Keystone Species: How Predators Create Abundance and Stability

Wolves, bears, otters, starfish — these ecosystem engineers affect nature in overt yet surprisingly subtle ways.

Posted for June/July 2011, by Douglas H. Chadwick, Mother Earth News, motherearthnews.com

Long reviled as beasts of waste and desolation, wolves — along with other keystone predators — actually bring ecological stability to the habitats in which they live.

The day came clouded and wind-tossed, with 5 inches of fresh snow in the valley and a lot more piling up overhead on the peaks. It was early December in Montana in Glacier National Park. Although winter wouldn’t officially start for another two weeks, blizzards and bitterly cold temperatures had long since sent the bears into their dens.

But not every bear.

Very large, very fresh paw prints on the trail in front of me said at least one grizzly wasn’t ready to call it quits for the year.

Sleeping in underground dens keeps bears safe and insulated through the snow-smothered months while they live off reserves of fat. The biggest and most powerful ones — adult male grizzlies — sometimes leave their hidden chambers to roam about during midwinter thaws. Before, few naturalists realized these heavy-bodied bears could stay out through much colder conditions as long as they were able to take in more energy from food than they burned trying to find it. Then wolves returned to the American West.

The Food Web Surrounding Wolves

After an absence of half a century, wolves came back to Glacier during the 1980s, trotting across the border from neighboring Canadian wildlands. Suddenly, this Rocky Mountain landscape held more carcasses of deer, elk and moose, and those of us who frequented the slopes began to discover a few scavenging grizzlies later and later into the frozen season. One valley, with prime wintering grounds for hoofed herds, hosts a big male silvertip grizzly that I’m not sure ever holes up to snooze anymore.

Wolverines, with their unsurpassed nose for leftovers, can find more meals now as well. So can wintering bald eagles and golden eagles, along with northern ravens, which often follow wolf packs on the prowl. Wildlife biologists tracking the wolves discovered them taking over fresh kills made by mountain lions. In many cases, the packs seemed to be honing in on the sight of circling ravens or the birds’ excited calls in order to find the stealthy cats and drive them off their prize. Before wolves were reintroduced to Yellowstone National Park in the mid-1990s, cougars had expanded their range to include broad valley bottoms. After the wolves’ return, the cougars retreated to the steeper, more broken upland terrain they had normally hunted.

Animals ranging from jays and magpies to martens and black bears glean scraps from wolf-killed carcasses. Coyotes are on that list of opportunists as well, but the wolves are lethally intolerant of their closest kin. In fact, Yellowstone’s new wolves quickly reduced the number of resident coyotes by nearly half, and forced survivors to take up life in smaller, more scattered territories. Coyotes behave much the same way toward their smaller relatives, suppressing the numbers and territories of foxes. So, where wolves move in, coyotes end up marginalized while foxes thrive. That in turn shifts the odds of survival for coyote prey such as hares and young deer, as well as for the small rodents and ground-nesting birds the foxes stalk. These changes affect how often certain roots, buds, seeds and insects get eaten, which can alter the balance of local plant communities, and so on down the food chain all the way to fungi and microbes.

Trophic Cascades: The Trickle-Down Effect

Ecologists commonly depict the structure of natural communities as a pyramid. The different layers are known as “trophic” (or feeding) levels. Green, solar-powered organisms — plants — form the foundation. On that broad base of primary producers rest layers of vegetarian species. Meat-eaters then stack up in smaller blocks above the herbivores until only the predators that have few or no predators themselves remain at the pyramid’s peak.

Experts used to assume the overall richness of an ecosystem was determined by bottom-up influences — that is, by the fertility of the soil, climatic conditions such as annual precipitation, disruptions such as flooding or wildfire, and other environmental factors that bear upon plant growth. Only recently did researchers begin to notice how the addition or removal of a dominant predator — say, a jaguar or killer whale — reverberates through all the lower layers of the pyramid. This top-down effect is known as a “trophic cascade.” Picture water spilling from a point source: The main flow fans out as it descends, splitting and splitting again, with a few streams jetting away to one side or another, then flowing on in more rivulets and arcs of spray.

