June 2014 – Conservation Sense and Nonsense

Mulberries: Red, white and goo

This is a guest post by Mark Spreyer, Director of the Stillman Nature Center in Barrington, Illinois. He can be reached at: stillmangho@gmail.com

We publish his article about mulberries as our July 4^th gift to our readers.

Thy stout heart

Now humble as the ripest mulberry

That will not hold the handling

–Coriolanus, Shakespeare

For those of us of a certain age, mulberries and childhood went hand in hand. Whether it was singing “Here we go round the mulberry bush” or reading Dr. Seuss’ And to Think That I Saw It On Mulberry Street, the word mulberry was all around us.

I was an adult before I learned that actual mulberry trees were all around us as well. We have two species, one red and one white, one native and one introduced. Both are wildlife favorites, and both grow here at Stillman. So, let’s take a walk down our local Mulberry Street.

Mulberry Leaves

White mulberry - Creative Commons Attribution 3.0 — The variously lobed red and white mulberry leaves look but don’t feel alike. White mulberry leaves are smoother to the touch than red mulberry leaves. Creative Commons Attribution 3.0

I have often had students, from elementary school to college, identify trees by looking at their leaves. Some have teeth, some have lobes, and some have neither.

Those that have lobes often have a set number. Sugar maple, for example, usually has five lobes.

Enter the mulberry. Whether red or white, mulberry leaves can be unlobed to variously lobed. No, they aren’t about to be limited by a set number!

Yet some tree books seem desperate to quantify the number of lobes. One source writes that mulberry leaves are “sometimes 2-lobed, sometimes 3-lobed, often unlobed….” Well, isn’t that helpful?

There is a pattern to the location of the different leaves. Multiple-lobed leaves are more likely to be found on young trees and root sprouts while unlobed leaves are found in the crowns of mulberry trees.

Red Mulberry (Morus rubra)

This is our indigenous mulberry. It ranges from southern Vermont down to southern Florida across to central Texas and back north to southeastern Minnesota.

In Illinois, red mulberries can be found growing in almost every county.

These trees prefer moist woodlands and deciduous bottomlands rubbing branches with American elm, hackberry, silver maple, and box elder.

Red mulberry is a medium-sized tree that can reach a height of fifty feet with a diameter of two feet. Its broad rounded crown makes red mulberry a useful shade tree.

Both red and white mulberry trees are named after the color of their fruit but be forewarned: when red mulberries are red, they are NOT ripe.

The tasty mulberries are ripe when they are purple-black, like a blackberry. When reaching for that first juicy handful, do remember that Shakespeare (as usual) was right. A ripest mulberry easily crumbles in your soon-to-be purple palm.

Not just humans enjoy a handful of sweet mulberries, but wildlife dines on mulberry street as well. A partial list of birds enjoying a midsummer meal of mulberries would include eastern kingbird, American robin, gray catbird, wood duck, starling, Baltimore oriole, northern cardinal, cedar waxwing, brown thrasher, plus red-bellied and red-headed woodpeckers.

Some mulberry munching mammals include opossum, raccoon, fox, skunk, an assortment of squirrels, plus a few dogs I know!

Simply put, red mulberry is one of the best summer fruit trees for wildlife.

White Mulberry (Morus alba)

Now that I think of it, it doesn’t matter to hungry animals if the berries are red or white. This brings us to white mulberry.

Like its red counterpart, white mulberry is a medium-sized tree with variously lobed leaves. It was introduced to N. America during colonial times (see below). It can now be found growing from Maine to Minnesota, south to Texas and east to Georgia. It also is naturalized across most of Illinois.

When white mulberries are ripe, they are indeed white or sometimes pink. The closer you look, though, the more confusing it gets since red and white mulberries freely hybridize. The resulting hybrid fruits come in a variety of colors between white and purple.

White mulberries will grow in almost any upland habitat being particularly at home in urban environs.

Silk Road to Mulberry St.

If you break the leafstalk of a white mulberry, milky sap exudes. This Elmer’s goo is the foundation of a multi-cultural exchange that dates back thousands of years.

Take white mulberry leaves and add the domesticated Chinese silkworm caterpillar (Bombyx mori) and the result are large cocoons spun of the finest silk.

Unwrap that silk and one can weave it into garments that were desired by traders around the world.

