On this journey, my goal was to reach and observe the path up to the Gould Mesa Trail camp which is a short jaunt from the parking lot at the JPL Bridge. This trail was surprisingly busy for the mid-weekday with hikers, dog walkers, casual walkers, and young children in a school group.

The trail was a mix of open, natural ecosystems, rock walls (with mixed composition granite), rick falls (some recent) and old structures—some of which were still in regular use as homes. There were several abandoned bridges and the remnants of old cabin homes, many of which still very much intact despite the building long gone from the site. It was amazing to see so many details from the structures including steps leading to nowhere, stone walls with built inviting river rock benches, and foundations set with grid precision. The juxtaposition was stark between the wild reclaiming the crafted.

The wind up in the canyon was strong but not prohibitive to being in the space. It alternatively howled and halted without forward or advance notice. At one point, the wind kicked up some irritant causing me to choke and cough, the cause of which I could never ascertain. Rinsing my mouth and getting out of the area it occurred in (just inside the foundation of an old cabin foundation) it stopped just as quick as it occurred.

This path, if anything else, was a perfect specimen of a “wilderness trail.” It followed a meandering creek, twisting over and through it. Along the way were several old washed-out bridges blocked by with all manner of barriers. Wire fencing, barbed wire, physical barriers, and natural overgrowth—making the prohibited paths all the less inviting. If the old physical barriers weren’t interesting enough, along one bridge, a bowling ball was festooned on post, out of place, but tastefully situated as a clear waypoint to the campsite. For as wild as the space was, it still had plenty of signs of past human use and/or presence.

Unlike previous areas, this path seemed to have less fauna at the path edge. Birds were present, but not in great abundance or even in ear shot except for the occasional cooing of a pigeon. Leaving the path, I did venture down into the creek space to see what life was present, if any. I was delighted to see small fish (trout?) and what I later learned was a California newt. This native was in its aquatic form, swimming at the foot of a larger boulder in the creek bed.

These large boulders were a hallmark of this trip and found every few dozen feet in the trees and along the creek bed up the canyon floor. Many looked to be many years in place with lots of overgrown vegetation surrounding them. Some, like the one in the creek with the newt, seemed to be ideal hovels or dens of one kind or another for animals looking for shelter. None of the shelters made from the large boulders seems human size, but I can imagine both larger and smaller such dwellings exist in places less accessible to the day-tripper naturalist. The degree of rockfall was significant all along the path.

At one point along the path, a colleague and I walked through a meadow, of sorts, surrounded on both sides by riparian trees and shrubs on the creek side and oak and scrub ion the dryer, western, slope side. Remarkably the soil was near entirely dry and sand like form years and years of decomposing granite stone pulverizing into fine grains of sand. What was so remarkable was that it had the quality of beach sand and yet many plants were firmly anchored and growing happily. It was in this location that I found a Yerba Santa in bloom and a high volume of non-native grasses growing profusely between Laurel sumacs, sugar bush, and yucca. One of these sugar bushes was in full and resplendent bloom. It was the only one I found in the space this way—covered in pink, white, and read flowers.

Despite the many people along the trail, I did not see as much poison oak or hemlock. This told me that the path to the campground was less disturbed and filled in with other less advantageous plants. That’s not to say both weren’t just behind the trail, but they weren’t growing in what I would think to be disturbed areas. Why this was the case, I believe, was because the trail edges were relatively undisturbed, meaning few ventured off the trail and into the brush, not giving the toxic plants the opportunity to creep into the disturbed spaces.

Read: Becoming A Naturalist

Reaching the Gould camp, I took a few minutes to take it all in. It stood out to me how disturbed the camp site was with open dirt and few shrubs are the edges. There were several old cabin footings and all the accoutrements of a camp site. I noticed the same squared poured concrete floors, like old cabin footprints down the canyon.

Here, I turned back around and headed down the trail back to the parking lot listening to the wind pick up and roar through the canyons taking in the mix of native and non-native trees left over from times past when the presence of humans tried to shape the land to their personal tastes. I arrived back into civilization near noon and concluded my days trip.

