Storms and juniper cones

Back in early October northern Arizona experienced a severe storm system that lasted a few days and produced 4-5 confirmed tornadoes in one morning just to the west and south of Flagstaff. A couple of the tornadoes destroyed 30 homes and derailed a train in Bellemont (just west of Flagstaff on I-40). The tornadoes uprooted and snapped trees for several-mile swaths of neighboring forest. Surprisingly Arizona averages around 4 tornadoes per year, but I think this set the record for tornadoes in a single day. I guess the reason we rarely hear about tornadoes in the state is that most occur in very rural areas and so few people see it (the local news stations also rarely report on anything not affecting Phoenix, Tucson, or Flagstaff).

Two days before the tornadoes, our field ecology class went out on our second trip to Strawberry Crater northeast of Flagstaff (north of Sunset Crater National Monument, east of Hwy 89). For our second project our crew was initially doing a follow-up of an unpublished study done in this class in 1992 that looked at whether or not the large powerlines running through the site were providing additional stress to that of the poor-growing conditions of the cinder soils that were causing one-seed junipers (Juniperus monosperma) to have two-seeded cones. Producing more than one seed is due to "polyembryony", which is the production of additional embryos, which may have below-average seed weights. Typically, lower seed weight infers that the seed may not be viable, as weight is a measure of the amount of food that the growing embryo has to feed on before it can sprout and deal with environmental stresses below and above ground. By the way, junipers appear to have "berries", but they are actually fleshy cones with fused-together scales. We ended up not seeing a difference in the frequency of double-seeded cones growing under the powerlines vs. varying distances away from the powerlines. We initially presumed that the severe effects of the recent drought masked any effects of the electromagnetism that the 1992 study implicated as being an additional stressor causing the cone abnormality. As we continued through our study, we noticed other strange cone and seed features that made us rethink our research questions/hypotheses (discussed below). During this trip at the beginning of the storm system, we encountered lots of lighting and some brief downpours. It really made us feel safe sampling junipers below powerlines with lightning fairly close by! The lightning was cool to watch off to the west, as the sunset behind the clouds made the lightning have a pink-purple hue to it. Here are some photos of the site with the storm moving through:

Blurry, but spooky picture:

The storms also dumped some snow on the higher elevations of the San Francisco Peaks above Flagstaff. Here are some shots from NAU and from north of Strawberry Crater to the northeast of the peaks:

 

So, after the powerline hypothesis didn't seem to be providing any pattern, we revised our study and decided to compare cones of junipers across an elevation gradient and between two different soil types (the cinder soils around Strawberry Crater and the more limestone soils east of Flagstaff near Cosnino). Along with looking at the frequency of two-seeded cones, we also noticed many of the cones on some trees having a peeled-back look, where the seeds were protruding out of the fleshy cones. Looking in the literature, a few old studies had discovered that this feature is called "gymnocarpy" and is caused by insect larvae invading the immature cones before the embryos are fully-developed. Typically gymnocarpous cones have infertile seeds. In addition, we noticed a high proportion of junipers with parasitic mistletoe (Phoradendron juniperinum), which we decided to quantify frequency of as we suspected it to be an additional stressor that could lead to higher numbers of two-seeded cones.

After quantifying these features, we finally started seeing some patterns. Two-seeded cones were more frequent on the very-stressed cinder soils than the less-stressed limestone soils. Frequency of gymnocarpy and mistletoe appeared to be correlated with elevation, having a higher frequency at lower elevations. We also found higher seed weights on less-stressed sites. Since the lower elevations where the ecotone between juniper woodlands and grassland are more stressed (less soil moisture, higher temperatures), this higher frequency of fewer viable seeds suggests that the juniper woodland at lower elevations on the Colorado Plateau may be undergoing a range contraction. Recent research looking at potential effects of climate change have suggested that plant communities may shift up in elevation. If droughts become more frequent with warmer average temperatures, then the pinyon-juniper ecotype may move up in elevation over time with higher mortality and decreasing recruitment of new seedlings at lower elevations. Anyways, here are various pictures from the project:

