja California Peninsula.

As part of this research, we are particularly interested in how fog and other Pacific air influences control plant distributions and, in turn, affect species up the trophic chain. We have studied the impacts of fog on plant diversity and phenology in the mediterranean-desert ecotone in Baja California and have been amazed by the significant impacts that the presence of coastal low clouds and fog (CLCF) has on these ecosystems. These impacts include but are not restricted to: changes in phenology (synchrony and duration), biodiversity, productivity, demography, fecundity, biogeography, ecology, trophic interactions, and, in other ecosystems, restoration potential and recovery.

We are now working to promote the protection of coastal lands, and to better understand the impact of fog in the central deserts and on the overall biogeography of the Peninsula.

How do you see climate change impacting the focus of your work?

Climate change only increases the importance of the fog refugia in Baja California. As our climate changes, these buffered climates not only protect species that are being pushed to the edge of their climate envelope, but also provide a climate that can promote and support speciation and radiation of new species. For this reason, both ancient lineages (paleoendemics) and new lineages (neoendemics) thrive in foggy lands. As much as research in the subject is urgent and important, awareness of the importance of fog to future conservation efforts is now the leading concern.

It is unknown how fog presence will change in future, will the fog change height, duration, timing? One thing we can be sure of is that any fog will be better than no fog, and these foggy coasts will be important regardless of any shift in patterns of presence.

What climate impacts are you seeing in your region?

The presence of fog can ameliorate the impacts of other climate change stressors (e.g., solar radiation and temperature, risk of wildfire,

shortened

growing

seasons,

drought)

(1).

Analyzing

fog presence to better understand how to address some of these other climate challenges would be extremely valuable.

An analysis of fog reach would also benefit decision-making on priorities for land conservation on the Peninsula.

Fog dependent epiphytes (ball moss) on the thick-stemmed water storing boojum tree.

PHOTO CREDIT: SULA VANDERPLANK

Baja California is already suffering a serious overdraw of fossil water and freshwater aquifers, leading to saltwater intrusion in coastal plains, particularly in agricultural regions (2, 3). The importance of protecting the coastal lands (up to around 15 km from the coast, depending on topography) cannot be overstated when considering the fight against extinction.

What are you most concerned about?

Baja California’s native species and wildlands lose ground to urban development and agriculture every day. Without targeted protections, coastal lands where rare and endemic species can survive will soon be completely obliterated. The majority of narrowly endemic plant species in the state of Baja California are found in the coastal plain between Ensenada and San Quintin (4).

We are still unaware of any studies that look at the importance of fog in the central deserts, yet we suspect a cold Pacific air influence that extends all the way down to Bahía Magdalena. The footprint of these fogs can be seen in the maps of distribution of more mesic plant families and genera such as Rosaceae, and in the presence of coastal lichens (5) such as Niebla, named for its affinity for fog (niebla = fog in Spanish).

What are the gaps in understanding that need more research?

The following are broad categories of research where further investigation is urgently needed, adapted from the San Diego County Climate Report (6): •

Correlating local Coastal Low Clouds and Fog (CLCF) data to existing biological data, especially using long-term datasets.

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Further applied research linking management implications to the presence and extent of CLCF.

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Gathering data on species’ responses to low clouds and fog.

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The design of new studies that address CLCF impacts on the biology of Baja California.

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Citizen science crowdsourced data, such as querying iNaturalist by foggy days versus non-foggy days.

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Ecosystem services, including heat mitigation for human populations.

Satellite image of fog from the marine layer, associated with the cold California current on the Pacific Coast of the Baja California peninsula.

CREDIT: NASA

What is your plan moving forward to start to better understand or minimize the impacts from climate change?

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Raise awareness of the importance of fog and foggy areas for conservation and restoration. This needs to be done at every level—with the government, the non-profit community, land managers, stakeholders, and teachers. General outreach to citizen scientists can also help gather data (e.g., promote efforts such as NASA’s Students’ Cloud Observations online; take a photo of a cloud—the website allows you to post a georeferenced photo of a cloud and see the satellite animation and a map of the location).

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Seek collaborators and funding for additional research and conservation efforts.

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Bergerocactus emoryi combs moisture from the coastal air with its mass of thin spines.

Emphasize and support efforts to protect foggy coastal lands.

CREDIT: SULA VANDERPLANK

References 1. Vanderplank, S. E., & Ezcurra, E. (2016). Marine influence controls plant phenological dynamics in Mediterranean Mexico. Journal of Plant Ecology, 9(4), 410–420. https://doi.org/10.1093/jpe/rtv066 2. Aguirre-Muñoz, A., Buddemeier, R. W., Camacho-Ibar, V., Carriquiry, J. D., Ibarra-Obando, S. E., Massey, B. W., Smith, S. V., & Wulff, F. (2001). Sustainability of Coastal Resource Use in San Quintin, Mexico. AMBIO: A Journal of the Human Environment, 30(3), 142–149. https://doi.org/10.1579/0044-7447-30.3.142 3. Vanderplank, S., Ezcurra, E., Delgadillo, J., Felger, R., & McDade, L. A. (2014). Conservation challenges in a threatened hotspot: Agriculture and plant biodiversity losses in Baja California, Mexico. Biodiversity and Conservation, 23(9), 2173–2182. https://doi.org/10.1007/s10531-014-0711-9 4. Riemann, H., & Ezcurra, E. (2005). Plant endemism and natural protected areas in the peninsula of Baja California, Mexico. Biological Conservation, 122(1), 141–150. https://doi.org/10.1016/j.biocon.2004.07.008 5. Rundel, P. W., Bowler, P. A., & Mulroy, T. W. (1972). A Fog-Induced Lichen Community in Northwestern Baja California, with Two New Species of Desmazieria.

The Bryologist, 75(4), 501–508. JSTOR. https://doi.org/10.2307/3241205 6. Jennings, M. K., Cayan, D., Kalansky, J., Pairis, A. D., Lawson, D. M., Syphard, A. D., Abeysekera, U., Clemesha, R. E. S., Gershunov, A., Guirguis, K., Randall, J. M., Vanderplank, S. E., & Stein, E. D. (2018). San Diego County ecosystems: Ecological impacts of climate change on a biodiversity hotspot (No. CCCA4-EXT-2018–010; California’s Fourth Climate Change Assessment, p. 178).

California Energy Commission.

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