What comes next? The ancient and famed silk road (trade routes actually) that crossed Asia from China to Europe.

Others thought there might be an easier way to get their silk. After it was discovered that imported silkworm caterpillars found native red mulberry leaves to be too tough, tens of thousands of white mulberries were being raised by nurserymen in colonial Virginia.

Some of those who planted these promising saplings were Ben Franklin, George Washington, and Thomas Jefferson.

While a few American entrepreneurs succeeded in this labor-intensive silk business, the growing textile industries soon found ways to make quicker profits.

The neglected white mulberry trees fed birds and mammals that, in turn, spread white mulberry seeds around a good chunk of the continent.

Back on Mulberry Feet

Mulberries are indeed good street trees. Once established, they can withstand salt, drought, air pollution, and soil compaction. Some will say, there is little need to plant mulberries as wild animals are doing a fine job at that.

However, when the berries fall thick from the trees they can make you feel like you have double-sided tape on the soles of your shoes. Your gooey shoes pick up bits of gravel and so it goes.

Keep in mind that mulberries are dioecious meaning there have separate male and female plants. Planted male mulberries, of course, won’t bear fruit.

With apologies to Dr. Seuss– perhaps you like sticky feets or just want handfuls for eats, either way visit Stillman for treats along our Mulberry Streets.

Mulberry Jam Recipe

Mr. Spreyer’s note: This recipe comes from the Illinois Department of Natural Resources. In particular, the cooking credit belongs to Deb Singer and Kathy Andrews.

I expect that red mulberries are used more often than white mulberries in this recipe.

I say this because I think we are used to ripe berries being red or darker in color (i.e. blackberries, blueberries, strawberries, raspberries). However, I bet if you hybridize your jam with some white mulberries, it would taste just as good.

Oh yes, a mulberry pie would also be a nice summer treat.

3 cups crushed mulberries

½ cup lemon juice

1 package (1.75 ounces) powdered pectin

6 Cups sugar

Bring berries, lemon juice and pectin to a rolling boil. Add sugar. Return

to a boil and boil for 1 minute. Skim off foam. Ladle into prepared jars and process in a water bath for 10 minutes

HAPPY FOURTH OF JULY!

Climate Change vs. Biodiversity: NOT!!

A new study reported changing public and scientific interest in biodiversity compared to climate change. Using reports in the media and scientific journals in the United Kingdom and the US, as well as funding of scientific studies by the World Bank and the National Science Foundation, the study reports that the interest in climate change has increased and the interest in biodiversity has decreased in the past 25 years.

This analytical approach seems to suggest that these two environmental issues are mutually exclusive, that the interest in one is at the expense of the other. We find this both unfortunate and unnecessary because we consider these two issues intimately related. Climate change is increasingly the biggest threat to biodiversity. If plants and animals are unable to adapt to climate change, they are doomed to extinction.

Therefore, we believe that science should study these topics together. In fact, the study on which we are reporting acknowledges the relationship between these topics: “Dual-focus projects are being funded more often, but… ‘this is relatively small and does not mitigate the plateauing expenditure on biodiversity research.’” (1)

Conservation in a changed climate

As long as conservation and “restoration” projects are devoted to replicating historic landscapes, they are likely to be unsuccessful. The climate, atmosphere, and soil conditions are no longer suited to a landscape that existed hundreds of years ago, particularly in urban environments. Therefore, if biodiversity is to be preserved by conservation and restoration, such projects must look forward, not backwards.

We have been watching the Nature Conservancy closely for signs that it is adapting to climate change. We look to the Nature Conservancy to lead the way because they employ hundreds of scientists. In contrast, many mainstream environmental organizations employ more lawyers than scientists.

We have reported that the Conservancy’s Chief Scientist, Peter Kareiva, is at least paying lip service to an approach to conservation that takes into consideration the profound changes in the environment caused by the activities of man. This acknowledgement of the irreparably altered environment is encapsulated by the proposal to name a new geologic era, the Anthropocene.

Unfortunately, the old guard of conservation biology has engaged in a vigorous campaign to silence the Conservancy’s new approach. This conflict between the old guard and scientists who have proposed a more realistic approach to conservation was recently reported by the New Yorker. (2) According to that article, Peter Kareiva has made a commitment to the old guard to quit publishing anything regarding the Anthropocene and its implications for conservation practices.

The Nature Conservancy has responded to the article in the New Yorker in its on-line blog. It doesn’t explicitly address the question of whether or not a commitment has been made to quit advocating for a more realistic approach to conservation. However, it implies that the Conservancy plans to continue on a course of scientific innovation and experimentation, which it describes as “practical.” Here is a specific choice made by the Conservancy that typifies this approach:

Monarch butterflies roosting in eucalyptus tree.

“We know it was worth spending millions of dollars to rid Santa Cruz Island of non-native pigs. But we are pretty sure it would not be worth spending what could be hundreds of millions of dollars to rid California of non-native Eucalyptus trees (which also happen to harbor wildlife and monarch butterflies.)” (3)

Although the Nature Conservancy’s Chief Scientist may have agreed to “shut up,” we see signs of the Conservancy’s new approach in its latest magazine. In a brief article entitled “Forests of the Future,” the magazine reports that they are no longer planting the species of trees that existed in the past in one of their properties in Minnesota, because they don’t believe that species is adapted to current or predicted future conditions. Instead they are actively engaged in reforestation of the land with new species:

“Over the past two springs, the team planted 88,000 tree seedlings across 2,000 acres in the northeastern corner of the state. The seedlings consisted of species that should survive better in a warmer and drier climate—trees, such as red oak, found in higher numbers just south of the area. For a team accustomed to restoring forests to match historical landscapes, helping the North Woods [of Minnesota] adapt to a predicted future climate is a new but necessary idea. [The Conservancy’s science director in Minnesota] says, ‘All of our modeling is saying the same thing,’ she adds, ‘We needed someone to actually go out and start trying some of this stuff.’” (4)

Looking forward not back

We are very encouraged by the Conservancy’s new approach and we hope that other land managers will be inspired by it. We are also reminded of a recent visit to a nature reserve near San Luis Obispo managed by the local chapter of the Audubon Society. We reported about this reserve in a recent article because the land managers had planned to destroy all eucalyptus trees on that property but were forced to scale back their plans in response to a noisy negative reaction from the public.

Dying oak tree, Sweet Springs Nature Reserve

On our recent visit, we learned that this was a wise choice because many of the oak trees that were planted on this reserve by those who wish to “restore” it are quite dead despite the fact that the reserve has an extensive irrigation system. These land managers looked back and the result of that retrospective thinking is a landscape of dead native trees.

Irrigated native plant garden, Sweet Springs Nature Reserve

Climate change requires land managers to wake up to the realities of what will grow where. Land managers in the San Francisco Bay Area appear to be blind to that reality. They repeatedly plant species where they grew hundreds of years ago and we are forced to watch the plants die repeatedly.

(1) “Climate change beats biodiversity as a press, scientific, and funding priority,” Science Daily, June 11, 2014

(2) D.T. Max, “Green is Good,” New Yorker, May 12, 2014

(3) Mark Tercek and Peter Kareiva, “Green is Good: Science-Based Conservation in the 21st Century,” May 5, 2014

(4) “Forests of the Future,” Nature Conservancy, June/July 2014

Ants used to scapegoat our urban forest

Ants are important members of the ecosystem. They improve the fertility and consistency of the soil. They distribute plant seeds. They are both predators of and food for other insects as well as birds and omnivorous mammals. Therefore, their abundance in an ecosystem is often considered an indicator of its health.

Today we will report on a study of ant populations in San Francisco’s “natural areas,” parks that were designated over 15 years ago for restoration and preservation of native plants. This study reaches this conclusion:

“The results of this study indicate that natural areas within urban parks play a critical role in supporting ant biodiversity. Many habitats in the natural areas of San Francisco’s parks support healthy, diverse ant communities. Areas of non-native forest, however, reduce this diversity. Maintaining open grasslands, reducing tracts of non-native forest, removing the invasive understory, and thinning forest canopy may all help support a healthier ant community and ecologically valuable parks.” (emphasis added) (1)

Could this ant study be the first example we have found of evidence that native plants benefit wildlife and conversely that our non-native urban forest is less valuable for wildlife? We have examined this study to determine how it reached this conclusion. We have compared this study to similar studies that report different findings. We reached the conclusion that this study does not support its conclusion that “reducing tracts of non-native forest…may…help support a healthier ant community and ecologically valuable parks.”

The relationship between ant communities and soil moisture

The ant study used pitfall traps to survey the abundance and diversity of ant populations in 24 “natural areas.” It also measured the moisture of the soil in proximity of the traps. The ant study found that soil moisture and ant abundance and diversity were positively correlated at low levels of moisture, but that high levels of moisture found in eucalyptus forest were negatively correlated with abundance and diversity of ants:

We will tell you how this ant study used this empirical observation of the relationship between soil moisture and ant populations to reach its conclusion that non-native forests must be “reduced” to achieve “ecologically valuable parks.”

Generalizing about “urban forests”

This study of San Francisco’s ant population asks us to believe that its negative assessment of San Francisco’s urban forest applies to all urban forests: “Urban forests are structurally different than natural forests. Besides being smaller, fragmented, and more isolated than non-urban forests, urban forests also show increased canopy cover, greater disturbances due to human traffic and pollution, and differences in leaf litter accumulation.” (1)

We don’t think it is possible to generalize about all urban forests. Here are two sources which suggest that the ant study has over-generalized about urban forests and ants found in them:

According to the US Forest Service survey of urban forests, San Francisco has one of the smallest tree canopies in the country. Only 11.9% of San Francisco is covered by the tree canopy, compared to 20.9% of New York City. According to that survey, San Francisco’s urban forest removes 141 tons of pollutants per year compared to 1,677 tons of pollutants removed by New York City’s urban forest.
Ants are found in some urban forests. A study in Toledo, Ohio and Detroit, Michigan compared ant populations in urban habitats (forests in city parks, community gardens, and vacant lots). (2) The study found greater diversity of ant species in forests than in other habitat types, but fewer ants. They found 26 species of ants in the forest, 20 in vacant lots, and 14 in gardens. They found no correlation between various characteristics of vegetation and ant diversity or abundance. Soil moisture was not measured by this study. Generalizations about urban forests derived from one study in San Francisco clearly do not apply to Toledo and Detroit.

More soil moisture in forest with a closed canopy

The ant study in San Francisco predicts greater soil moisture in a forest with a closed canopy and dense understory:

“A combination of high soil moisture, dense canopy cover, and dense understory (habitat complexity) may help explain the lack of ground-foraging ants in urban forests.” (1) The study associates those characteristics specifically with the eucalyptus forest: “Within forest types examined, eucalyptus forests contained significantly more soil moisture than other forest types and also had lower ant richness and abundance.” (1)

We don’t think these generalizations can be applied neither to all eucalyptus forests nor solely to eucalyptus forests:

The density of eucalyptus forest in the San Francisco Bay Area varies widely according to data presented recently by Professor Joe McBride to the Commonwealth Club:

Location	Average Number of Trees per Acre
Presidio, San Francisco	163
Land’s End, San Francisco	364
Tilden Park, Berkeley	540
East Ft Baker, Marin County	1795

In other words, not all eucalyptus forests have closed canopies.

The density of understory in the eucalyptus forests of the Bay Area also varies widely. One of the densest understories exists on Mount Sutro, which is the location of the Interior Greenbelt, where the ant study reports finding no ants. In drier locations, such as Bayview Hill, there is little understory in the eucalyptus forest, which may be why the ant study reports finding ants there. Bayview Hill is on the east side of San Francisco and therefore receives much less fog than Mount Sutro, which is closer to the ocean.
Eucalyptus forest is not unique in often having a closed canopy. Native redwood forest also has a closed canopy: “Many meters above the ground, the branches of trees, especially those of redwood, merge to form a ceiling, or canopy.” (3)

Fog and soil moisture

The ant study describes the relationship between fog and soil moisture in San Francisco: “The increased moisture in eucalyptus is due to the fact that summer fog tends to condense on eucalyptus leaves and branches and drip down to the soil below. Such fog drip can add as much as 42 cm of water to eucalyptus forest during a single summer.” (1)

Fog in San Francisco is unrelated to the fact that its forest is predominantly eucalyptus:

Redwood forest. NPS

Although redwoods did not live in San Francisco when Europeans arrived in 1769, they lived there in the distant past. Native redwoods now exist only on the coastal fog belt of California. Fog is essential to their survival: “During the study period, 34%, on average, of the annual hydrologic input was from fog drip off the redwood trees themselves. When trees were absent, the average annual input from fog was only 17%, demonstrating that trees significantly influence the magnitude of fog water input to the ecosystem…The results presented suggest that fog, as a meteorological fact, plays an important role in the water relations of the plants and the hydrology of the forest.” (4)
Fog exists along the northern coast of California because the interior is hot and the ocean is cool. When the cool ocean air meets the hot air from the interior, fog forms. The existence of fog has nothing to do with the species composition of the forest. Any tall tree is capable of condensing the fog, which then drips to the forest floor, providing water to both the trees and their understory. The eucalyptus forest is not to blame for this sequence of events.

The nativity of the urban forest is irrelevant to the ants

The ant study implies that there are few ants in San Francisco’s urban forest because the forest is not native to San Francisco: “…reducing tracts of non-native forest…may all help support a healthier ant community and ecologically valuable parks.”

Soil moisture is the operative variable in predicting abundance and diversity of ant populations. The nativity of the vegetation is irrelevant to the ants:

If the urban forest in San Francisco was native redwoods, it would precipitate equal amounts of fog, resulting in equal amounts soil moisture. The ant population would probably be similar.
A study of ant populations in the central Appalachian Mountains found the same relationship between soil moisture and ant populations in native forests: “Fewer ants, lower number of species, and lower ant diversity were found at sites with higher elevation and soil moisture.” (5)
A study of ant populations in Northern California grasslands found that the characteristics of the soil were better predicators of ant populations than the types of vegetation: “Plants were less important than soil attributes in explaining variation in overall ant species richness and abundance…” (6) Chemical composition and consistency (sand vs. clay) of soils were evaluated by this study, but not soil moisture

“Science” in the service of nativism

We consider this ant study a classic demonstration of nativism. In this case, soil moisture was confounded with the non-nativity of forest in San Francisco. The nativity of San Francisco’s forest is irrelevant to the amount of soil moisture. Any closed canopy forest of tall trees would precipitate equal amounts of fog and have a similar impact on ant populations.

The study speculates that the allelopathic properties of eucalyptus may have a negative impact on the ants, but offers no evidence. We have found no evidence of allelopathic properties of eucalyptus. Nor do we think that the existence of ants should be the sole criterion for “ecological health.” Would we demand the destruction of redwood forests so that we could have more ants? We doubt it.

However, we must also give credit where credit is due. The ant study reports that the existence of the non-native Argentine ant does not have a negative impact on the populations of native ants. They report that the Argentine ants occupy the perimeter of the “natural areas” where native ants generally are not found. This is a refreshing departure from the usual nativist claims that all non-native plant and animal species have negative impacts on native species.

(1) Kevin M. Clarke, et. al., “The influence of urban park characteristics on ant communities,” Urban Ecosyst, 11:317-334, 2008

(2) Shinsuke Uno, et. al., ”Diversity, abundance, and species composition of ants in urban green spaces,” Urban Ecosyst, 13:425-441, 2010

(3) UC Berkeley Botanical Garden, “Plants and Their Environments”

(4) T.E. Dawson, “Fog in the California redwood forest: ecosystem inputs and use by plants,” Oecologia, 117-4:476-485, December 1998

(5) Changlu Wang, et. al., “Association Between Ants and Habitat Characteristics in Oak-Dominated Mixed Forests,” Environmental Entomology, October 2001

(6) April Boulton, et. al., “Species Richness, Abundance, and Composition of Ground-Dwelling Ants in Northern California Grasslands: Role of Plants, Soil, and Grazing,” Environmental Entomology, February 2005

“Restoring” vegetation does not restore an ecosystem

One of the persistent questions in our interminable debate with native plant advocates is whether or not native vegetation provides superior habitat for wildlife compared to existing non-native vegetation. At the heart of that question is the closely related question of whether or not more insects are found in native vegetation than in non-native vegetation. That’s because insects (and other arthropods) are near the bottom of the food web. If there are fewer insects, there are probably fewer birds and other animals that eat insects. We have told our readers about many studies that find equal abundance and diversity of insects in native compared to non-native vegetation, so we won’t repeat them, but here’s a brief list of those studies and links to them for new readers:

Does “restoration” of native vegetation increase insect populations?

Arthropods - Creative Commons Share Alike — Arthropods – Creative Commons Share Alike

In this post we will consider this issue from a slightly different angle: can insect population or diversity be increased by “restoration” of native vegetation? Even if we accept the premise of native plant advocates that native vegetation supports greater abundance and diversity of insects, can that population be “restored” by eradicating non-native vegetation and replacing it with native vegetation? That question is answered with a resounding “NO” by a study that compared arthropod abundance and diversity in undisturbed (predominantly native vegetation), disturbed (predominantly non-native vegetation), and disturbed sites 5 and 15 years after restoration. (1) Restoration methods described in the study are mowing followed by disking and seeding, disking and seeding, planting of container stock, and clearance by hand. All sites were irrigated initially. No mention is made of herbicide use or prescribed burns to eradicate non-native vegetation. The vegetation type in all 15 sites in Southern California was coastal sage scrub. This is the dominant vegetation type along the coast of California and is the goal of many restoration projects in the San Francisco Bay Area. Many species of both native and non-native vegetation in the study sites also exist in the Bay Area.

Coastal sage scrub in Southern California - Creative Commons Share Alike — Coastal sage scrub in Southern California – Creative Commons Share Alike

The study used pitfall traps to collect arthropods in these sites. Arthropods are invertebrates that include insects, arachnids (spiders), and crustaceans (aquatic species not relevant to this study). Arthropods are further divided into guilds such as herbivores, predators, scavengers, and parasites. Because of the method of collecting in pitfall traps, few herbivores were found. Here are some of the findings of this study:

“Arthropod diversity at undisturbed and disturbed sites was greater than at sites that were 5 and 15 years following restoration.”
“Number of arthropod species was not significantly different among undisturbed, disturbed, and restored sites.”
“Vegetation at disturbed and undisturbed sites differed significantly; older restorations did not differ significantly from undisturbed in diversity, percent cover, or structural complexity.”
“Vegetation characteristics did not differ significantly between the newly restored site and disturbed sites.”
“…arthropod communities at all restored sites were, as a group, significantly different from both disturbed and undisturbed sites.”
“As found in other studies of other restoration sites, arthropod communities are less diverse and have altered guild structure.”

Here is the concluding discussion of this study:

“Of the restoration sites sampled, none had developed an arthropod community that resembled undisturbed or disturbed native coastal sage scrub. Restoration sites in general exhibited lower arthropod diversity and a preponderance of exotic arthropod species. The time elapsed since revegetation effort had no discernible effect on arthropod community structure; there was no gradual return of the community to a more natural structure over time”.

“Restorations” do not improve arthropod abundance or diversity

This study found that arthropod population and diversity was the same in disturbed (non-native) and undisturbed (native) vegetation. When disturbed vegetation was “restored” arthropod population was maintained but the composition of the arthropod community was significantly changed even 15 years after the restoration was completed. There were more “exotic” species of arthropods in the restored sites even though the vegetation was similar to the undisturbed sites of native vegetation. The restored vegetation was native, but its arthropod occupants weren’t.

However, the birds and other animals that prey on those insects don’t care if the insects are native or non-native. Much like humans, animals are not concerned with the nativity of their food. The non-native apple you are eating is just as tasty whether you are eating it in its native range in Central Asia or where it has been introduced. If you have an apple tree, you know the birds and squirrels enjoy the apples too and the bees and other pollinators enjoy the apple blossoms. Most of what we eat is not native, yet many people are obsessed with the nativity of vegetation, claiming that animals require native vegetation even though humans don’t.

An important caveat

The predominant vegetation type in the San Francisco Bay Area is coastal scrub, which is also the vegetation type in the study of arthropod populations. This suggests that if a similar study were conducted here, the results might be similar. However, there is one very important difference between the restorations studied in Southern California and the restorations in the Bay Area. Land managers in the San Francisco Bay Area are using large amounts of herbicides to destroy non-native vegetation. The study in Southern California reports no herbicide use in restoration sites. It seems likely that herbicides sprayed in restoration projects in the Bay Area would decrease the population of arthropods. We would like to see a study that tests that hypothesis.

There is more to an ecosystem than plants

The veneration of native plants has become a national obsession. Demands for eradication of non-native plants are supported by many fictions to justify these destructive projects. One of those fictions is that wildlife requires native vegetation. We have found no empirical evidence to support that assumption. The study we are reporting today is yet more evidence that restoring native plants does not restore an ecosystem. In this case, after 15 years of effort, land managers were eventually successful in establishing a population of native plants. However, these “restored” native landscapes did not support a population of insects and spiders that were comparable to either the undisturbed native landscape or the unrestored non-native landscape. We have been looking for some legitimate reason to engage in these destructive projects for over 15 years. We have yet to find any justification for spraying our public lands with herbicides or destroying hundreds of thousands of healthy trees. We will keep looking.

