Week of May 27, 2022
It's calving season! We ran across this new born baby elk. It was still wet from its mama licking it. Once we were able to spot it (which is tricky because the babies lay perfectly still and they have such excellent camouflage), we backed away quietly and gave it a wide berth as to not disturb mama and baby.
Photo credit: Ron Deckert
Location: Near Flagstaff, AZ, USA
Week of May 13, 2022
Here's an example of sympatric evolution. These two species of Phlox grow side by side in the dryland forests of Northern Arizona. Sympatric evolution occurs when natural selection acts on individuals of the same population in different ways, eventually leading to entirely new species while remaining in the same area. The distance between the petals of these wildflowers must attract different sets of pollinators.
Photo credit: Julia Hull
Location: Near Flagstaff, AZ, USA
Week of April 22, 2022
Photo credit: Julia Hull
Location: Flagstaff, AZ, USA
Week of April 15, 2022
Photo credit: Julia Hull
Location: Near Flagstaff, AZ, USA
Week of April 8, 2022
Photo credit: Julia Hull
Location: Near Flagstaff, AZ, USA
Week of April 2, 2022
Photo credit: Julia Hull
Location: Near Flagstaff, AZ, USA
Week of March 26, 2022
This week in my introductory biology lab, the students were learning about "spore plants" such as bryophytes (mosses, liverworts, and hornworts) and ferns and their allies. These ancient lineages of plants depend on water for sexual reproduction. Even in the desert, mosses can be abundant. Desert mosses play an important role in ecosystem function. For example, these desert mosses are photosynthesizing before most of the grasses and forbs have even germinated!
My dogs think mosses are amazing too!
Photo credit: Julia Hull
Location: Near Flagstaff, AZ, USA
Week of March 19, 2022
The Mexican cordon (Pachycereus pringlei) might initially look similar to the saguaro cacti iconic of the southwestern United States. However, cardon are taller than saguaros. The tallest cactus ever recorded was a cordon at 60 feet (~19 meters). Cordon also tend to have branches in more abundance and closer to the ground. To my eyes, the surface of cordon looks smoother than saguaro and there is definitely a difference in the spines of saguaro and cordons.
Cordon host beneficial bacteria that can "fix" nitrogen from the atmosphere, which requires a lot of energy. However, this seems to be worth it as nitrogen is the limiting factor of plant growth. Cordons also host beneficial fungi that can help them obtain water and nutrients from very small pockets of soil. The combination of bacterial and fungal symbionts allows cordons to live long lives in harsh conditions.
Photo credit: Julia Hull
Location: Desert Botanic Garden, Phoenix, AZ, USA
Week of March 11, 2022
My introductory biology students at Northern Arizona University are learning about the kingdom of fungi this week. One of the other graduate students in my research lab found these cup fungi (likely Peizia sp.) living in the moss that is a greenhouse "weed". Fungi in the phylum ascomycota produce 8 sexual spores held in a sack called an ascus and released simultaneously.
Photo credit: Julia Hull
Location: Flagstaff, AZ, USA
Week of March 4, 2022
The average March snowfall in Flagstaff, AZ in my lifetime (pushing 40 years now), is 13.9 inches (~35 cm). But just like everything in climate related in the southwest, it isn't the mean that matters most--it is variability. In many years, there was no snowfall in March, but in some years there was well over 3 feet (just shy of 100 cm)! This is was the first big snowfall of March 2022, when we received about 4 inches (10 cm).
Photo credit: Julia Hull
Location: Near Flagstaff, AZ, USA
Data retrieved from weather.gov
Week of February 26, 2022
The Colorado River is the lifeline for the southwestern United States for humans and essentially all other organisms living in the desert southwest. This photo was taken above Glen Canyon Dam on the border of Utah and Arizona. The native willows and invasive tamarisk in this photo are still in their winter dormancy. Leaves will likely start to emerge in about a month.
Photo credit: Julia Hull
Location: Near Moab, UT, USA
Week of February 19, 2022
This is a extremely thin slice of potato under a compound light microscope (400X magnification). My introductory biology students used iodine to stain starch molecules a dark bluish-purplish-blackish color. Almost instantly, the organelles that store starch, amyloplasts, became visible as purple circles.
