Trees In Spring

Spring is a wonderful time to observe trees. After a long, dreary winter they burst into action. For many species, spring is the time for reproduction.

Species in this episode:

-Serviceberry (Amelanchier sp.)

-Norway maple (Acer platanoides)

-Eastern redcedar (Juniperus virginiana)

-Sugar maple (Acer saccharum)

-Saucer magnolia (Magnolia x soulangeana)

Producer, Writer, Creator, Host: Matt Candeias (http://www.indefenseofplants.com)

Producer, Editor, Camera: Grant Czadzeck (http://www.grantczadzeck.com)

Early Spring Botanizing

SURPRISE!

Many have commented that a video component was lacking from the hiking podcasts. I have teamed up with filmmaker/producer Grant Czadzeck (www.grantczadzeck.com) to bring you a visual botanizing experience. I'm not sure how regular this will become but let us know what you think. In the mean time, please enjoy this early spring hike in central Illinois.

Spring Has Sprung Earlier

Phenology is defined as "the study of cyclic and seasonal natural phenomenon, especially in relation to climate, plant, and animal life." Whether its deciding when to plant certain crops or when to start taking your allergy medication, our lives are intricately tied to such cycles. The study of phenology has other applications as well. By and large, it is one of the best methods we have in understanding the effects of climate change on ecosystems around the globe. 

For plants, phenology can be applied to a variety of things. We use it every time we take note of the first signs of leaf out, the first flowers to open, or the emergence of insect herbivores.  In the temperate zones of the world, phenology plays a considerable role in helping us track the emergence of spring and the onset of fall. As we collect more and more data on how global climates are changing, phenology is confirming what many climate change models have predicted - spring is starting earlier and fall is lasting longer.

Researchers at the USA National Phenology Network have created a series of maps that illustrate the early onset of spring by using decades worth of data on leaf out. Leaf out is controlled by a variety of factors such as the length of chilling temperatures in winter, the rate of heat accumulation in the spring, and photoperiod. Still, for woody species, the timing of leaf out is strongly tied to changes in local climate. And, although it varies from year to year and from species to species, the overall trend has been one in which plants are emerging much earlier than they have in the past.

https://www.usanpn.org/data/spring

For the southern United States, the difference is quite startling. Spring leaf out is happening as much as 20 days earlier than it has in past decades. Stark differences between current and past leaf out dates are called "anomalies" and the 2017 anomaly in the southern United States is one of the most extreme on record.

How this is going to alter ecosystems is hard to predict. The extended growing seasons are likely to increase productivity for many plant species, however, this will also change competitive interactions among species in the long term. Early leaf out also comes with increased risk of frost damage. Cold snaps are still quite possible, especially in February and March, and these can cause serious damage to leaves and branches. Such damage can result in a reduction of productivity for these species.

Changes in leaf out dates are not only going to affect individual species or even just the plants themselves. Changes in natural cycles such as leaf out and flowering can have ramifications across entire landscapes. Mismatches in leaf emergence and insect herbivores, or flowers and pollinators have the potential to alter entire food webs. It is hard to make predictions on exactly how ecosystems are going to respond but what we can say is that things are already changing and they are doing so more rapidly than they have in a very long time. 

For these reasons and so many more, the study of phenology in natural systems is crucial for understanding how the natural world is changing. Although we have impressive amounts of data to draw from, we still have a lot to learn. The great news is that anyone can partake in phenological data collection. Phenology offers many great citizen science opportunities. Anyone and everyone can get involved. You can join the National Phenology Network in their effort to track phenological changes in your neighborhood. Check out this link to learn more: USA National Phenology Network

Further Reading: [1] [2]  

 

Spring Surprise on the Tallgrass Prairie

I have no frame of reference for spring on the tallgrass prairie. Everything is new to me. It is amazing to see what starts to come up before all of the grasses wake up and make things a lot harder to find. Diminutive herbs take advantage of sunlight while they can. What I also like is how well certain species stand out against a backdrop of last year's dry stems. This is how I was able to find wild hyacinth (Camassia scilloides). 

The first time I laid eyes on this species, I was actually looking for birds. The spot I was in is known for harboring pheasants. I could hear the males calling but I was having a hard time locating these colorful birds. As I scanned the prairie for shots of color, something else caught my eye. From where I was standing, it looked like a green stick covered in foam. I couldn't quite make out enough detail. I knew it had to be a plant but the search imagine simply wasn't there. I had to investigate. 

Gingerly I tip toed out into the grasses trying to avoid stepping on emerging vegetation. Luckily some deer had already beat a path pretty close to where this mystery plant was growing. When I was only a few yards away I quickly realized what I was seeing. It was a small patch of wild hyacinth. From a distance it was hard to resolve the outline of the tightly packed flowers. From up close, however, it is one of the most stunning spring displays I have ever seen. 

They were covered in ants. As it turns out, these flowers produce copious amounts of nectar. Whereas ants offer nothing in the way of pollination, myriad other insects like flies, bees, butterflies, and wasps visit these blooms in search of a sweet, energy-rich meal. This plant seems to have no trouble getting pollinated. This is a spring species, emerging from an underground bulb not unlike the hyacinths you buy at nurseries. It has slender, grass-like foliage that isn't always apparent mixed in with all of the other vegetation. 

I was a little surprised that such an obvious plant could exist unharmed so near a deer path until I did some research. Like many of its relatives, wild hyacinth is quite toxic to mammals. As such, the deer were smart to pass it up. After years of seeing nothing but its introduced Asian relatives, I was quite happy to be meeting an eastern species native to North America. 

Further Reading:

http://bit.ly/1NBPF9z

Throwing it to the Wind

Though many of you may be cursing this fact, in the temperate regions of the north, wind pollinated trees are bursting into bloom. Their flowers aren't very showy. They don't have to be. Instead of relying on other organisms for pollination, these trees throw it to the wind, literally.

It is an interesting observation to note that the instances of wind pollinated tree species increases with latitude and elevation. This makes a lot of sense. It is most effective in open areas where wind is at its strongest. That is why many wind-pollinated trees get down to business before they leaf out.

 

 

 

The fewer obstructions the better. Also, pollinators can be hard to come by both at high elevation and high latitudes. Therefore, why not let the wind do all the work? This is also why wind-pollination is most common in early succession and large canopy species. Similarly, this is also why you rarely encounter wind-pollinated trees in the tropics. Leaves are out year round and pollinators are in abundance.

Without pollinators, wind-pollinated trees don't need to invest in showy flowers. That is why they often go unnoticed by folks. Instead, they pour their energy into pollen production. Your irritated sinuses are a vivid reminder of that fact. Wind pollination is risky. It relies mostly on chance. Therefore, the more pollen a tree pumps out, the more likely it will bump into a female. However, some trees like red maples (Acer rubrum) combine tactics, relying on both wind and hardy spring pollinators for their reproduction.

Whether you love this time of year or dread it, it is nonetheless interesting to see how static organisms like trees cope with the difficulties of sexual reproduction. I enjoy sitting in my yard and watching pines billow pollen like smoke from a fire. If anything, it is a stark reminder of how important sexual reproduction is to the myriad organisms on this planet.

Further Reading:
http://bit.ly/1qnRUm2