Friday, October 11, 2013

Did You Know: What Brings Fall Colors to Our Trees?

by Ann Campbell, Jim Northrop, & Steve Reynolds

Fall colors on display at Bayne Park in Harding Township, NJ.
Like most other plants, trees rely on a biological process called photosynthesis to manufacture the nutrients they need to survive. Photosynthesis works by using light from the sun to convert carbon dioxide and water into the food compounds—sugars and other carbohydrates—necessary for growth and renewal. Since most of a tree’s photosynthesis takes place in the leaves, it is little wonder that those beautiful, ornately-veined structures have evolved to expose as much surface area as possible to incoming sunlight.

But what is it within each leaf that interacts with sunlight? And what is it we see in autumn when leaves turn from green to red or gold, purple or orange? The answer is pigment.

Trees leaves contain several pigments. All of them are important to the function of photosynthesis, but each one plays a slightly different role. Most of us already know about chlorophyll. It’s the green stuff found in plant cell bodies known as chloroplasts. Chlorophyll does all the heavy lifting of photosynthesis, and it’s the reason why leaves appear green to us for much of the year.

Yellow and brown shades from
carotenoid pigment dominate in these
fall maple leaves.
Less familiar may be the yellow, orange, and brown carotenoid pigments that leaves possess. Like chlorophyll, carotenoids are found inside the chloroplasts, and they absorb sunlight. But instead of using that light energy to produce food, they usually just pass it along to other part of the leaf. Carotenoids are very good at preventing damage from solar radiation. So, in a sense, they behave a lot like sunscreen for chlorophyll, which is a somewhat unstable compound and easily damaged by exposure to too much light.

Red, purple, and blue pigments known as anthrocyanins also feature in the composition of leaf tissue, although they accumulate outside of the chloroplasts in the sap. These compounds excel at absorbing high-energy light waves, especially those found in the blue-green and ultraviolet portions of the spectrum. This means that anthrocyanins are even better than the carotenoids at being “leaf sunscreen." It also means that they are found in greatest quantity when days are sunny and long.

All three pigments—chlorophyll, carotenoids, and anthrocyanins—are present inside of a leaf at any given time. Most trees would be hard pressed to survive, let alone mature and grow, if they entirely lacked any one of them. Still, this seems contrary to the human experience of autumn when the passing of one season into another is marked by a change in foliage color.

The truth is that autumn’s fireworks display—as well as the other, subtler color shifts one sees in leaves—has everything to do with how much of each pigments is present at any one moment. For instance, in early spring when new leaves are unfurling, concentrations of chlorophyll are still ramping up, while the carotenoids are already hard at work hard protecting tender new tissue from the sun. The result is a leaf that is lighter green, even yellowish, in hue.

As spring gives way summer, lush greens prevail in the forest. This is when trees are working overtime to produce and replace chlorophyll at an almost-alarming rate. They are so committed to overproducing the green stuff that all of the other colors gifted by carotenoids and anthrocyanins completely disappear. This is an important point to note. Those deep emerald hues of high summer not only reflect a tree’s need to synthesize food for growth and maturation, they also indicate a steady build-up and conservation of energy aimed at shepherding the rest of the tree through the harsh temperatures and low-light conditions of the impending winter. After all, there will be no leaves to create food in just a few short months.

Colors from anthrocyanin pigments predominate in these
leaves found along the Passaic River.
As autumn dances in, it is the duration of daylight—rather than falling temperatures—that prompts a tree to change its outfit. Even so, rainfall and thermal variations affect the variety of colors it will choose to show. Because carotenoids are always present, you can count on yellows, golds, and browns in fall forest foliage just about every year. But those gorgeous red and purple anthrocyanins will only erupt when sugar levels in leaf sap are quite high. For that to happen, most of the growing season will need to have supplied lots of sunny days and plenty of moisture.

A lot of environmental variables and a lot of chemistry go into producing the annual parade of color everyone has come to expect from our forests. That said, all bets are off if Mother Nature pitches a curve ball like an early frost or a few strong autumn storms. Heavy rains or unseasonable snow will knock senescent leaves from their branches. Freezing temperatures will stop the production of vibrant anthrocyanins dead in its tracks. Droughts too can stress trees, which, in turn, may prompt the shedding of leaves before any color develops at all.

What is the lesson then? Autumn passes quickly and it may not be so glorious next year. Enjoy the fall you have right now, and enjoy it while you can!

Tuesday, October 1, 2013

Cleanup Begins on the Lower Passaic: Summary and Opinion

Workers use a specialized environmental dredging bucket to
remove contaminated sediment from the RM 10.9 portion
of the Passaic River. Sediment is transported to a facility in
Kearny, NJ, for processing before it is moved by rail to a
landfill in Oklahoma. Courtesy of Lower Passaic River
Study Area Cooperating Parties Group.

In July, after many years of study and debate, the U.S. Environmental Protection Agency (EPA) began oversight of a $20 million dredge-and-cap project along the Lower Passaic River in Lyndhurst, New Jersey. The work will remove approximately 20,000 cubic yards of contaminated sediment from a short stretch of river adjacent to Riverside County Park. On August 7, GSWA Executive Director Sally Rubin attended a press conference intended to mark the start of dredging and introduce the project timeline to media representatives and the general public.

A long legacy of industrial pollution has rendered the Lower Passaic unswimmable, unfishable, and unlivable by most standards. In fact, in 1984, the overwhelming presence of hazardous substances in and below the water led the EPA to list 17 miles of the
river—from Dundee Dam near Garfield to Newark Bay—as part of the Diamond Alkali Superfund site.