Wolves are one such predator. This endangered species’ natural recolonization of the Glacier Park area and subsequent reintroduction to Yellowstone sparked an array of close scientific studies, and the results are an ongoing revelation. At the start, the elk in Yellowstone were, in the view of many experts, overpopulated and degrading their range. Herds practically camped in areas such as brushy wetland meadows and riverside flood plains, concentrating on favorite foods such as willow, aspen and cottonwood. Over the years, those woody plants became pruned into misshapen bonsai forms by elk teeth. Finding a young one taller than shoulder height was rare. In quite a few places, the aspen stands were no longer reproducing at all. Some had already died out.

Predictably, after the wolves arrived, their population grew while elk numbers fell. Yet within a decade, the wolf and elk populations started to approach equilibrium. Lately, wolves have actually declined in Yellowstone, partly because food is no longer as readily available, partly from disease, and partly because wolves limit their own density within a given range through deadly fights over territories. From the standpoint of the ecosystem, the most important impact wolves had on Yellowstone elk was not simply readjusting the size of herds, but also causing them to spread out into different areas and keeping them on the move.

Relieved from the pressure of constant browsing, long stems shot up from the clubbed-looking shrubs and trees. New saplings arose from ground level. Groves thickened, attracting more songbirds and small mammals. The roots of recovering vegetation stabilized the shores of waterways. Lured by the flourishing woody plants, beavers moved in and raised families. Their dams further countered stream bank erosion, and at the same time created new pond and marsh habitats for moose, otters, mink, wading birds, waterfowl, fish, amphibians and more. Lush regrowth along the edges drew still more songbirds, and the burgeoning supply of insects fed nestlings. The insects dropped off overhanging leaves into the waterways, nourishing trout as well.

As these trends continue into the future, entire watersheds will become more productive and able to support a wider diversity of species. They’ll also become more drought-resistant, with runoff water stored in beaver ponds and side channels able to help maintain streamflows through the hottest, driest months.

Glacier Park has denser, more varied forests where white-tailed deer abound, so the wolves there haven’t been as tightly focused on elk. Just the same, the recovery of some heavily browsed sites has been as dramatic as in Yellowstone.Long reviled as beasts of waste and desolation, wolves are looking more and more like creators of abundance and stability. Squint a bit, and you may even see generations of wolves in the keen senses and grace of elk, in the long-legged bulk and power of moose, in the electric reflexes of deer. Or, as poet Robinson Jeffers put it: “What but the wolf’s tooth whittled so fine / The fleet limbs of the antelope?”

Surprising Keystone Species

A trophic cascade doesn’t always have to involve a top predator. Back in the late 1960s, zoologist Robert Paine removed the starfish known as “ochre stars” from sample areas on the coast of Washington state. Active, aggressive hunters, ochre stars gorge on mussels. Lose that single predator, and thick beds of rapidly proliferating mussels take over, squeezing out barnacles, algae, snails, sponges, tube worms, sea squirts, and the rest of the remarkable mix of marine life usually at home in the intertidal zone. With ochre stars, Paine introduced the idea of a “keystone species,” defining it as one that exerts an outsized effect within an ecosystem, not necessarily through sheer size, number or biomass, but because of the pivotal role it plays.

Sea otters aren’t quite at the apex of the food chain along the North Pacific coast, for they can fall victim to sharks and killer whales. However, the otters dine on a smorgasbord of mollusks, crustaceans and, most of all, sea urchins. With the densest fur of any animal — 650,000 hairs per square inch — they were once hunted to near extinction for their pelts. Not long afterward, people noticed kelp beds that had served as the otters’ preferred habitat turning quite sparse or vanishing altogether. With the otters gone, it turned out, an exploding urchin population was gnawing its way through those submarine thickets of giant algae. Producing as much organic material per acre as tropical rain forests, kelp forests serve as sheltering nurseries for all kinds of juvenile fish, including commercially valuable species. Where kelp was most abundant, humans harvested it to make additives for products from soap and fertilizer to ice cream and jelly. Here, then, was a trophic cascade that tumbled down through unexpected levels and then washed onto us.