Gymnocarpous cones (note that the one on the left in the first picture has 3 seeds, which is very rare, although other studies have documented 4 seeds in some cones):

juniper mistletoe (Phoradendron juniperinum):

one-seed junipers (Juniperus monosperma) growing on cinder soils:

Ecotone between juniper woodland and rangeland:

Of course, whenever you do a field project you end up encountering a lot of other great stuff besides what you're directly studying. While I didn't get any good photos of birds there, we saw lots of Pinyon Jays and migrating Sage Thrashers in the pinyon-juniper woodlands. One day I almost stepped on a roosting Common Poorwill too (it flushed from right under my foot). Here are some photos of scenery, ancient indian sites, plants, and wildlife seen during our project around Strawberry Crater:

Views of Strawberry Crater, a relatively recent (but extinct) volcano and its cinder field:

 

Arizona gilia (Ipomopsis arizonica), which is related to skyrocket (I. aggregata), but is adapted to growing on cinder soils:

 

 

 

horned-lizard:

Ancient pithouse ruins and pottery shards left by Sinaguan indians:

Rusted coffee can hanging in juniper that a rodent or bird used as a nest:

Insect impaled on barbed wire by Loggerhead Shrike (a predatory songbird). They will impale insects, small birds, lizards, and rodents on sticks, yucca leaves, or barbed wire for later feeding:

purple locoweed (Oxytropis lambertii):

 

Apache-plume (Fallugia paradoxa):

 

View of Hopi mesas and Painted Desert to the northeast of Strawberry Crater:

rubber rabbitbrush (Chrysothamnus nauseosus / Ericameria nauseosa):

Road-kill elk along Hwy. 89:

Dead mouse and halloween-colored beetle that was feeding off it:

 

Noseburn (Tragia nepetefolia), a relative of stinging-nettle, that leaves a burning sensation for a couple hours if you touch it:

One of the other crews from our class was initially doing a study testing aggression in ants by dying some ants with a hot-pink powder and then releasing them into a foreign ant hill. We came across one of these hills and saw some of the dyed ants milling around:

Sunset and Brewer's Blackbirds perched on powerlines against the sunset:

The one day our crew was dropped off north of Strawberry Crater near a roadside trading post so we could sample junipers at lower elevations. So, when dusk came, we ended up waiting at the trading post for our professor and the rest of class to pick us up in the van. While we waited, we checked out some really old wagons next to the parking lot. We also noticed a very bizarre sign across the highway for "Widowsmite Mission". This became an ongoing joke throughout the project, as we weren't sure why the hell a church would want to smite widows. Here are photos of the wagon and the strange sign:

And lastly, here is a group photo of our crew (posing with a bag of juniper cones we were collecting), which besides myself included Jeff and Dana:

Schultz burn area, rodent trapping

The last couple of weeks our crew has been studying rodent density in the Schultz Fire burn area up on Mt. Elden near Flagstaff for our project in the field ecology class we're taking. We used both rodent trapping and food plates to estimate density of rodents in different treatments across the burn area. Parts of the burn area had been seeded from helicopters with bales of straw dropped on top of the seeds in an attempt to prevent erosion of hillsides. The seed mixture used had wheat in it, which is a fast-growing annual grass. While non-native to the area, the Forest Service was put under pressure from Flagstaff residents to do something fast prevent landslides, erosion, and flood damage for those that live down-slope from the burn. So, the treatments at our site that we looked at were burned with seeding, burned without seeding, and unburned patches. Here are some more photos of the burn and these different treatments (the unburned forest is mainly ponderosa pine with some firs mixed in):
Burned without seeding:

Burned with seeding (wheat seeds and straw):

Unburned patches of ponderosa pine and mixed conifer forest:

Previous studies of small mammals in burned areas had shown that rodent populations, especially deer mice, increased in burned areas after fires. After seeing how nuked some of our sites were, we were curious if this increase would hold true here (it did not seem intuitive to us that mice would be able to find food at these scorched earth sites). We predicted that if mice were more abundant in the burned sites than the unburned, that the site that had been artificially seeded would have more mice than the burned site without seeding. So, we set 60 Sherman traps baited with oats at each of the treatments (burned with seeding, burned without seeding, and unburned) to see what the abundance of rodents was out there. The only species we caught was deer mice (Peromyscus maniculatus). As with the previous studies, we found mice way more abundant in the burned sites than the adjacent unburned patches. We also had statistically significant numbers showing that mice were using the seeded burned site more. Here are some photos of the trapping:

