Climate change: Swann song for saguaros?



Climate change is a global pressing issue that will continue to affect our environment and local ecosystems; including our National Parks. With varied and extreme weather patterns becoming more frequent, we will see more apparent effects on our National Parks.

Saguaro National Park is one that Pima Community College students are familiar with and often frequent. Saguaro National Park can also be used to help perceive the effects of our ever changing climate.

Don Swann, a rangeland manager for Saguaro National Park, sat down and talked on climate, saguaros and Pima students’ roles in helping preserve our national wonders.

Q: How has Saguaro National Park changed how it presents information about the changing climate?

One of the things we are interested in from a national park point of view is protecting saguaros and the desert plants that this park was established to protect it for future generation.

We study the saguaros here and have been for the past 75 years and some cases we go back to the same saguaros to see how they’re doing, as well as looking new saguaros entering the population and how we are doing.

One of the things we have seen in the last 20 years or so in the desert as its had a pretty deep drought is we are seeing fewer young saguros that we were for example in the 1980s. Smaller saguaros can’t really store water really well so they rely on cooler temperatures and wetter soil to survive the first few years of like. We just haven’t had as many saguros surviving in the last couple of decades.

Q: Does that have anything to do with invasive species like buffel grass?

One of the issues we have is invasive plants like buffel grass, we’ve been combating in various ways. buffelgrass competes with saguaros. Precious rainfall that comes during the summer, the grass will often suck it before the saguros get a chance to use it.

The additional problem we have is just the higher temperatures we have been experiencing in the last 20 years. It seems to be drying out the soils more rapidly than it has in the past, and saguros just don’t seem to be surviving.

Q: How has the park changed its policies to help prevent fires?

We are just becoming a lot more conscious about fire. Fires have gotten bigger around the West, we’ve seen some big fires in the park in the last few decades. We’ve included more restrictions than we’ve had in the past in recognition of this danger.

One of the concerns we have down in the desert here is that desert don’t historically burn frequently, maybe not all in some areas because there is so much space in between the plants, on top of the buffelgrass that fills in that space.

Buffelgrass has adapted for where, where it can carry fire and come right back where as a saguros in that area will die. We are really concerned with the changing fire regime due to these invasive grasses.

Q: Have you had to be more vigilant when it comes to park visitors bringing in potential fire hazards?

The thing about managing a national park is that we’re all in this together. We really need the visitors to help us in any way they can,” Swann said “this includes things like being careful with fire, keeping an eye out for fire, making sure you’re being fire conscious.

We haven’t had too many human-started fires in the park in the last few years and we hope it will continue that way.

Q: Tucson has historically had flowing rivers and aquifers that keep the ecosystem hydrated, have the aquifers be lowering or rising due to recent rains?

Desert water hydrology is a really complex topic and I’m not a hydrologist, but I have heard the aquifer that was falling for quite a while in the central part city has actually come up in the past few years.

We aren’t as reliant on groundwater as we have been in the past because we are getting some water from the Colorado river from the Central Arizona Project Canal.

In fact the per capita water use in Tucson has started to decline in the last few years. It’s great evidence that people are paying attention to the environment, are being careful with what they use, recognize they live and the desert and that water is a precious resource that we need for not only our survival but for the plants and animals that live here.

Q: We are seeing record levels of rainfall, record high temperatures, how has the park adjusted to these rapid fluctuations.

I can’t predict the future and certainly can’t predict the future weather. We have had some pretty big floods in 2006, and these high temperatures even effects when we can go out and do research in the park.

The main thing is we need to use science to understand the changes that are occurring here to the plant and animal community, and think about what actions we can take today to protect these plants and animals for the future.

Part of it is working collaboratively with scientists from colleges to really understand what’s going on.

Q: Talking about changing behavior and what we can do to protect these parks, what are some easy students that Pima students can take to help protect the parks they love?

One of the things I really believe in is that the best thing you can do for a national park is bring your friends out to hike. The more we can create an awareness of how great this place is, create experiences that are awesome that you can share with others.

It has a sort of generational effect, we want people to love this park, we want people to use this park.

The more people that use and care about it, then we can get people to talk about ‘What can I do to protect this place.

There a lot of small things we can do to protect this place, things like not littering, using less water, but also the idea of leaving no trace and really respecting the plants and animals that are here, listening to them, and enjoying it here.