Vegans as Ecosystem Engineers

In another type of trophic cascade involving a keystone species, the lead role is played by a vegan: the African elephant. Consuming upward of 400 pounds of plants per day in the case of large males, these titans rip down tree limbs for meals, girdle tree trunks by stripping off nutritious bark, and simply push smaller trees over to get at the branches. As for shrubs, elephants not only eat the stems but tear whole plants to pieces, uproot others and trample still more underfoot while foraging.

When fully grown, elephants are virtually immune to predators, and herds tend to increase until checked by drought, food shortages or disease. At high population levels, their quest for food can transform wooded habitats into open plains. In cooperation with wildfire, elephants also maintain existing savannas by removing the woody plants that inevitably invade grasslands. Elephants shape the woodland-savanna balance in an ecosystem by determining the proportions of grazers such as gazelles, zebras and wildebeest to woody plant browsers such as giraffes and kudus, and of lions prowling the plains to leopards waiting to pounce from an overarching tree limb. That is, elephants shaped the communities in which our primate ancestors developed, stood upright and started walking toward the future.

Ecologists sometimes refer to elephants as “ecosystem architects” or “ecosystem engineers.” Here in North America, grizzlies serve the same function. In addition to their effects as predators and scavengers of hoofed animals, the big bears fertilize streamside habitats with their waste and the remains of the salmon they eat. (Both are rich in nitrogen and other essential nutrients.) Grizzlies also distribute thousands of seeds from shrubs after eating the berries, and they rank as the chief animal earth-movers of the upper elevations in portions of the Rockies. Excavating acre upon acre to get at hibernating rodents and the bulbs and starchy roots of various herbs, they bring up nitrogen from deeper soil levels just as a farmer does when tilling fields. The seeds that fall into such freshly turned soil yield a more robust crop of new alpine and subalpine plants than seeds in undisturbed patches. Next time you’re on a trail in grizzly range, instead of recalling some cheesy horror movie scene involving monster bruins, try thinking “heavyweight wildflower gardeners.” It can’t hurt.

Nature Is a Community

Everyone seems to have an opinion on ecology these days. Keep in mind, though, how new this field of science actually is, and how much all of us have yet to understand. Henry Ford had invented the automobile before biologist Ernst Haeckel even coined the term “ecology” early in the 20th century. The word didn’t enter popular vocabulary until the 1960s.

Feeding-level pyramids, top predators, trophic cascades, keystone species, ecosystem engineers — these are all different expressions of the central fact that everything in an ecosystem is connected to everything else. A natural community is by no means just a collection of individual species. Its vitality comes from the relationships between those organisms — the interactions, the flow of energy and nutrients from each life to the next.

Comparatively rare to begin with, most of the world’s apex carnivores are imperiled at present, and many keystone species are also at risk. There may be no more important lesson from the young science of ecology than this: If we want to keep ecosystems healthy and resilient, the first step is to pay closer attention to the way nature does this from the bottom up, and back down again from the top.

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Douglas H. Chadwick is a wildlife biologist and the author of 11 books — most recently, The Wolverine Way (Patagonia Books, 2010) — and hundreds of magazine articles on natural history and conservation. He conducts research on wolverines as a volunteer in Glacier National Park and serves as a founding board member of the conservation land trust Vital Ground.

http://www.motherearthnews.com/nature-community/keystone-species-zm0z11zrog.aspx

Organic Pest Control: What Works, What Doesn’t

Organic Pest Control: What Works, What Doesn’t

Posted for June/July, by Barbara Pleasant, Mother Earth News, motherearthnews.com

Last fall, MOTHER EARTH NEWS launched our Organic Pest Control Survey to learn more about what works and what doesn’t when it comes to limiting insect damage in organic vegetable gardens. About 1,300 gardeners from across North America responded, providing new, region-specific insight into organic pest control.

