Friday, October 24, 2014

Hard Frost and Milkweed Seeds (23 OCT 2014)

Six times this month the overnight temperature has dropped down below freezing.  Wednesday night the temperature reached down to 28 degrees Fahrenheit (the third time it has reached this low for the month).  When I got to work, the field behind the office was covered with a heavy layer of frost. 

The Common Milkweed (Asclepias syriaca) plants have dropped all of their leaves.  Their seedpods split open releasing the ripe seeds inside.  The field is covered with milkweed seeds and their fluffy parachutes.


The frost covered seeds spent the morning waiting for a breeze to carry them to a new home.


Most of the seeds never make it beyond the field - they snag on plants and other objects along the way.


Even if their silken parachute only carries them a few feet from their parent plant it has done its job of dispersal.   In this way, the parent plant reduces competition from its own offspring and those seeds that do make it further than a few feet become explores capable of colonizing new fields, expanding the species to the physical limits of its range.

Thursday, October 23, 2014

100 Species to Know by Sight - #4 Black-eyed Susan

The next species on my list of 100 species that every kid (and adult) in Mid-Michigan should be able to identify by sight is the Black-eyed Susan (Rudbeckia hirta).  This plant is both common as a wildflower and in gardens.  It can be found across most of the Lower 48 and the southern tier of Canadian provinces.  Because this species is a popular garden plant it can be difficult to determine which populations are native and which have escaped from cultivation. 

Black-eyed Susan flowers
   
Black-eyed Susan can be identified by it dark brown-black, cone-shaped central disc surrounded by 8-20 bright yellow rays (petals).  The flower can be up to 3 inches across.  The plant blooms from mid-Summer into fall.

Black-eyed Susan - note the dark central disc surrounded by bright yellow rays

Black-eyed Susan plants grow up to 2.5 feet tall.  The plants have alternate leaves that can be up to 7 inches long.  The leaves are concentrated on the lower part of the plant's stem.  both the leaves and stems are covered with a dense covering of hair.

Black-eyed Susan - not the alternate leaves and hairy, leafless upper stem

Black-eyed Susan grows in a variety of upland habitats, in both sun and partial shade.  It is a short-lived plant that does well in disturbed habitats.  It is often used in prairie restorations, where it does well for several years before being crowded out by its competitors.

Black-eyed Susan in a prairie restoration
For the previous species in this series of 11 Species to Know by Sight look here.

Wednesday, October 22, 2014

Wildflowers of 2014 - The Flowers I Didn't Find

I went into my Wildflower Big Year with a reasonable expectation of finding 200 species.  In the end, my list ended at 238 species.  When doing a project such as this it helps to have expectations of when and where to find certain things. I know that there are some species of flowers that I will only find in certain places.  Other species can be found everywhere I look.  While I did find some new species this year, it was often the flowers that I did not find that were the bigger surprises.

Thimbleweed (Anemone virginiana): I found the fruits of Thimbleweed, but missed the bloom somehow. 

Thimbleweed - photo from 2008



Common Arrowhead (Sagittaria latifolia):  I found quite a few Common Arrowhead plants, but never saw a single one in bloom this Summer.  This species seemed to be less numerous than in previous years.

Common Arrowhead - photo from 2008


Three-lobed Coneflower (Rudbeckia triloba):  I did not find any Three-lobed Coneflower plants this year.  Normally I find it blooming along the trails in Mill Pond Park.  The mowed area along the trails was widened this year and this species appears to have been a victim of the mower.

Three-lobed Coneflower - photo from 2008

Black-eyed Susan (Rudbeckia hirta):  Black-eyed Susan has never been common in Mt. Pleasant's parks.  The areas where I had previously found it have grown up with much thicker vegetation and the species appears to have been blocked out by its competitors.

Black-eyed Susan - photo from 2007

Butter-and-eggs (Linaria vulgaris):  Butter-and-eggs is a common weed that likes disturbed area.  Like Black-eyed Susan it gets pushed out by thicker vegetation.  The absence of this species was a real surprise.

Butter-and-eggs - scan of a photo from 2005

Cardinalflower (Lobelia cardinalis):  Over the past few years I have been able to reliably find a single Cardinalflower growing in a certain spot in Mill Pond Park.  This year it was not there. 

Cardinalflower - photo from 2009


Large-flowered Bellwort (Uvularia grandiflora):  Large-flowered Bellwort is one of those species that I have found intermittently over they years.  Some years it appears, but more often I do not find it.  In the years that it does show up, it is normally only one or two plants.  This year I didn't find it.  Not really a surprise, but I was hoping to find it.

Large-flowered Bellwort - scan of a photo from 2006

Bladder Campion (Silene vulgaris):  Failing to find Bladder Campion in the parks was also not a huge surprise.  I have only found this species a few times over the past decade.

Bladder Campion - photo from 2008

Indian-hemp or Flowering Dogbane (Apocynum cannabinum):  The lack of Flowering Dogbane can be directly attributed to construction.  I normally find a healthy clump of it growing at the canoe landing at Chipp-A-Waters Park.  This was torn up and covered up during construction this spring.  I hope the plant reappears in 2015.  I have also found the plant growing in a few other places along the riverbank, but trimming right to the river's edge (not really a good practice) kept those populations knocked back this year.