The site takes its name from the now-defunct Diamond Shamrock Chemical Company (aka Diamond Alkali). As a major manufacturer of the chemical defoliant Agent Orange in the 1950s and 1960s, the corporation’s old Lister Avenue plant is now understood to be the predominant source of PCBs, dioxin, mercury, and other toxins afflicting the Lower Passaic.

For decades, cleanup of the contaminated river bottom has been mired down by innumerable feasibility and impact studies conducted by federal and state government agencies; as well as an unremitting, seven-year lawsuit. Filed by the New Jersey Department of Environmental Protection (NJDEP), the suit sought damages against 70 corporations deemed responsible for causing the pollution. Most of those corporations, including the oft-mentioned Occidental Chemical Corporation, are successors to the original Diamond Shamrock concern which was broken up, sold, and resold over the course of many years.

With the majority of impact studies concluded or wrapping up and the NJDEP lawsuit settled for $130 million in the state’s favor this past June, remediation is finally starting.

The project now underway at River Mile 10.9—RM 10.9 in common parlance—was not designed to address all 17 miles of the designated Superfund site. In truth, the intervention only covers a 5.6-acre area of severe contamination located offshore west of Riverside County Park. Nevertheless, Judith Enck, regional administrator for EPA Region 2, interprets activity at RM 10.9 as a positive sign of progress to come.

In a prepared statement released at the August 7 press conference Enck stated, “This cleanup removes some of the worst contamination in the Passaic River while the EPA continues to develop long-term cleanup plans for a 17-mile stretch of the Lower Passaic River...” An report from the same event portrayed the Administrator’s hopeful outlook: “When you clean up urban waterways, people flock to the river,” Enck said. “It’s a tremendous opportunity for recreation and economic growth.”

The Lower Passaic River Study Area Cooperating Parties Group (CPG) recently released a statement announcing a timeline for work at RM 10.9. Equipment barges were to move into the vicinity of Riverside Park by the end of July, and dredging was to be completed by the end of September. However, a number of drawbridge failures along the downstream river corridor delayed the initial staging. Assuming the project recovers lost time, site capping—which involves the placement of an engineered stone barrier over the area of sediment removal—will begin in October and will conclude by December 31.

A diagram depicting the arrangement of silt curtains around
the RM 10.9 site. The curtains will work to prevent loose
contaminated sediment from flowing downstream and
further polluting other area of the river. Courtesy of Lower
Passaic River Study Area Cooperating Parties Group.
Work will be conducted entirely on the water, and is not expected to adversely affect park access, or the health and safety of nearby homes and businesses. However, a number of measures have been implemented in order to ensure the continuing safety and security of workers and residents. Those measures include the presence of an onsite security officer, a roving team of noise monitors, air-quality monitoring stations, and the installation of a floating silt curtain system in waters surrounding the site. The silt curtain, which extends several hundred yards downstream, is designed to prevent disturbed sediments from washing into other areas.

New Jersey will cover the $20 million price tag associated with RM 10.9 by dipping into the $130 million fund secured by NJDEP’s lawsuit. Although all of that settlement money has been earmarked for cleanup of the Lower Passaic, the Christie Administration—in a bid to balance the state budget—is pushing to reallocate at least $40 million of it into the state’s General Fund.

Speaking at the August 7 press conference, NJDEP Commissioner Bob Martin explained that the substantial reallocation would be used to pay back the state for earlier environmental investigations and intervention planning his agency conducted on the Lower Passaic. According to The Observer Online, Martin clarified his position stating that, “Before EPA got involved, the state did a lot of research to understand the magnitude of the problem with the river…”

NJDEP’s argument in favor of retroactive remuneration to the General Fund does not sit well with many. Congressman Bill Pascrell from New Jersey’s 9th District is one of those opposed to the idea. In a letter to Governor Christie dated August 6, 2013, he wrote, “….it is essential that all funding recovered from the responsible parties be put toward the remediation and environmental restoration of the Passaic River, and not diverted to alternate programs.”

Congressman Pascrell’s view echoes those of others throughout New Jersey who see the governor’s move as a scheme to pad the state’s budget at the expense of Passaic River communities. From this perspective, a clear distinction is made between the fuzzy logic of collecting a reimbursement for past exploratory exercises, and the inevitable need to pay the bills coming due for current, effective, shovel-in-the-ground remediation projects. For those who have waited much of their lives to see even a single concrete step taken toward river restoration, there is nothing to contest. Funds from NJDEP’s settlement must be used to alleviate the present threat and real pain of Passaic River pollution, and not redistributed under the pretense of refunding the government for work that has already been bought and paid for.

The poet and author Maya Angelou famously wrote that, "When we cast our bread upon the waters, we can presume that someone downstream whose face we will never know will benefit from our action, as we who are downstream from another will profit from that grantor’s gift." The communities of the Great Swamp Watershed have put tremendous effort into ensuring that the water passing through their custody on its way to Newark Bay remains clean and accessible to all. It is a given that those efforts have not been entirely successful, neither have they been wholly altruistic. Nevertheless, the principle of Angelou’s statement stands. The Passaic River begins with fishable, swimmable, and livable water. There is no valid principle or reasoning available to deny or delay the same for those living beyond its headwaters.

As protectors and advocates for waters that eventually find their way into the Lower Passaic, the Great Swamp Watershed Association lauds the progress made with the initiation of the dredge-and-cap program at RM 10.9. We also encourage all parties involved to look forward, instead of dwelling on past travails. Maintain your established momentum and commit all available resources and earmarks to the continuation of viable, effectual environmental remediation and restoration. Action is the best and only way to stretch the gift of cleaner water from the Great Swamp all the way to Newark Bay. And the sooner it is done, the sooner all of us in New Jersey may profit from a swimmable, fishable, and livable Passaic River.