(1) Travis Longcore, “Terrestrial Arthropods as Indicators of Ecological Restoration Success in Coastal Sage Scrub (California, USA),” Restoration Ecology, December 2003, Vol. 11 No 4, pp.397-409

Spartina eradication: Herbicides are their dirty little secret

This is a good news/bad news story about the eradication of non-native Spartina marsh grass and the impact it has had on the population of endangered California Clapper Rail:

Spartina alterniflora, Smooth Cordgrass. USDA photo

The good news: US Fish & Wildlife has temporarily halted efforts to eradicate non-native Spartina (Spartina alterniflora) in the San Francisco Bay Area because the population of endangered California Clapper Rail has declined by 50% during the period of eradication efforts from 2005 to 2011. (1) This problem was identified several years ago and was attributed to the lack of cover for the rail as a result of eradication of non-native Spartina, which grows more densely, taller, and doesn’t die back in winter as the native Spartina does. (2)
The bad news: US Fish & Wildlife attributes this negative impact on the Clapper Rail population on the slow recovery of native Spartina (Spartina foliosa).
Spartina foliosa – USFWS

They do not acknowledge that non-native Spartina provides superior cover compared to the native species. Nor do they acknowledge that non-native Spartina was killed with herbicides. Therefore, they do not consider the possibility that the slow recovery of native Spartina may be attributable to the herbicides that were used to kill the non-native plant. They also continue to claim that the recovery of the endangered California Clapper Rail depends upon the return of native Spartina, despite the overwhelming evidence to the contrary. The California Clapper Rail is a sub-species of Clapper Rail; the Clapper Rail is abundant on the East and Gulf Coasts and not endangered perhaps because of the superior cover provided by Spartina alterniflora on those coasts. (3) Based on these fictions, US Fish & Wildlife proposes a new strategy that will simultaneously eradicate non-native Spartina while intensively planting native Spartina. (1)

We have been following the Spartina eradication project since 2011. For the benefit of new readers, we will review the issues with a few excerpts from previous posts on Million Trees.

Spartina alterniflora: Treasured on the East Coast, reviled on the West Coast

Spartina alterniflora (Smooth Cordgrass) is a species of marsh grass native to the Atlantic and Gulf coasts of the United States, where it is considered a valuable plant making important contributions to the coastal ecology:

Its dense growth provides protection against storm surge and “erosion control along shorelines, canal banks, levees, and other areas of soil-water interface.” (4)
It filters nutrients, sediments and toxins from the water that flows off the land before reaching the ocean, acting as a natural water treatment facility.
It provides cover and food for birds, mammals and marine animals that live in the coastal marsh.

Where Smooth Cordgrass has died back in its native range, the dieback has been considered a serious environmental threat:

In 2001 the Governor of Louisiana declared a “state of emergency” when Smooth Cordgrass declined and the state obtained $3 million of federal funding to study and hopefully reverse the decline. This study resulted in the development of a method of aerial seeding of Smooth Cordgrass to restore declining areas of marshland. (5)
A similar, but smaller dieback of Smooth Cordgrass in Georgia led to a collaborative research and on-going monitoring effort by 6 research institutions in Georgia.
Similar dieback of Smooth Cordgrass has been reported as far north as the coast of Maine. A researcher at the Connecticut Agricultural Experiment Station is quoted in that report as saying, “In New Orleans, if their marshes were intact, the storm surge of Katrina would not have reached the levees.” (6)

The war on Smooth Cordgrass on the West Coast

Smooth Cordgrass is not native on the Pacific Coast of the United States. Therefore it is treated as an alien invader to be eradicated with herbicides:

$24 million was spent to eradicate Smooth Cordgrass in San Francisco Bay and Willapa Bay from 2000 to 2010 (7)
$16.3 million is projected to be spent on the entire West Coast from 2011 to 2020 (7)

Spartina is being eradicated with an herbicide, imazapyr. This is a new herbicide about which little is known. The analysis that was done to justify its use in the Spartina eradication project admits that no studies have been done on its effect on shorebirds, including the endangered Clapper Rail.