Our survey had strengths and weaknesses. It included opportunities for open comments, which became the source for the practical tips in this article. But, although we asked many questions about specific methods, we failed to always list chickens and ducks, which we learned many gardeners regard as essential players in controlling Japanese beetles and other garden pests.

We were surprised by some of the results. For example, we suspected gardeners would report that coping with various root maggots was a challenge, but 90 percent of respondents reported getting good control with crop rotation. Similarly, flea beetles didn’t make the list of worst pests because most gardeners achieve good control by using row covers and growing susceptible greens in fall rather than spring.

Ultimately, the survey revealed 12 widespread garden pests that give gardeners grief. Here are the nitty-gritty details, including down-in-the-dirt advice on how to manage each pest, plus details on which pests are the worst in each region. (To see an illustration of each of the worst pests, click on “Image Gallery” above.)

1. Slugs took top honors as the most bothersome pest in home gardens, with 55 percent of respondents saying the slimy critters give them trouble year after year. Handpicking was highly rated as a control measure (87 percent success rate), followed by iron phosphate baits (86 percent) and diatomaceous earth (84 percent). Opinion was divided on eggshell barriers (crushed eggshells sprinkled around plants), with a 33 percent failure rate among gardeners who had tried that slug control method. An easy home remedy that received widespread support was beer traps (80 percent success rate).

Relying on bigger predators — such as chickens, garter snakes and ducks — appears to be the most dependable way to achieve long-term control of garden slugs, as well as several types of beetles, cutworms and many other pests. Ducks are reportedly sharp slug-spotters, whether you let them work over the garden in spring and fall, or enlist a pair to serve as your personal pest control assistants throughout the season.

“Hungry ducks follow me around the garden daily. They love slugs and turn them into eggs,” commented a Mid-Atlantic gardener with 10 to 20 years of experience. In the Pacific Northwest, several longtime veterans of slug wars said ducks are a gardener’s best (and most entertaining) way to end chronic problems with slugs.

2. Squash bugshad sabotaged summer and winter squash for 51 percent of respondents, and even ducks couldn’t solve a serious squash bug problem. Most gardeners reported using handpicking as their primary defense, along with cleaning up infested plants at season’s end to interrupt the squash bug life cycle. The value of companion planting for squash bug management was a point of disagreement for respondents, with 21 percent saying it’s the best control method and 34 percent saying it doesn’t help. Of the gardeners who had tried it, 79 percent said spraying neem on egg clusters and juvenile squash bugs is helpful. About 74 percent of row cover users found them useful in managing squash bugs.Several respondents pointed out that delaying squash planting until early summer and growing the young plants under row covers results in far fewer problems with this pest. This makes sense because natural enemies of squash bugs become more numerous and active as summer progresses. Until then, keep scraping off those egg clusters, and handpick as best you can.

Three readers shared this tip: In the cool of the morning, place open pizza boxes beneath squash plants. Jostle the plants and let the adult and juvenile squash bugs fall into the boxes, and then slide your captives from the boxes into a pail of soapy water.

A creative idea from Editor-in-Chief Cheryl Long is to create a simple Squash Bug Squisher out of two thick boards and a hinge. Check out how to build the squisher, plus read comments from fellow readers who are battling squash bugs.

3. Aphids were on the watch list of 50 percent of respondents, but the success rates of various control techniques were quite high. Active interventions, including pruning off the affected plant parts and applying insecticidal soap, were reported effective, but so were more passive methods, such as attracting beneficial insects by planting flowers and herbs. Several readers noted the ability of sweet alyssum and other flowers to attract hoverflies, which eat aphids. “We attract a lot of beneficials by planting carefree flowers in the vegetable garden, including calendula, borage, zinnias, cosmos and nasturtiums” (Midwest, more than 20 years of experience). Other respondents commented on the importance of having some aphids around to serve as food for ladybeetles, hoverflies and other well-known beneficial insects.