Photo credit: Julia Hull
Location: Flagstaff, AZ, USA
Week of February 12, 2022
My introductory biology students at Coconino Community College have been exploring cellular structure and function. Here is the aquatic plant Elodea under a compound microscope (400X magnification). The boxy rectangles are the plant cells, and the little round green circles are the chloroplasts. Chloroplast an organelle bound by double membranes and contain their own DNA that is different from the nuclear DNA of the plant itself.
Photo credit: Julia Hull
Location: Flagstaff, AZ, USA
Week of February 5, 2022
Sadie and her sister, Maggie (laying down chewing a bone behind Sadie), love exploring the ponderosa pine forests of northern Arizona. Yes, this is just me showing off my cute dogs.
Photo credit: Julia Hull
Location: Near Flagstaff, AZ, USA
Week of January 29, 2022
Habitat in the American southwest is highly variable. To illustrate this, here is a photo I took of a wash in the forest by my house. The south-facing slope is free of snow and it feels like Spring; however, just across the creek, on the north-facing slope, the snow covered ground has the feeling of winter still.
Photo credit: Julia Hull
Location: Near Flagstaff, AZ, USA
Week of January 15, 2022
Although this prickly pear (Opuntia sp.) plant look dead, it is actually just fine. Cacti are well-known for their high water content, which is rare for desert plants. When they are full of water, they appear plump and turgid. Most cacti have anatomy that allows their bodies to shrink and swell, depending on water availability, without causing structural harm. Trouble might happen if the water inside the plant body freezes. So, cacti that live in where freezing temperatures happen regularly and/or for long time periods, such as this guy, actively remove water from the above-ground portions of the plant to prevent cellular damage due to ice formation. This gives them this droopy, sad look. But, once spring comes and the threat of frost has passed, this cactus will likely swell up with water again and regain its erect appearance.
Photo credit: Julia Hull
Location: Near Flagstaff, AZ, USA
Week of January 8, 2022
The ponderosa pine forests of northern Arizona are home to the adorable Abert squirrels (Sciurus aberti). In the winter, when food is scarce, they will prune the tips of the pine branches. After the branches fall to the ground, the squirrels will harvest the female pine cones and/or eat the buds. A sight such as this is a tell-tale sign that squirrels are frolicking in the woods.
Photo credit: Julia Hull
Location: Near Flagstaff, AZ, USA
Week of January 1, 2022
Happy New Year!
The doggies have been enjoying the new layer of Zoom Enhancement Substance!
Snow water equivalent is often more useful than snow depth for hydrologists to measure the amount of water entering the ecosystem. New snow fall vary in density between 3-20%.
Photo credit: Julia Hull
Location: Near Flagstaff, AZ, USA
Week of December 25th, 2021
One of my favorite memories as a kid was going to the Christmas tree lot to pick out our family Christmas tree. I loved the smell of resin and comparing the texture of the needles of spruces, firs, and pines. I would feel sad, though, that the hundreds of trees gave their lives for us to enjoy for a few weeks and then place out on the curb for trash collection. As an undergrad studying botany, however, I learned that those trees didn't actually die to become the canopy for the fabled Santa Claus' presents.
Many conifers have strong apical dominance, which simply means that most of the growth occurs at the apex (or the top), which means that the tree gets taller rather than bushy. Now when the top of the tree gets damaged somehow, like what happened to this ponderosa pine (Pinus ponderosa), one of the lateral buds will grow upward to form a new leader. Where that branch bends is called compression wood. It has different physical and chemical makeup than regular wood and is less desirable as lumber. However, these traits of apical dominance and compression wood allow for Christmas tree farmers to simply cut the top of the tree to sell. The lower branches will bend upward by creating compression wood. In a few years, that new leader will be ready to harvest and sell. So, those trees in the tree lot live on. And maybe in a few years, you'll pick a tree that is actually the same individual as this year's tree.
Photo credit: Julia Hull
Location: Near Flagstaff, AZ, USA
Week of December 18th, 2021
As climate change progresses, we expect to see more strange circumstances such as this buttercup (Ranunculus spp.) flowering in the "wrong" season. The timing of flowering is controlled by genetic and environmental controls; such as soil moisture, day length, and temperature. Apparently, environmental conditions on December 14th were appropriate for this buttercup to flower. This species typically flowers in early March. The insects that act as pollinators for this species are likely not present at this time of year (I haven't seen any bugs for a few months).
This system shows the potential for uncoupling of the phenology of symbionts. Phenology is the fancy science word for the timing of cyclic or seasonality of life events, such as flowering time, egg emergence, migrations, and the like. Symbionts, such as flowering plants and their pollinators, might have different phenological signals. As climate change progresses, conditions like temperature and soil moisture are likely to change, but other signals, such as daylength, will not change. Depending on how dependent the symbionts are to each other, uncoupled phenology has the potential to be highly detrimental to the continuation of one or both species.
Photo credit: Julia Hull
Location: Near Flagstaff, AZ, USA
Week of December 11th, 2021
The more we explore the forest near our house, the more weird stuff we find. Although it has not be confirmed, we have seen several trees that we expect are hybrids of Arizona cypress (Cupressus arizonica) and Alligator junipers (Juniperus deppeana). The male cones, the bark, the foliage, the tree architecture, and other traits of the suspected hybrids appear as intermediate of each parental species. Typically, Arizona cypress live at slightly lower elevations than the ponderosa pine forest of northern Arizona. However, the cypress and suspected hybrids we've found are on the edge of a canyon which may act as a migratory corridor of these typically lower elevation species.
Photo credit: Julia Hull
Location: Near Flagstaff, AZ, USA
Week of December 4th, 2021
Plant lifecycles are very different from what us animals do. Plants use the Alteration of Generations found in sporic meiosis. This means that plants have a multicellular diploid phase (where each nucleus contains at least two copies of each chromosome) AND they have a multicellular haploid phase (where each nucleus contains half the number of chromosomes). The multicellular haploid generation is known as the gametophyte, because it is the plant (-phyte) that makes gametes (gameto-). In seed plants, there are female and male gametophytes. Female gametophytes make female gametes (eggs) and are called megagametophytes. Male gametophytes produce sperm and are called microgametophytes, or the easier-to-remember name of "pollen".
Pictured here are the male cones of an alligator juniper (Juniperus deppeana). This is where the pollen, or the microgametophytes, are produced.
Photo credit: Julia Hull
Location: Near Flagstaff, AZ, USA
Week of November 27, 2021
We've noticed a lot (A LOT) of baby alligator junipers in the forest near our home, but we never could find any mature ones. We wondered where all these seedling could be coming from...until we stumbled across this old boy we named "Uncle Jun". Alligator junipers have an interesting bark pattern that looks similar to the scales on the backs of alligators, hence the common name.
Photo credit: Julia Hull
Location: Near Flagstaff, AZ, USA
Week of November 20, 2021
Wood decay fungi produce specialized enzymes that can break apart the complex molecules that constitute wood, namely cellulose and lignin. There are three major types of wood decay: soft rot, white rot, and brown (or cubic) rot. This unidentified fungus seems to be a brown rot fungus.
Photo credit: Julia Hull
Location: Near Flagstaff, AZ, USA
Week of November 13, 2021
The temperate rain forest of the Pacific Northwest is a very different ecosystem than the dry forests of the southwestern US where I live. I spent most of my trip to Portland admiring the moss, ferns, and lichens that gave the forest a green glow even in late autumn.
Photo credit: Julia Hull
Location: Portland, OR, USA
Week of November 6, 2021
Paper beats rock. Trees and shrubs, such as this gambel oak (Quercus gambelii), undergo secondary growth to increase the girth of their trunks and branches. Over decades, the secondary growth of this oak trunk has pushed these rocks farther apart.
Photo credit: Julia Hull
Location: near Flagstaff, AZ, USA
Week of October 30, 2021
Terrestrial and aquatic ecosystems are linked through seasonal nutrient cycling. In the autumn, leaves that fall into lakes, ponds, and streams add important nutrients in those aquatic systems. Insects, amphibians, bacteria, and other critters in the water use those nutrients for growth and reproduction. Some aquatic insects that live in the water as larvae, but leave the water after they metamorphize and become winged adults. These insects are an important food source (and might be more nutritious than terrestrial insects) for terrestrial bird species.
"When we try to pick out anything by itself we find that it is bound fast by a thousand invisible cords that cannot be broken, to everything in the universe."
--John Muir
Photo credit: Julia Hull
Location: near Flagstaff, AZ, USA
Week of October 23, 2021
The oaks are showing their fall colors!
Photo credit: Julia Hull
Location: near Flagstaff, AZ, USA
Week of October 16, 2021
One of my favorite things about living in a dryland forest is when riparian (streamside) habitats adjoin desert habitats. This community of mosses and lichens is found on the north facing cliff wall while the agave feature last week are directly across the canyon on the south facing cliff wall. Mosses, like other bryophytes, are one of the oldest known land plants. They maintain some of the ancestral traits of the common ancestor to all terrestrial plants. Mosses and other bryophytes lack true vascular tissue and therefore do not grow tall. Their reproduction is also dependent on water, as their sperm cells need to swim to get to the eggs. This means that moss and their allies are often found in cool, moist places. In dry places like Arizona, that means that they are often found in cool, moist microhabitats, such as the seep in a north facing rocky cliff.
Photo credit: Julia Hull
Location: near Flagstaff, AZ, USA
Week of October 9, 2021
These Agave parryi are found on the south facing slope of a rocky canyon just south of Flagstaff, Arizona. The common name of century plant was coined because they were thought to flower only once per hundred years. However, that is a misnomer. This species flowers at about 10 to 15 years of age, but this does mark the end of the plant's life. Plants that flower once in their lifetime are called monocarpic, which literally means "once flowering". The flower stalks are impressive. While these agave only sexually reproduce once in their lifetime, they are almost always asexually reproducing by producing clonal "puppies" or rosettes at the base of the plant.
Photo credit: Ron Deckert
Location: near Flagstaff, AZ, USA
Week of October 2, 2021
This male tarantula's (Aphonopelma sp.) hunt for a female was interrupted by a curious biologist and her bumbling dog. Often seen during the summer rainy season or in early fall, as is the case here, male tarantulas are easily spotted in the ponderosa pine forests of northern Arizona. Females are rarely seen because they do not frequently leave their burrows. Females are a little larger with stouter bodies than males. While they do have a mild venom, their primary defense is to fling the urticating hairs on their abdomen into the face of their would-be predator. Armed with a sharp barb on the end, the hairs dig and irritate the skin, eyes, and nose of the creature threatening them. As I was taking this photo, one of my dogs walked over this guy and he flung those hairs into my face. Fortunately, I was wearing sunglasses at the time so my eyes were protected. I was itchy for a few hours, but no worse for wear.
Photo credit: Julia Hull
Location: near Flagstaff, AZ, USA
Week of September 25, 2021
Silene laciniata ssp. greggi is has several common names, including Mexican silene, Mexican campion, catchfly, and others. There are eight species of Silene in Arizona, USA. This particular variety is found in the understory of coniferous forests from elevations 5500-9000 feet (~1700-2700 m) above sea level. This is a classic hummingbird pollinated flower. Its red color attracts hummingbirds and the long tube contains nectar that is accessible to critters with long beaks or tongues such as hummingbirds. Other species in the genus Silene have flowers that have co-evolved with other pollinators, such as the bladder campion (S. vulgaris) native to Europe and pollinated by long-tongued bees and moths.
Photo credit: Julia Hull
Location: near Flagstaff, AZ, USA
Week of September 18, 2021
The southwest dwarf mistletoe (Arceuthobium vaginatum cryptopodum) is a parasite found on the Rocky Mountain variety of ponderosa pine (Pinus ponderosa var. scopulorum). Dwarf mistletoe infect pines when their seeds are forcefully ejected from the fruits, travel up to 45 feet (~13 m), and land in the branches of another tree. The seeds germinate and infect the bark and wood of their pine host. Mistletoe obtain all of their water and nutrients from their host, as well as most of their sugars, although mistletoe does retain some its chlorophyll and does some photosynthesis. Pitch is sometimes produced as a tree defense against mistletoe infection, as seen here. The trees increase resin production that pushes the mistletoe plant out of the tree’s wood and bark. Mistletoe can also result in abnormal tree growth, reduced vigor, and lower cone production.
Photo credit: Julia Hull
Location: near Flagstaff, AZ, USA
Week of September 11, 2021
The wandering garter snake (Thamnophis elegans vagrans) is one of five recognized subspecies of western garter snakes. This subspecies is widely distributed, ranging from Oklahoma to California and north into the Canadian providences of British Columbia, Alberta, and Saskatchewan. It can be found in forest meadows and grasslands, but are most abundant in riparian areas, such as this human-made pond just outside Flagstaff, Arizona. Garter snakes and their relatives are ovoviviparous, meaning that the eggs remain inside the mother's body until they hatch.
Photo credit: Julia Hull
Location: near Flagstaff, AZ, USA
Week of September 4, 2021
Despite the arid environment that characterizes most of Arizona, there are 24 species of native frogs and four species of non-native frogs that call Arizona home. The Arizona native northern Leopard frog (Lithobates pipiens, syn. Rana pipiens) featured here, is one of those. While historically widespread throughout the US and Canada, the northern Leopard frog is experiencing great reduction in population size due to suitable habitat loss, especially in Arizona where riparian and wetland habitats are disproportionately threatened. In Arizona, Northern Leopard frogs are limited to man-made earthen bound water holes, known as tanks, in Coconino county. Invasive bullfrogs and crayfish also prey on the adults and tadpoles of this species, further threatening the future of the species.
Photo credit: Julia Hull
Location: near Flagstaff, AZ, USA
Week of August 28, 2021
The Advanced Placement Biology students at the local high school are setting up an experiment the combined effects of tamarisk (Tamarix spp.) legacy soil and drought on coyote willow (Salix exigua) performance.
Using tamarisk and non-tamarisk legacy soil collected from a common garden and willows collected from our partners at the US Geological Survey, students set up an experiment that asks the question "How will the combined effects of drought and tamarisk legacy soil affect coyote willow survival and growth?". This experiment will be the anchor for the concepts being discussed in their course. At the end of the school year, these willows will be destructively harvested for additional biometrics.
Photo credit: Julia Hull
Location: Flagstaff, AZ, USA
Week of August 22, 2021
My kid and I collected about 1,000 pounds (~454 kg) of soil for an experiment we are setting up at the local high school. The Advanced Placement Biology students at the local high school will be setting up an experiment the combined effects of tamarisk (Tamarix spp.) legacy soil and drought on coyote willow (Salix exigua) performance.
We collected soil from a common garden established in partnership with Northern Arizona University's Southwestern Experimental Garden Array project and Babbitt Ranches. At this site near the Little Colorado River, just outside of Cameron, AZ, the highly invasive tamarisk plant was removed and native Fremont cottonwoods (Populus fremontii) and coyote willows were planted in an effort to restore the riparian (streamside) ecosystem here. Tamarisk increases the salinity and nitrogen levels of the soil, while reducing the number and types of beneficial plant associated fungi that cottonwood and willow rely on. And the legacy of these effects remain for years after tamarisk is removed. This site is ideal for testing the effects of tamarisk legacy soil on cottonwoods and willows, because there is one portion of this site that did not have tamarisk due to mining sand.
Photo credit: Julia Hull
Location: Outside Cameron, AZ, USA
Week of August 14, 2021
Lobster mushrooms are easily distinguished by their bright orange coloration, similar to the color of a cooked lobster. They also, apparently, have a similar taste and texture as lobster, although I have never tried them personally. Lobster mushrooms result from the fungus Hypomyces lactifluorum in the phylum Ascomycota parasitizing other fungi from the phylum Basidiomycota. This photo shows a Hebeloma sp. in its non-parasitized form (right) and being parasitized by Hypomyces lactifoluorum (left). The parasite alters the secondary metabolism of the Hebeloma (common name is "poison pie"), resulting in the otherwise toxic mushroom to become a highly sought delicacy.
Photo credit: Julia Hull
Location: Outside Flagstaff, AZ, USA
Week of August 7, 2021
The genus Amanita houses some of the most deadly mushrooms; however, Caesar's mushroom (Amanita caesarea, Amanitaceae) is one of the largest and a rare edible species in this genus. It is highly prized in western Europe and is legend to be a favored dish of the Caesar family of Roman Empire fame. The North American range of this species is limited to the pine forests of Mexico, Arizona, and New Mexico. This species is one of many species of fungi that form typically mutualistic relationships with plants, called mycorrhizas. The trees provide sugars made through photosynthesis in exchange for water and nutrients the fungi acquire in from the soil. Pines are obligate to mycorrhizal fungi, meaning that without mycorrhizal fungi pine seedlings die within weeks of germination.
Photo credit: Julia Hull
Location: Outside Flagstaff, AZ, USA
Week of August 1, 2021
Horsemint bee balm, Monarda menthifolia (Laminaceae), are frequently visited by bumblebees, butterflies, and other charismatic pollinators in the intermittent streams of the ponderosa pine forests in northern Arizona. These striking plants bloom during monsoon season (July-August). Their leaves give off a strong mint smell when crushed.
Photo credit: Ron Deckert
Location: Outside Flagstaff, AZ, USA