Field Observations

• Lots of rock fall
• Large newt at the base of a rock
• Walkers, mountain bikes and young children in school groups
• Loud wind through the canyons
• Old infrastructure: bridges, cabins, walls
• Bowling ball on a bridge
• Not as much poison oak (non-disturbed spaces)

Observed Species

• Alder – Alnus rhombifolia
• Arroyo Willow – Salix lasiolepis 
• Black Sage – Salvia mellifera
• Buckwheat – Eriogonum fasciculatum
• California Sage – Artemisia californica
• Chilicothe – Marah macrocarpa
• Elderberry – Sambucus melanocarpa
• Laurel Sumac – Malosma laurina
• Mule Fat – Baccharis salicifolia
• Toyon – Heteromeles arbutifolia
• Western Sycamore – Platanus racemosa
• Mugwort – Artemisia douglasiana
• Castor Bean – Ricinus communis
• Tree tobacco – Nicotiana glauca
• Sugar Bush – Rhus ovata
• Wild Cucumber – Marah macrocarpa
• Thick-leaved Yerba Santa – Eriodictyon crassifolium
• Big Berry Manzanita – Arctostaphylos glauca
• Bigleaf Maple – Acer macrophyllum
• California Newt – Taricha torosa
• Pine Trees (several)
• Grasses (various)
• oak(s)

For this trip into the space, our goal was to look at the oak forest up into the El Prieto Trail. This path snaked up the northern side of a steep sloped canyon creating a unique example of patch ecology between riparian creek below, oak forest along the trail line and sage/chaparral high up on the hotter sun exposed slopes. This mix of space created an interesting microclimate or sorts from the presence of water, shade producing tree structures (oaks) the hot dry slopes that took the brunt of the morning and daytime sun.

In this configuration, the two axes of water and temperature made for the perfect boundary zones such that each of the patch communities could thrive and flourish in the space. I would add that the axis is a three-way measurement with the slope contributing to the sun exposure and temperature control.

In much of the mixed communities, the leaf litter combined to make a thick mulch layer—three to four inches deep. Below the detritus, the loamy soil was still damp to the touch, despite having rained a week or more prior. And, like any good opportunists, non-native plants such as castor bean, Asian elm and invasive mustard showed itself in the space. Interestingly, none of these non-natives seemed to overpower the native plants—maybe as only early colonizers, but it seemed they had a much harder time growing in the non-disturbed space. This struck me as a sign of the trail ecology as being healthy and thick while nearby spaces with less water and more exposure, struggled. Trees and shade played a huge factor. In the dappled sunlight on the edges, grasses of all manner of origin grew along with patches of hemlock, coastal wood ferns, scorpion weed, and pacific pea grew side by side poison oak and other riparian ecology.

Throughout, lots of Chillicothe grew through and into shrubs and trees along the trail, along with large healthy toyon and black sage. All of which in its own unique biologic niche occupying and sharing spaces that to a casual passerby would seem impossible to call home. In many cases, to get a plant ID or even a snapshot would require a daring feat of leaning over an edge of the steep slope to grab a branch or flowering stem.

For early April, the space felt alive and happy.

Read: Becoming A Naturalist

Even the wildlife was out in abundance. Hover flies and gnats darted around, a beehive of some composition hummed just off the trail, and hummingbirds, wren, doves, and woodpeckers foraged and went about their daily existence. I was surprised at the number of butterflies and caterpillars about, even so much as to capture a photo of a White-lined Sphinx caterpillar just going about its business.

As unique sightings go, I observed a few interesting mushrooms, some beetles, and birds, just walking through the space. On one long fallen dried log in an open dry space, remnants of what looked to be Turkey Tail like fungus, long dried and sun bleached, clutched onto the length of tree.

At one location, I used the BirdNET app to ID a Bewick’s wren and a Nuttall woodpecker—both doing their bird thing not too far off the narrow path. Many of the birds that chose to not be seen and stayed at considerable distance from any passersby.

