Lower Arroyo Seco: Visit 1


California Naturalist Outing

Lower Arroyo Seco Park
Pasadena, CA
8:45 a.m. to 11 a.m.

Visit 2 | Visit 3 | Visit 4 | Visit 5 | Visit 6

  • From the Rose Bowl Parking Lot (south side) near the aquatic center.
  • Route: Footpath along the road to the trail head
  • Weather: Cold – low 53 F, clear sky.

Visit to the Upper Arroyo Seco

Down the trail into the wild area interface.

Riparian into Oak Scrub through microclimates out to meadow and sage scrub.

Riparian area intersected into man made river channel. Restored habitat with gravel and sandy floor. Willow and Sycamore trees and several smaller plants: papyrus and other nonnative weeds. Wood sorrels were starting to pop out from the dead plant life along the banks. Lots of trash was washed into the plant debris. Amongst the debris were the tell-tale signs of the pandemic—masks of all sorts and colors mixed in with the organic matter.

Lower Arroyo Park, looking north, where the concrete channel meets the riparian creek bed.
Lower Arroyo Park, looking north, where the concrete channel meets the riparian creek bed.

Moving from the Riparian space to the oak forest, I moved about 50 yards from the first stop down the trail. Here, the soil was much more humus rich and less rocky. There was much more biomass on the floor. Here, the landscape was populated with Toyon, oaks and sycamore trees. The canyon space seemed to narrow and felt cooler that the air above.

Read: Becoming A Naturalist

From here, I moved with the group further south, traveling under the 134 freeway (a very large bridge in the space). There were many signs of new and old human development, from the road and freeway spans to old concrete chunks embedded in the soil substrates. We traveled around the dam and through restored habitat “meadow.” The meadow is a mixed field of native and invasive plants watered by an occasional release from the concrete dam with water from the riparian areas. This space was not quite meadow, not quite riparian instead being a mix of the two.

Lower Arroyo park under the 134 freeway looking south west.
Lower Arroyo park under the 134 freeway looking south west.

Continuing south, we entered the oak forest and sage scrub chaparral open space. Here we identified a growth of poison oak and a pack rat mound.

At this point, we ended the outing and returned to the vehicles in the parking lot.

Lower Arroyo Seco Park looking north towards the Colorado Street bridge.
Lower Arroyo Seco Park looking north towards the Colorado Street bridge.

Most notable on the trip was hearing coyotes howl after an emergency vehicle passed nearby. It really illustrated how close the wild is to the not wild space.


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