The Material Safety Data Sheet mandated by the Environmental Protection Agency tells us that imazapyr is “not readily biodegradable.” So, in the event that we eventually learn that this herbicide is harmful to shorebirds and/or to us, we probably should assume that it will still be in the environment in the nearly 200 sites in the San Francisco Estuary on which it has been sprayed. Imazapyr is also being sprayed–sometimes from helicopters–in hundreds of places along the West Coast, including Oregon and Washington.

Imazapyr is often mixed with glyphosate by the Spartina eradication project. Glyphosate is a non-selective herbicide. That is, it kills any plant it is sprayed on at the right stage of its growth. But imazapyr is far more insidious as a killer of plants because it is known to travel from the roots of the plant that has been sprayed to the roots of other plants. For that reason, the manufacturer cautions the user NOT to spray near the roots of any plant you don’t want to kill. For example, the manufacturer says explicitly that imazapyr should not be sprayed under trees, because that tree is likely to be killed, whether or not that was the intention.

Furthermore, no tests have been conducted on the toxicity of combining multiple pesticides in a single application. Therefore, we know nothing about the possible synergistic effects of combining imazapyr and glyphosate.

These facts about the herbicides used to eradicate non-native Spartina bear repeating. The main herbicide being used is known to be mobile in the soil and persistent in the environment. The herbicide with which it is often mixed is an indiscriminate killer of any plant on which it is sprayed. Therefore, the likelihood that these herbicides will prevent the establishment of the new plantings of native Spartina should be taken into consideration. The entire enterprise seems deeply flawed, both harmful and futile.

Bringing it home to the Bay Area

So, what does this have to do with you? If you are concerned about pesticide use, you might be interested in the fact the East Bay Regional Park District (EBRPD) used 203 gallons of imazapyr in 2009 and 121 gallons in 2010 for the sole purpose of eradicating Spartina on their properties. We don’t know how much imazapyr EBRPD used in 2011, 2012 and 2013, because they haven’t published a report of pesticide use since 2010. Since their properties are only on the east side of the San Francisco Bay, we should assume that at least that much imazapyr was used by land managers on the west side of the Bay.

Displacement of Clapper Rails in San Francisco

California Clapper Rail. British Wikipedia

In July 2011, a Clapper Rail was seen and photographed at Heron’s Head in southeastern San Francisco. There was quite a bit of excitement about this sighting because a Clapper Rail had not been seen in San Francisco for decades. That excitement dissipated when we learned more about where this bird came from, which provided a probable reason for its arrival.

The Clapper Rail was wearing a radio collar that had been put on him and 109 other rails by the USGS to track their movements. He had moved from Colma Creek, 11 km south of Heron’s Head, which is one of nearly 200 Spartina “control sites” in the San Francisco Estuary. The bird sighted at Heron’s Head is one of three Clapper Rails that have left Colma Creek since 2007, when the radio collars were placed. The Spartina control project has been going on for over 10 years, so we have no way of knowing how many Clapper Rails were displaced prior to 2007. In 2012, non-native Spartina at Heron’s Head was sprayed with herbicides. Where did the Clapper Rails go from there? Was there anywhere left for them to hide?

Pesticide Application Notice, Heron's Head, 2012 — Pesticide Application Notice, Heron’s Head, 2012

As our readers know, native plant advocates claim their “restoration” projects benefit wildlife. They can offer no evidence for this claim. But there is considerable evidence that proves them wrong. The endangered California Clapper Rail is one such case.

(1) Adam Lambert et.al., “Optimal approaches for balancing invasive species eradication and endangered species management,” Science, May 30, 2014, vol. 344 Issue 6187

(2) “West Coast Governors’ Agreement on Ocean Health, Spartina Eradication Action Coordination Team Work Plan,” Released May 2010, page 12

(3) Cornell Ornithology Lab: http://www.allaboutbirds.org/guide/clapper_rail/id

(4) “Smooth Cordgrass,” USDA/NRCS Plant Fact Sheet.

(5) Dorset Hurley, “Geogia’s Marsh Die Back and Louisiana’s Marsh Browning,” Altamaha Riverkeeper

(6) “What’s killing off our salt marshes,” Going Coastal Magazine, September 15, 2008

(7) “West Coast Governor’s Agreement on Ocean Health,” May 2010, page 5-6