On my way back, I stepped down into an open glade to see how a riparian niche over topped by oaks and tall alder and willow. The floor of which was covered, in some places nearly a feet deep, with fallen leaves and detritus. This space had a magical feel as highly filtered sunlight barely made it through the canopy making the whole space look like a post-card. That magic, however, was disturbed by signs of man’s presence from an abandoned tire and basketball, both slowly being swallowed by the falling organic matter.

These human intrusions to the otherwise natural space were just one example of our presence. On the trail, there were several hikers, people on mountain bikes, and objects lost by both. Of the people on bicycles, many occupied the trail going great speeds which seemed to present a significant hazard to both human and fauna. Personally, I had to dodge several with their fast-approaching sheep bells announcing their presence before coming into sight. I suppose this is just a hazard of the trail and something to watch out for like a horseback rider, bear or, rattle snake.

Lastly, I used this excursion to gather some data as it relates to the different plant communities and in one unique plant patch that encompassed riparian, sage, chaparral, and oak forest which yielded interesting results. In just a short space, plant diversity seemed to explode in a mix of variety and location.

After these surveys I returned to my starting point, checked myself back in and departed for the day.   

Field Observations

• Many mountain bikes (in the time of my observations)
• 4 trail hikers
• Bird calls from Berwick’s Wren and a Nutall woodpecker
• Several mushrooms (2 fresh, one set dried)
• Large trash/debris (tire/basketball in creek)
• Poison oak in nearly every cooler/wet space.
• Lots of insect life (diabolical ironclad beetle, gnats, bees, butterflies
• White-lined sphinx caterpillar
• Many lizards along trails
• Old concrete gabion channel walls (creek flow chokes)
• More exotic plants (acacia and Pacific pea)
• Hemlock in great abundance
• Patch habitat following sunlight/slope paths
• Grasses growing in niche biomes
• Thick detritus leaf mulch

Observed Species

• Alder – Alnus rhombifolia
• Arroyo Willow – Salix lasiolepis 
• Ash – Fraxinus genus (non-native)
• Black Sage – Salvia mellifera
• Black Walnut – Juglans californica
• Buckwheat – Eriogonum fasciculatum
• California Sage – Artemisia californica
• caterpillar scorpionweed – Phacelia cicutaria
• Chilicothe – Marah macrocarpa
• Coastal woodfern – Dryopteris arguta
• Common Conecap – Pholiotina rugosa
• Cootmundra wattle – Acacia baileyana
• Desert wishbone-bush – Marabilis laevis
• Diabolical Ironclad Beetle – Phloeodes diabolicus
• Dodder – Cuscuta californica
• Elderberry – Sambucus melanocarpa
• Elm (Chinese elm?)
• Grasses (many)
• Grasses (various)
• Hemlock – Conium maculatum
• Invasive/non native mustards
• Laurel Sumac – Malosma laurina
• Miners lettuce
• Mulch Maids – Leratiomyces percevalii
• Mule Fat – Baccharis salicifolia
• oak(s)
• Pacific pea – Lathyrus vestitus
• Poison Oak – Toxicodendron diversilobum
• streambank Springbeauty – Claytonia parviflora
• Sunflower
• Toyon – Heteromeles arbutifolia
• Weeds (many)
• Western Sycamore – Platanus racemosa
• White-Lined Sphinx – Hyles lineata

This was our first excursion up into the Upper Arroyo as a class. The goal of this outing was to observe the space, look at the similarities and differences of plant communities and to try and see the space as a mosaic of patches, a “landscape ecology.” Part of that process included visually analyzing the percentage of coverage of species and naming “patches” by the three most common species in a patch, starting with the most dominant species and descending to the least. I.E.: Patch name: first species, second species, third species. This becomes clusters of species to create a mosaic.

The location is a geologically interesting one with faults and multi-level ground morphology creating pools and running streams of water coming down from the hill into deep channels of bedrock filled with sand and gravel that snake their way down into the Los Angeles river basin along the Arroyo Seco. At the trail head, the RockD app shows late cretaceous Granitic rocks, leucocratic granodiorite pushing, fracturing, and breaking down into the sand and gravel filling the Devil’s Gate dam.

The space has an interesting history entwined with the space race and the (infamous) rocket scientist Jack Parsons who launched solid rockets in the in the wide shoals of the arroyo. Those tests, and barrels of jet fuel dumped into the, then, mostly empty riverbed creating a modern day federal super fund clean-up site (along with cancer hot spots from polluted ground water). Percolates, a cancer-causing chlorine-oxygen molecule, is a salt and used as an oxidizer for pyrotechnic devices has been found in the deep ground water run-off from the hills and picked up in the, now clean, riverbed.

Much lie the Lower Arroyo, the upper is dynamic and historical site with its own ecological history and anthropogenic impacts from past and present manipulations. When measured in geologic time it is but one small effect in a much longer process (non-the-less toxic to human).

Broadly, as a class we discussed the many natural effects on the region from fires, floods, people, and earthquakes, it very much took on the mantle of a dynamic environment—one that is always changing and moving (growing, burning, shaking and falling).

Read: Becoming A Naturalist

Immediately at the creek, willow, alder, and mule fat populated the edges, crisscrossing the moving water and creating an organic canopy of tree limbs and leaves overhead. Further up, oaks, sycamore, sage and buckwheat dotted the canyon walls with walnut, ceanothus and yerba santa (the latter being edible, the taste reminding me of a dentist’s office).

Taken in total, the Upper Arroyo is very much a wild space but with a wide breadth of human adaptation and use (and re-use) with a significant presence over the last century.

Field Observations

• Lots of kids in outdoor schools.
• Old roads, rock walls, trails, and small buildings.
• Many mountain bike riders
• Dramatic slope effects
• Patchwork plant communities
• A vast number of tumbled stones, from very small to very large

Observed Species

• Buckeye – Aesculus californica
• Poison Oak – Toxicodendron diversilobum
• Black Sage – Salvia mellifera
• California Sagebrush – Artemisia californica
• Laurel Sumac – Malosma laurina
• Elderberry – Sambucus melanocarpa
• Yerba Santa – Eriodictyon crassifolium
• Black Walnut – Juglans californica
• Toyon – Heteromeles arbutifolia
• Arroyo Willow – Salix lasiolepis 
• Alder – Alnus rhombifolia
• Mule fat – Baccharis salicifolia
• California Quail – Callipepla californica
• Grasses (various)

This trip was different than the previous ones as I sought to observe and note examples of local geology, human activity (past and present) and the use of the landscape by past indigenous peoples.

Also of interesting note, I followed the trail on the west side of the creek down to a point past the archery range and the La Loma Street bridge. Along that trail, I noticed many instances of what looked like old plantings of native species and many new (and old) examples of infrastructure put in place for one purpose or another. Observationally, it made for an interesting mix of very old, somewhat old, and new objects with both obvious uses and more obscure ones lost to time.

I started the excursion at the riparian creek side to take in the environment. Week to week I can see how things have changed in large and small ways. Small, such as trash and detritus debris from water releases down the channel, animal carcasses that are there one week and gone the next and other trash debris that moves with the flow of water and people in the space.

In this space, the presence of longer-term human impact is harder to see once you travel 20 yards from where the concrete water channel ends and the natural space begins. You can see the same, further down at the dam and spillway and at the larger bridges that span like giant cliffs up into the sky. These are definitely “man-made” objects and fit the anthropogenic definition of human placement in the space. And yet, they exist in the same way mountains do—monolithic, unmovable, and stoic. They exist and impose themselves in a way literally shapes the space around them. Manmade but beyond simple comprehension.

The riparian space in the Lower Arroyo is full of human made objects with concrete conglomerate cast-offs. Trash and daily life ephemera–masks and food containers abound here. Mixed into this matrix are leaves, logs and other “organic” leftovers and cast offs.

Of note in the space, was the geologic composition under the creek. RockD lists it as Quaternary/alluvium – old unit 3, late Pleistocene. In makes sense given the aspect of flowing water and the ability to send it into aquifers or at least down into the soil. It may not be much, but it’s better than letting it (now) run off into the sea.

Walking the space, I was pressed to grasp fully how past indigenous peoples would have used it year-round. My conclusion was that they wouldn’t have. The riparian creek side would be a great fishing spot when fish were running. It would have also been a nice place to escape the heat or gather water. The vegetation would also be good sources for building or crafting materials (reeds, staves, ETC.). Also, as places to bathe, track and trap animals who come down to drink from the edges.

Read: Becoming A Naturalist

Following the creek, I crossed at the flat wash under the 134 freeway. On the west bank. I followed the creek down to the dam finding several new plants, not observed on more park like east side. This space was much more “natural” and less manicured. Plus, it seemed to represent more of the natural look and feel with oak forest and sage scrub mixing and mingling together. Some of the interesting plant species I found here included a Turkey-tail fungus, a coastal prickly pear cactus, both nestled out of view from a common path.

Further down this path, the geology turned into Mesozoic biotite, firmer and older then in the more vegetive riparian area further north. The strata under the surface were likely less eroded and deep, not collecting as much sand and small stone run-off.

This path, from the dam down the trail to the archery range was a mix of chaparral and oak nestled between meadows along a meandering path along the western bluffs. Both above and below were signs of human occupancy jutting out from the ground. On one spot, old river rock walls and rail boulders snaked along the trail. In others, new post erected by Boy Scouts marked an empty archery range. And yet more in this space, relics of old constructions for unknown buildings sit hidden from view from the trail but scrawled with graffiti telling us we’re moving into “Wendy’s World.”

Not much father along the path were more modern monoliths including a spiral maze arranged out of found and collected rocks, hearts and a smiling face. All could have been days old or the productive of some creative force from millennia ago. One can’t help to wonder if those same activities parallel those indigenous peoples from centuries past—spending idle time in the canyon between foraging or moving between spaces.

That movement seemed to be the dominant feeling in the Lower Arroyo park. The space is anything but static: birds darting to-and-fro, lizards scurrying into brush and detritus, pack rats skulking about, all while larger animals hide in shadows to escape the midday heat or travel through and above the arroyo on monolithic bridges spanning the gap. The Lower Arroyo Seco was alive and abuzz with life and the movement of life within it.

Field Observations

• Riparian/chaparral/oak Forest ecosystems
• West Arroyo wall, many more bird and plant species (a much greater diversity)
• Old stone walls/roads, architecture without buildings
• New and not-so-new archery posts
• Far fewer people than on the east side
• More park-like infrastructure:
  • Steps
  • Fountains
  • Hay bales (archery range)
• A trail cam
• Many man-made arches in the space (bridges) spanning the park.

Observed Species

Observed Plants

• Black Mustard – Brassica nigra
• California Buckwheat – Eriogonum fasciculatum
• California Buckeye – Aesculus californica
• chapparel bush-mallow – Malacothamnus fasciculatus
• Chapparel Whitethorn – Ceanothus leucodermis
• Coastal Prickley Pear – Opuntia littoralis
• Elderberry – Sambucus melanocarpa
• Horehound – Marrubium vulgare
• Hummingbird Sage – Salvia spathacea
• Laurel Sumac – Malosma laurina
• Lemonade Berry – Rhus integrifolia
• Poison Oak – Toxicodendron vernix
• Spiny Redberry – Rhamnus crocea
• Sugar Bush – Rhus ovata
• Toyon – Heteromeles arbutifolia
• Turkey Tail Mushroom – Trametes versicolor
• White Sage – Salvia apiana
• Wild Cucumber – Chilicothe Marah macrocarpa
• Oak Trees several/various
• Weeds (many)

Observed Animals

• California Thrasher – Toxostoma redivivum
• California scrub jay – Aphelocoma californica
• House wren – Troglodytes aedon
• Hover flies Mosquitos Rabbits Sparrows
• Western fence Lizard – Sceloporus occidentalis
• Woodpecker – Melanerpes formicivorus(?)
• Gnats