4. Imported cabbageworms came in fourth, with a 47 percent “disapproval” rating. If you see these little white butterflies in your garden (see the “Image Gallery” for an illustration), take action to protect your brassicas before the cabbageworm moths lay eggs. Two widely accepted biological pesticides, Bt (Bacillus thuringiensis) and spinosad, received remarkably high effectiveness ratings: 95 percent for Bt and 79 percent for spinosad. Row covers had a reported success rate of 82 percent, while companion planting and garlic-pepper spray had disappointing failure rates in excess of 30 percent.

Several respondents said they rely on paper wasps to control cabbageworms. “They’re friendly, docile and voracious eaters of cabbageworms. My garden is full of cabbage butterflies, but I’ve yet to see a single worm; the wasps beat me to it” (Mid-Atlantic, six to 10 years of experience). To attract paper wasps, place bottomless birdhouses in the garden to provide nesting sites. Gardeners in the South, Mid-Atlantic and Midwest noted that cabbageworm populations drop if yellow-jacket nests are nearby, which enhances the success of fall cabbage-family crops.5. Squash vine borers had caused problems for 47 percent of the survey respondents. The best reported control methods were crop rotation and growing resistant varieties of Cucurbita moschata, which includes butternut squash and a few varieties of pumpkin. The C. moschata varieties are borer-resistant because they have solid stems. Interestingly, if you’re attempting to fend off squash vine borers, lanky, long-vined, open-pollinated varieties of summer squash (zucchini and yellow crookneck, for example) may fare better than hybrids, because OP varieties are more likely to develop supplemental roots where the vines touch the ground. Many gardeners dump soil over these places, so if squash vine borers attack a plant’s main stem, the plant can keep on growing from its backup root system. Because borers attack stems, compact hybrids, which tend to grow from one or two main stems, are naturally more susceptible.

One tactic is to wait out the borer’s egg-laying season. “To avoid squash bugs and squash vine borers, planting vining crops late and covering them with row covers until the first female flowers has been effective for us” (Midwest, six to 10 years of experience).

6. Japanese beetles slid in at No. 6, which is surprising because they don’t pose problems in extremely hot or cold climates. Forty-six percent of respondents reported working in the unwelcome company of Japanese beetles, with handpicking being the most popular control method. Some gardeners grow trap crops of raspberries or other fruits to keep Japanese beetles away from plants. Several commonly used interventions — garlic-pepper spray, milky spore disease, pheromone traps and row covers — had high failure rates.

Numerous respondents said chickens ended their problems with Japanese beetles, with guinea fowl and ducks also recommended for ridding areas of Japanese beetle grubs and adults. Even if you don’t let your chickens scratch in your garden, your handpicking may be more enjoyable because you’ll have something tasty for your birds when you’re finished collecting the beetles. In late spring, when Japanese beetle larvae are close to the soil surface, letting wild, bug-eating birds work over the area can have a lasting impact, too. Several readers shared that having nesting pairs of robins and bluebirds (which feed insects to their young) is the best way to keep Japanese beetles from getting out of hand.

7. Tomato hornworms claimed the No. 7 spot, and were of concern to 42 percent of our survey respondents. Bt and handpicking were the preferred control methods, and several folks commented that tomato hornworms are among the easiest garden pests to handpick (probably because they’re large, easy to spot and produce a telltale, pebbly trail). Many gardeners reported seeing tomato hornworms often covered with rice-like cocoons of parasitic braconid wasps. “I had a lot of tomato hornworms this year, but the wasps took them out! Just like in the photos online and in bug books!” (Mid-Atlantic, more than 20 years of experience). Gardeners named zinnias and borage as good companion plants for reducing hornworm problems.