Flowering Dogbane - photo from 2008

White Lettuce (Prenanthes alba):  I think I probably just missed the bloom of this one this year, but I really don't remember seeing many White Lettuce plants earlier in the year.  This plant may just be in a down cycle.

White Lettuce - photo from 2008

Tuesday, October 21, 2014

Wildflowers of 2014 - #238 Witch Hazel

Last Tuesday (14 OCT), I found what will probably be my final wildflower of 2014.

Wildflowers of 2014 - #238 Witch-hazel (Hamamelis virginiana)

Most wildflowers have finished blooming for the year before the Witch-hazel (Hamamelis virginiana) begins to flower.  This native shrub blooms between late September and early November.  In Michigan it is typically the last plant of the year to begin flowering.  Its yellow flowers are pollinated by flies, moths, and beetles.  The plant is also capable of self pollination.  The  flower's narrow petals are up to 3/4 of an inch long.

Witch-hazel flowers

A bee-mimicking fly (upper right) visits a Witch-hazel flower

Witch-hazel is found in the eastern United States and Canada, east of a line from Minnesota south to eastern Texas.  In Michigan, it is found in nearly every county.  It commonly grow to a height of up to 20 feet.  Witch-hazel leaves grow up to 5 inches long and 3 inches wide.  The leaves grow in an alternate pattern on the branches.

The wavy branches of a Witch-hazel plant

Witch-hazel loses its leaves about the same time that it flowers





Monday, October 20, 2014

Fall Forest Ecology

Each of the last three years, 3rd, 4th, and 5th grade students from Winn Elementary have met me at the Chippewa Watershed Conservancy's Audubon Woods Preserve to learn about forests.  This trip always takes place in the spring.  This year, we decided to have the 4th and 5th grade students do both the spring trip and (for the first time) a fall trip.  A major focus of this trip was to have the students identify, draw, and collect leaves for a classroom leaf collection.  Here are a few photos from the day.





Despite some early concerns with the weather, it ended being a beautiful fall day.  In addition to the colorful leaves, fall in Mid-Michigan is the prime time for fungi.



 



One pleasant surprise on the day was finding Sassafras trees growing in the forest understory.  Although this species is found in Mid-Michigan it is much more common further south. 


Friday, October 17, 2014

Earth Science Week - Friday

Happy Earth Science Week!

One of really interesting things to me about Earth Science is that from our point of view many things remain the same, but on a geologic time scale they are undergoing great changes.

Water cuts down through rock forming gorges and canyons.

Watkins Glen, NY

Canyon Falls, Sturgeon River, MI

Rocks crack and tumble becoming smaller and smaller.

Acadia National Park, ME

Acadia National Park, ME

Muskallonge Lake State Park, MI

Sediments build up, forming layers.  Given enough time and pressure those layers turn into rock.

Sleeping Bear Dunes National Lakeshore, MI

Pictured Rocks National Lakeshore, MI

Tectonic forces cause those layers to tilt and solid rock to bend.

Bonanza Falls, MI

LeMoyne State Park, ME

Glaciers carve valleys out of solid rock.
Lake of the Clouds, MI
Through it all, the seasons change.
 
Laingsburg, MI

Isabella County, MI

Mt. Pleasant, MI
 
Mission Creek Woodland Park, Mt. Pleasant, MI

Living things complete their annual cycles.
 
Mt. Peasant, MI

Sleeping Bear Dunes National Lakeshore, MI


And the sun rises and sets daily.

Old Mission Point, near Traverse City, MI

We observe these many changes, but our sense of time is different than that of the Earth and sky.  Earth Science looks at that long view and helps us understand how the many small things that we observe fit into the larger scale of geologic time.

Thursday, October 16, 2014

Earth Science Week - Thursday

Happy Earth Science Week!

A detail of Wagner Falls - one of the more than 200 named waterfalls in Michigan

Today I am going link to 25 different Earth Science posts I have written on this blog.

25 JAN 2013     Weather - Mackerel Skies

20 MAR 2013     Spring

21 JUN 2013     Summer Solstice

27 AUG 2013     Appreciating the Rain

23 SEP 2013     Fall

22 OCT 2013     Geology Photographs

23 OCT 2013     Geology Photographs - Great Lakes Dunes

24 OCT 2013     Waterfalls

30 OCT 2013     Five Science Things - Firsts in American Space Flight

16 DEC 2013     The Face of the Moon (15 December 2013)

21 DEC 2013     Winter Solstice

21 JAN 2014     Geology Concepts - Superposition

22 JAN 2014     Geology Concepts - Original Horizontality

23 JAN 2014     Geology Concepts - Cross-bedding

27 JAN 2014     The Space Shuttle Challenger - Twenty Eight Years Later 

30 JAN 2014     Snow Dunes

04 FEB 2014     Two boulders, both alike in dignity...

19 FEB 2014     Soil Particle Sizes

14 MAR 2014     Four Fossils

20 MAR 2014    Vernal Equinox

21 July 2014     One Small Step

05 SEP 2014     Rainbows

13 OCT 2014     Happy Earth Science Week - Monday

14 OCT 2014     Earth Science Week - Tuesday

15 OCT 2014     Earth Science Week - Wednesday