We emptied the traps into a large, see-through bag. Then, we had to corner the mouse into part of the bag where it couldn't escape and then pinch the skin on the back of its neck to get a hold of it. Next, we pulled the bag inside out with a grip still on the mouse. We then measured the mouse to determine species. The mice were then released, unharmed, after this to scurry off to the nearest log or rock pile. Here is a photo of Damon and Sam getting a mouse out of a trap, with Damon's dog Denali supervising to make sure the mouse didn't escape prematurely:

My "Abu Ghraib" pose with one of the mice:

Along with the mice trapping, we used food plates to determine what the food availability was like in the habitat. We based it on the concept of "quitting harvest rate", where the food in the plate will be eaten down to the same level as what is available in the habitat based on search pattern and satiation rates by the rodents. This can be used to compare food availability across different sites. We set out 7-15 food plates at the different treatment types. We used petri dishes filled with fine sand and a small amount of cracked corn. Like with the trapping, we also had statistically significant results that showed higher amounts of food in both burned sites than in the unburned site. What was surprising was that the results were similar at both burned sites, which suggests that a similar amount of food is available in the burned site that was not seeded. Possible explanations for this are that lots of native plant seeds have been washed down slope, previously buried seeds have now been exposed, or that invertebrates such as ants have been moving seeds around while recolonizing the burned sites. As far as the fact that mice densities were higher in the seeded vs. non-seeded burned sites despite similar food availability, a possible reason for this might be predation pressure differences (mice at the site without straw would have less features to hide from predators with).  Overall, a pretty cool study! Here are some pics of what the food plates looked like:

Cameron defoliation, petroglyphs

On September 24th I went back up to Cameron (off Hwy. 89 between Flagstaff and Page) in search of rare birds. I did not find any of the previous reported rarities, but lots of migrant songbirds moving through. The most bizarre sighting was of a family group of Lazuli Buntings with one begging fledgling. This seemed extremely late to be finding fledglings of any species here! I checked the Arizona Breeding Bird Atlas and fledgling Lazuli Buntings had only been reported as late as early September in southern AZ. What was even more weird was seeing the adults feeding it already in basic (non-breeding) plumage, with the only blue color remaining on their tails.

While I was down in the seep in the tamarisk thickets along the Little Colorado River below the Cameron Trading Post, I ran into another birder from the Houston area and we scoured the habitat upstream from the bridge. We found a few tamarisks that were completely brown, indicating recent activity by the tamarisk leaf beetles (Diorhabda carinulata). These beetles are native to the tamarisk's range in Eurasia and were released in the western U.S. as a means of biological control of the tamarisk, which is an invader of riparian ecosystems (mostly as a result of disrupted hydrology from damming the rivers). We did not find any of the adult beetles or larvae that day, although other birders had reported seeing a small number of them here. I think the migrating birds moving through may have been the reason we didn't see any of the beetles as I'm sure they are a tasty treat for them. The beetles are already in the Grand Canyon, so I'm sure we'll be seeing more of the beetles moving up the Little Colorado River next year. It would not surprise me if they hit Winslow and Holbrook next summer. The next day I was over in Holbrook and saw some trees that looked like they were being chewed up, but again, did not actually see any beetles (I think they might be here already though). Here are some photos of the trees being defoliated at Cameron:

Besides birding, I also saw some ancient petroglyphs/pictographs up on the low cliffs along the river. I think these might be from either the Anasazi or Sinagua indians (not sure though). The petroglyphs had been damaged by vandals, with other graffiti and some bullet holes on top of the ancient symbols. Here is a photo of petroglyphs:

One weird thing I noticed was that the river looked pretty dry when I arrived around 9:00am, but was flowing good just before I left around noon. There were some structures down on the river that might have been some sort of water regulation devices (maybe water is diverted for agriculture). Some of the dams upstream could have also released water. Here are some comparison photos: