Local Trees - Part 2

To return to the trees of the Charles Watershed, this post will have more information about the 10 most common trees in my area of the greater Boston area according to the 2021 citywide tree audit. The trees below are in order from most common to least common for my area and I took special note of the ones I could identify as I explored these last weeks.

Honeylocust 

Image source: Peggy Romfh

Common Names: Honey-locust, Honeylocust

Species: Gleditsia triacanthos

Status: least concern, native

Characteristics:

• Grow to heights between 20 to 30 meters
• lifespan of 120 to 150 years
• Each tree produces male and female structures
• Create a 15cm seed pod which are distributed when animals eat, transport, and them excrete seeds along with manure which acts as fertilizer
• Leaves turn yellow in the fall, and appear bright green in warmer months
• Large thorns grow along honey locust trunks, these thorns are too large to protect against small herbivores

Facts:

• 19.2% representation in the 2021 inventory
• Native to central North America, with eastern Mass as some of the very reaches of it's range 
• They prefer moist, well drained soil
• Often planted in city parks and residential areas, especially the thornless Honeylocust variety, because of the shade it provides and resilience

Sources:

Honey Locust. (2024) Red-tail Land Conservatory. https://fortheland.org/honey-locust/ 

Honey Locust. (2024) The Morton Arboretum. https://mortonarb.org/plant-and-protect/trees-and-plants/honey-locust/#overview 

Littleleaf Linden

Image Source: Paul Radomski

Common Names: Littleleaf Linden, Little-Leaf Linden, Small Leaf Lime Tree, Small-leaved Lime

Species: Tilia cordata

Status: least concern, native to western Europe 

Characteristics:

• Grow to 50 to 70 feet in height, and 35 to 50 feet of spread
• Deciduous
• Gray Brown bark, smooth in young trees and grows ridged over time
• Leaves change from medium green in summer to clear yellow in fall
• Produce hanging, yellow flower clusters in summer

Facts:

• 16% representation in the 2021 inventory
• Provides attractive shade, and tolerates urban conditions well
• May be grown as a hedge, and tolerates heavy pruning
• Attract butterflies and bees

Sources:

Little-leaved linden. (2024) The Morton Arboretum. https://mortonarb.org/plant-and-protect/trees-and-plants/little-leaved-linden/#more-information 

Tila cordata. (2024) Missouri Botanical Garden. https://www.missouribotanicalgarden.org/PlantFinder/PlantFinderDetails.aspx?kempercode=a918 

Tila Cordata. (2024) North Carolina Extension Gardener Plant Toolbox. https://plants.ces.ncsu.edu/plants/tilia-cordata/

Norway Maple

Image Source: The Nature Conservatory via Yew York Invasive Species Information

Common Names:

Species:

Status: least concern, invasive, native to Europe and western Asia

Characteristics:

• Grow 40 to 50 feet high, and spread 35 to 50 feet
• Commonly confused with the Sugar Maple although the Norway Maple has large levees that turn yellow instead of the Sugars orange/red. Norway Maples are identified easier by a thick white sap while the Sugar Maple produces clear sap. The tips of leaves are also blunter than Sugar Maples.
• Produce helicopter like fruit with spreading wings
• Deciduous
• Produce small yellow flower clusters from April to May
• Tolerant of urban conditions for compacted soil, limited root space, and air pollution

Facts:

• 14.8% representation in the 2021 inventory
• First imported to the US in 1756 via seedlings from England for a private garden and nursery
• Norway Maples were planted after elm tree populations were damaged by Dutch Elm Disease in many cites
• The flying seeds of the Norway Maple assist in it's invasive spread
• The Norway Maple may release chemicals into the soil to prevent growth of other plants
• A combination of physical removal for young trees and repeated chemical control is suggested to manage

Sources:

Hunt, Evan. (2023) Invasive Species Spotlight: Norway Maple. Brandywine Conservatory. https://www.brandywine.org/conservancy/blog/invasive-species-spotlight-norway-maple 

Norway Maple. (2024) New York Invasive Species Information. https://nyis.info/species/norway-maple/ 

Norway Maple. (2024) The Morton Arboretum. https://mortonarb.org/plant-and-protect/trees-and-plants/norway-maple-not-recommended/ 

Red Maple

Image source: Paul Radomski

Common Names: Swamp Maple

Species: Acer rubrum

Status: not listed, native

Characteristics:

• Grow 40 to 60 ft tall and spread 35 to 45 feet
• Deciduous
• Red Maples can thrive in wetlands but prefer deep acidic soil. This versatility is in part because of a rood system that can adapt to wet or dry soil.
• Wet soil: short taproot and long lateral roots
• Dry soil: long taproot and short lateral roots
• Known for bright red coloring in fall, although Red Maples can have yellow and orange colorings
• winged fruit help to spread new trees

Facts:

• 9.1% representation in the 2021 inventory
• Red Maples can out compete other trees after wild fires because of their fast growth rate
• Moose, deer, and rabbits control Red Maple populations
• Red Maples are vulnerable to fungal rots and the maple leafhopper
• Red Maples can be used to make syrup

Sources:

Red Maple. (2024) The Morton Arboretum. https://mortonarb.org/plant-and-protect/trees-and-plants/red-maple/#care-knowledge

Red Maple. (2024) The National Wildlife Federation. https://www.nwf.org/Educational-Resources/Wildlife-Guide/Plants-and-Fungi/Red-Maple

Pin Oak

Image Source: Malkin, Julie https://www.wildflower.org/plants/result.php?id_plant=qupa2 

Common Names:

Species: Quercus palustris

Status: least concern, native

Characteristics:

• Grow to heights of 60 to 70 feet, and spreads 40 to 50 feet
• Fast growth rate
• Deciduous
• Produce small round acorns with a thin cap
• Deep green leaves with ridges and lobes
• Acorns sink in water, but still manage to be spread by streams and rivers
• Pin Oaks are are more common in southern and mid-western states, but reach into New England and MA. Pin Oaks in Main are considered introduced and beyond their natural range.

Facts:

• 8.8% representation in the 2021 inventory
• Often planted in residential areas and parks, only needing management during the first few years of growth
• Prefers wet, acidic soil
• Gypsy moths and grazing livestock can threaten Pin Oak saplings, and flooding can be deadly at any stage in life
• Oak wilt and oak blisters are potential vulnerabilities
• Chlorosis, yellowing of leaves, mean that Pin Oaks do better in acidic soils 

Sources:

Pin Oak. (2024) The Morton Arboretum. https://mortonarb.org/plant-and-protect/trees-and-plants/pin-oak/#overview

Quercus palustris — pin oak. (2024) Ivan L. Sander https://gobotany.nativeplanttrust.org/species/quercus/palustris/

The TWC Staff.  (2015) Quercus palustris. Lady Bird Johnson Wildflower Center. https://www.wildflower.org/plants/result.php?id_plant=qupa2

USDA NRCS New York State Office. (2002) Pin Oak. USDA Natural Resources Conservation Service. https://plants.usda.gov/DocumentLibrary/factsheet/pdf/fs_qupa2.pdf

Northern Red Oak

Image Source: Paul Radomski

Common Names:

Species:

Status:

Characteristics:

• Grow 60 to 75 feet, and spread 60 to 75 ft
• produce yellow gold flowers
• Bark is grey and covered in scaly ridges
• Leaves are dark green with 7 to 11 lobes, turn red in fall
• acorns take 2 years to develop and act as an important part of some indigenous diets

Facts:

• 8.2% representation in the 2021 inventory
• Slightly poisonous to humans, can cause stomach pains followed by constipation and diarrhea
• Attracts butterflies, moths, hummingbirds, and pollinators
• Prefer acidic, moist, well drained soil

Sources:

Sander, I. (1957) Northern Red Oak. USDA. https://www.srs.fs.usda.gov/pubs/misc/ag_654/volume_2/quercus/rubra.htm

Red Oak. (2024) The Morton Arboretum. https://mortonarb.org/plant-and-protect/trees-and-plants/northern-red-oak/#more-information 

Quercus rubra. (2024). North Carolina Extension Gardener Plant Toolbox. https://plants.ces.ncsu.edu/plants/quercus-rubra/ 

Japanese Zelkova

Image source: Morton Arboretum https://mortonarb.org/plant-and-protect/trees-and-plants/japanese-zelkova/

Common Names: Japanese Elm, Keyaki, Kaeki

Species: Zelkova serrata

Status: Near Threatened, native to Japan, Taiwan, and eastern China

Characteristics:

• Grow 50 to 80 ft, spread 50 to 75 ft
• Deciduous
• Leaves have alternating serrated edges
• Great at producing shade
• Vulnerable to damage from frost and cold conditions
• Smooth grey bark grows to be orange-brown as trees age

Facts:

• 6.6% representation in the 2021 inventory
• Tolerant of air pollution
• Resilient to Dutch Elm disease
• Japanese Zelkova are sometimes promoted as a replacement for the American elm

Sources:

Japanese zelkova. (2024) The Morton Arboretum. https://mortonarb.org/plant-and-protect/trees-and-plants/japanese-zelkova/

Zelkova serrata. (2024) Missouri Botanical Garden. https://www.missouribotanicalgarden.org/PlantFinder/PlantFinderDetails.aspx?kempercode=a927 

London Planetree

Image Source: Paul Radomski

Common Names: Maple leaved plane tree

Species: Platanus x acerifolia

Status: no status, non-native hybrid

Characteristics:

• Grow 70 to 100 ft tall and spread 65 to 80 feet
• light brown bark grows to be creamy olive colored
• Similar in appearance to the
  American sycamore but with deeper sinuses in leaves and the fruiting balls grow in pairs instead of singularly
• Female flower produces fuzzy bristly fruit balls 
• branching on leaves alternate, in contrast to maples whose leaves branch in mirrored opposites 

Facts:

• 6% representation in the 2021 inventory
• A hybrid of the American sycamore and Oriental plane that was first discovered in the 17th century
• London Planetree roots can lift sidewalks and entangle sewer pipes

Sources:

London Planetree (2024) Morton Arboretum. https://mortonarb.org/plant-and-protect/trees-and-plants/london-planetree/#more-information 

Bracewell, R. (2005) Platanus × hispanica. Trees of stanford. https://trees.stanford.edu/ENCYC/PLATace.htm 

Hedge Maple

Image Source: NC State Extension https://plants.ces.ncsu.edu/plants/acer-campestre/

Common Names: Field Maple

Species: Acer campestre

Status: native to Europe and Western Asia

Characteristics:

• Grow to 25 to 35 feet tall, and spread to 25 to 35 feet wide
• Lighter green leaves with three to five lobes, that turn yellow in the fall
• Deciduous
• Grow aggressively as hedges  when pruned which can block other plants, can quickly become invasive
• gray/black bark
• Produce winged fruit and milky sap

Facts:

• 5.9% representation in the 2021 inventory
• Attract birds, pollinators, and small mammals
• Easy to transplant because of shallow root systems

Sources:

Acer campestre. (2024) The North Caroline Extension Gardener Plant Toolbox. https://plants.ces.ncsu.edu/plants/acer-campestre/

Hedge Maple. (2024). The Morton Arboretum. https://mortonarb.org/plant-and-protect/trees-and-plants/hedge-maple-not-recommended/

Accolade Elm

Image Source: John Hagstrom, the Morton Arboretum https://mortonarb.org/plant-and-protect/trees-and-plants/accolade-elm/

Common Names: Morton elm

Species: Ulmus japonica x Ulmus wilsoniana

Status: hybrid, non-native

Characteristics:

• Grow 50 to 60 feet tall, spread 30 to 40 feet wide
• Glossy green leaves which yellow in the fall
• This is a hybrid produced by the Morton Arboretum in Illinois between Ulmus japonica and Ulmus wilsoniana for its resistance to Dutch Elm Disease
• Bark is gray and ridge
• Winged seeds

Facts:

• 5.5% representation in the 2021 inventory
• Thrive in moist, well drained soil

Sources:

ACCOLADE™ elm. (2024) The Morton Arboretum. https://mortonarb.org/plant-and-protect/trees-and-plants/accolade-elm/

Ulmus 'Morton' ACCOLADE. (2024) Missouri Botanical Garden. https://www.missouribotanicalgarden.org/PlantFinder/PlantFinderDetails.aspx?kempercode=d469

Lower Charles River Flood Plain and Alluvial Soils

With this update, I will examine the lower Charles River Watershed. I briefly touched on the upper and lower Charles River Watersheds in a previous post. The division between upper and lower is drawn at the Watertown dam. Below is a map by the EPA showing the division and boundaries.

Image Source: EPA

The lower Charles River Watershed is dominated by development and heavy human use as the potion of the watershed that contains parts of Boston proper. As you can see, almost the vast majority of the lower basin is actively used by people for residential, commercial, transportation, or recreational uses. There are small patches of marshes, reservoirs, smaller streams, and the river itself but the land is largely developed and impermeable.

Image Source: Image Source: Zarriello, P. J., & Barlow, L. K., 2002

The streams, river, and runoff do deposit sediment for the soil in the lower watershed, but much of the area especially towards the city is artificial fill and urban land (Weiskel, P. et al 2005). The artificial shaping of the land near the city is a longstanding tradition and began in the 1600s when the first European settlers began expanding the city by leveling some of it's famous hills to fill in the land between what was a peninsula and the mainland (Mitchell, J. H. 2008).

Image Source: Zarriello, P. J., & Barlow, L. K., 2002

Below, you can see a map of what the shoreline would look like before the deliberate filling of the bay. Many of the places I visit everyday would simply be water or marsh.

Image Source: Weiskel, P. et al 2005

It is hard to imagine these areas without human development, and like it or not the land has been changed. To improve how this land is used, the work I described in my Special Threats post around preventing Combined Sewage Overflows and strengthening both the infrastructure and preparation for flooding remains a priority. 

Mitchell, J. H. (2008). Paradise of All These Parts: A Natural History of Boston (1st ed.). Beacon Press. Weiskel, P. K., Barlow, L. K., & Smieszek, T. W. (2005). Water resources and the urban environment, lower Charles River Watershed, Massachusetts, 1630-2005. U.S. Department of the Interior, U.S. Geological Survey. Zarriello, P. J., & Barlow, L. K. (2002). Measured and simulated runoff to the lower Charles River, Massachusetts, October 1999-September 2000. U.S. Dept. of the Interior, U.S. Geological Survey. 

The fearsome Water Chestnut

The water Chestnut, or Trapa natans, is a invasive species to the northeast that first touched ground in the US within the Charles Watershed. Below you can find some information I have gathered on this species that overwhelms and smothers ponds, lakes, and streams beneath thick carpets of floating leaves.

Transparency Tube: Better than a Secchi disk?

Several years ago, I had experience as a volunteer and professional collecting water samples. As I started research for this post, I planned to focus on water sampling equipment and tests to make recommendations for an entry level water sampling kit. In that process however, I stumbled on a way to measure turbidity (how cloudy water is) that was new to me. In my days of water sampling, I always used a tool known as a Secchi disk but there is a cool tool called a transparency tube that is a better fit for many purposes.

Measuring the clarity of water is essential to understand how far light can penetrate for photosynthesis, animal visibility, and tracking the particles and nutrients in water.

Secchi Disk:

The Secchi disk is one of the simplest tools an enthusiast or scientist interested in water quality will use. It is made up of a rope attached to a weighted disk, usually colored white and black. To use a Secchi, you simply lower the disk into a body of water slowly until the disk is no longer visible, and then record the depth at which this happened by measuring the length of rope used when lowering. You can buy Secchi disks cheaply as scientific equipment goes, but they are also easy to construct if you want a project to start your first water sampling kit.

To show you how quick and easy taking a measurement with the Secchi Disk is, watch this video.

Video Source: AlaskaSeaGrant

Importantly, Secchi disks are best in bodies of water with deep, slow moving water because if the water is too shallow to reach a point where the disk is obscured or water is moving too quickly for the weighted disk to stay in place the Secchi will not give as accurate a reading of turbidity and water clarity. My experience water sampling was in a bay with slow moving water, both shallow and deep areas, and large variances in turbidity within a brackish estuary. In that environment the Secchi disk was perfect, and easy to train volunteers to use!

Transparency Tube:

The transparency tube is a tool that also measures the clarity of water and is relatively simple to use. In essence, a transparency tube is a transparent tube marked with measurement's along the side, with a valve as well as a miniature Secchi disk inside the base of the cylinder. More details can be found along with the diagram bellow at this link.

Image Source: J. Fetter and K. Koch, 2022

To use a transparency tube, you pour a water sample inside the tube and then slowly release water out the bottom valve until the mini Secchi disk becomes visible. You then record the turbidity according to the marks along the side of the tube at the point when the disk became visible. Transparency tubes normally use a measure called Nephelometric Turbidity Units or NTU. Importantly this scale is not linear and the area between 5 and 10 NTU will be much farther on a tube than 200 and 300 NTU for example. In contrast to Secchi disks, transparency tubes can be used in shallow water or swift flows.

Video Source: Washington Stormwater Center

If you purchase a transparency tube for your water sampling kit, be sure to store the tube with a covering that will prevent any scratches as the tube's transparency is required for accuracy. Likewise recorded the weather and light conditions when taking a measurement outdoors as those conditions can effect results. If the body of water you are interested in studying has slow moving, deep water I would recommend building your own Secchi disk before investing in a transparency tube for sheer simplicity, but these are a great option and provide accurate measurements of water clarity under conditions the Secchi performs poorly.

Special Threats!

With this post, I will highlight several threats to the Charles River Watershed. Most of these topics, I have touched on in previous posts but will expand on here.

Development:

The Charles River watershed runs through one of the biggest cities in the country, and millions rely on the water and services it provides. Around the Boston area, some areas have as much as 80% impervious ground cover creating problems for draining, pollution, runoff, and flooding (CRWA). The following picture is from a map of the impervious surfaces around Boston, This image is from 2005, and there has been almost 2 decades of development since then.

Image Source: Charles River Watershed Association

As mentioned in a previous post, there are 19 dams around the Chares River Watershed. Many of them are in states of disrepair and no longer provide benefit to the people that live here, while also actively harming local ecosystems. These dams have become a focus of ecological and indigenous rights pressure as activists try to get them removed. In the meantime, the local government just approved millions of dollars for repairs and maintenance of dams in 2024.

Water Quality:

The Charles has a bad reputation for it's water quality, even earning the nickname "that Dirty Water" by Standells song Dirty Water. Since 1995, there has been a deliberate push to monitor and improve the water quality of the Charles River with annual ratings from the EPA and work by government and community leaders to clean up that dirty water.

Below is a graphic created by the Charles River Watershed Association for the most recent EPA rating.

Image Source: Charles River Watershed Association

These grades represent how safe the Charles is for recreational use such as boating and swimming. It is only in recent years that swimming in the Charles is becoming a possibility, although swimming is still only allowed in specific areas and under specific conditions. 

A major issue for water quality is Combined Sewer Overflows (CSOs), that lead to sewage being washed into the river and harbor by rainwater. In 2023, 39 CSOs lead to 70 million gallons of stormwater mixed with untreated sewage into the river (Cut the Crap project). You may find an interactive map of CSOs in the Charles HERE. 

Image Source: Charles River Watershed Association

For a different Class, I made a slideshow about a threat to the Charles that I wanted to add here as well. Although I have shown on this blog that the water quality for the Charles has improved, just a few weeks ago we just had the first major cyanobacteria bloom in 4 years. Blooms are created by excessive nutrients released in the water by pollution and waste.

Flooding:

As a result of climate change, participation in the watershed has increased by 60% since 1958 and is expected to increase by up to 78% over the next 50 years (CRWA, 2024). The infrastructure we have is not well equipped to deal with that, but a collaboration between the local governments and community leaders across the watershed, the Charles River Climate Compact, has formed to prepare for and avoid the damage from extreme weather and flooding. This model is one of the compacts first actions and lets you examine the flooding by storms all the way into 2070.

Sources:

Gov. Healey Awards Nearly $14 Million in Funding for Dams and Coastal Infrastructure. (2024, September 26). Charles River Watershed Association. Charles River Watershed Association. https://www.crwa.org/river-current/gov-healey-awards-nearly-14-million-in-funding-for-dams-and-coastal-infrastructure

Cevasco, C. (2019, June 18). Damming Fish and Indians: Starvation and Dispossession in Colonial Massachusetts. The Junto. https://earlyamericanists.com/2019/06/18/damming-fish-and-indians-starvation-and-dispossession-in-colonial-massachusetts/

https://www.crwa.org/cutthecrap 

https://www.crwa.org/climate-compact 

Watershed Heroes Spotlight: the Choctawhatchee Basin Alliance!

The Choctawhatchee Basin Alliance (CBA) is my favorite environmental organization. 

I served two full service years in an AmeriCorps program that partnered with CBA, and was later hired by CBA to work with some of their education programs. They do incredible work for education, restoration, and research around the Choctawhatchee Bay and are great people. Below is a short presentation on the organization and some of what they do!

When the Charles Floods

 Historic Floods:

1938 - This year held a historic flood event for the Charles in the summer and then 2 months later the famous 1938 New England Hurricane caused a second wave of massive damage and flooding.

I found a local TV special about this hurricane where people who lived through the storm told the story decades later. I am from Florida and no stranger to hurricanes, but living through a storm like that without modern weather prediction or news technology to give warning is terrifying.

Documentary Source: NBC 10 WJAR 

1955 - Hurricanes Connie and Diane are two storms that came a week apart in August 1955. Both caused huge damage to New England. Diane left 20 inches of rain in two days and especially severe flooding.

Image Source: NOAA and National Weather Service

March 2010 - The most significant recent flood was in March of 2010 when a slow moving storm dropped up to 10 inches of rain over three days. 

Image Source: NOAA 

Future Flooding:

In my last post, I mentioned the work by the Charles River Watershed Association and the Charles River Climate Compact to make plans for the projected 78% increase in participation over 50 years from Climate Change. The following map is a model for what flooring for a 10 year storm could look like by the year 2070. The darker blue areas represent water levels 8 feet and above normal.

Image Source: Charles River Watershed Association

This map was created by the compact and is the first step for planning ways to mitigate the impacts of severe weather. You can find the Model HERE. I encourage anyone interested to take a look and model various storms. You are able to model past storms such as Hurricane Ida and map out public utilities and critical services.