8. Cutworms were a concern for 41 percent of respondents, and effectiveness ratings for using rigid collars (made from plastic drinking cups or cardboard tissue rolls) to protect young seedlings from damage were amazingly high (93 percent effectiveness rating).

A common practice to reduce cutworm damage is to cultivate the soil’s surface once or twice before planting and hope robins and other bug-eating birds will swoop in to gather the juicy cutworms. Big, sturdy seedlings are naturally resistant to cutworms, so many gardeners said they set out seedlings a bit late to avoid cutworm damage.

9. Grasshoppers were a problem for 40 percent of respondents, and they seemed to be getting worse. We received many reports that increases in rainfall seemed to trigger an explosion in grasshopper populations. Chickens and guineas reportedly give good control by gobbling grasshoppers, but keep an eye on your poultry helpers to make sure they don’t harm crops. Gardeners described two interesting setups incorporating chickens for managing hoppers: a fenced garden with a fenced chicken “moat” around its perimeter, and a series of three small fenced gardens, each with a gate into the chicken yard for easy rotation of pecking services. (Sound cool? Check out these instructions on how to build your own chicken moat.) If grasshoppers are getting worse at your place, you may need chickens more than you think.

10. Cucumber beetles wouldn’t be so bad if they didn’t transmit deadly bacterial wilt to cucumbers and melons, but as it is, 39 percent of our respondents named them as serious garden pests.

Neem, handpicking and good garden cleanup (removing all plant debris) were all rated as effective control measures, and once again poultry received many honorable mentions. Row covers earned more widespread use for the control of cucumber beetles than for any other pest, with more than 80 percent of people who had tried row covers reporting them to be effective.Seventy percent of gardeners who’d tried companion planting said this method works for controlling cuke beetles, and 64 percent of people who’d tried yellow sticky traps reported these work.

11. Corn earworms were pegged as serious pests by 37 percent of respondents, many of whom get easy relief by using instruments ranging from oil cans to eyedroppers to add a few drops of canola or olive oil into the tips of ears, right when the silks start to show. Others reported using a standard solution of Bt in the same way, and several experienced gardeners pointed out the value of choosing varieties that have tight ear tips.

The corn earworm comments included several mentions of the ease with which earworm damage disappears if you pop off the end of the ear, thus making this pest not such a big deal. Raccoons, on the other hand, were reported to be a big deal, which was the main reason many gardeners gave for not growing corn. “If I plant sweet corn, the raccoons always eat it unless I fence them out” (Midwest, 25 years of experience).

12. Whitefly problems may be on the rise, because whitefly-plagued gardeners (36 percent reported a problem) often used exclamation points to emphasize their frustration with these tiny sucking pests. Insecticidal soap earned a high effectiveness rating (90 percent), though many respondents said they use Dawn or other dishwashing liquids rather than regulation insecticidal soap. (Caution: Some research has found that repeated use of soap or detergent sprays can reduce yields.)

Broad-Stroke Pest Control

Along with working to improve your soil and thus grow healthier, more pest-resistant plants, several other common-sense approaches echoed through the comments sections of our survey. “The best way to beat the bugs is to plant more than you can use yourself. You can always give the surplus away” (North Central/Rockies, six to 10 years of experience). Others pointed out the advantage of setting the stage for beneficial insects and then simply standing back. From the Midwest: “I am willing to overlook some bug damage in order to provide good habitat for the beneficials reproducing all though the gardening season.” From the South: “A balance of insects is the goal, and ‘good’ and ‘bad’ insects both have to eat.”

Garden Pest Control Trends

Pest Control on the Wing

“Wild birds are a huge help, and gardeners should be encouraged to provide both nesting habitat and feeding stations for them. The bluebirds, flycatchers and other birds that live on my property spend a lot of time around my gardens catching bugs. The much-despised house sparrow is also a terrific boon to gardens, so urban gardeners would be well-advised to put out feeders even if that’s the only bird they will attract” (Maritime Canada, six to 10 years of experience).

Are Six-Legged Changes Afoot?

One of the questions we asked in our survey was this: During the past three seasons, have there been noticeable changes in the insect activity in your garden? Thirteen percent of gardeners reported they’d had many more pest problems, and 29 percent reported slightly more problems. Several respondents noted that increases in rainfall during the past few seasons seemed to be associated with more grasshoppers. Also, the appearance of a new, exotic insect, the marmorated stink bug, has brought new pest control challenges to gardeners in Pennsylvania and nearby states.

The Value of Beneficials

Seventy percent of survey respondents said they work to provide habitat for beneficial insects. Here’s what they said about whether this effort had helped to reduce pest problems:

Seems like it has helped a great deal            32 percent

Seems it has been somewhat helpful             49 percent

Seems to have helped with some pests         6 percent

Doesn’t seem to make any difference           13 percent

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Top-Rated Natural Methods for Controlling Common Garden Pests

Aphid: Insecticidal soap, attracting beneficials, horticultural oil

Armyworm: Bt (Bacillus thuringiens), handpicking, row covers

Asparagus beetle: Poultry predation, neem, handpicking

Blister beetle: Poultry predation, neem, handpicking

Cabbage root maggot: Crop rotation, beneficial nematodes, diatomaceous earth

Cabbageworm: Bt, handpicking, row covers

Carrot rust fly: Crop rotation, beneficial nematodes, diatomaceous earth

Colorado potato beetle: Poultry predation, neem, handpicking

Corn earworm: Bt, horticultural oil, beneficial nematodes

Cucumber beetle: Poultry predation, neem, handpicking

Cutworm: Rigid collars, Bt, diatomaceous earth

Flea beetle: Insecticidal soap, garlic-pepper spray, row covers

Harlequin bug: Handpicking, good garden sanitation, neem

Japanese beetle: Handpicking, row covers, milky spore disease

Mexican bean beetle: Poultry predation, neem, handpicking

Onion root maggot: Crop rotation, beneficial nematodes, diatomaceous earth

Slugs: Handpicking, iron phosphate slug bait, diatomaceous earth

Snails: Handpicking, iron phosphate slug bait, diatomaceous earth

Squash bug: Handpicking, good garden sanitation, neem

Squash vine borer: Growing resistant varieties, crop rotation, beneficial nematodes

Stink bug: Handpicking, good garden sanitation, neem

Tarnished plant bug: Handpicking, good garden sanitation, neem

Tomato hornworm: Bt, handpicking, row covers

Whitefly: Insecticidal soap, attracting beneficials, horticultural oil

Worst Garden Pests by Region

Ever wondered which pests thrive in your region and how your region compares with others in North America? The information in our regional pest chart provides the breakdown.

http://www.motherearthnews.com/organic-gardening/organic-pest-control-zm0z11zsto.aspx

OIL POLITICS: Forty years of resistance and mobilisation

Posted 16 June 2011, by Nnimmo Bassey, Next (Timbuktu Media), 234next.com

Milestones are important landmarks that prompt us to take time out to remember and reflect on what we have achieved, as well as to prepare for the challenges ahead.

After 40 years of campaigning, Friends of the Earth International looked back yesterday, June 15, 2011, on its contribution to the quest for environmental and social justice with considerable satisfaction.

Over the past decades, the federation and its allies have successfully campaigned for a raft of intergovernmental agreements regulating the disposal of wastes, and the use of chemicals such as pesticides and ozone-depleting substances.

It now seems inconceivable, for example, that countries once dumped their nuclear waste at sea, and that there were no controls over even the most lethal chemicals that persist and bio-accumulate in people and in nature. Environmental concerns such as these are now considered to be part of the everyday political discourse in many countries.

New and emerging challenges driven by the current neoliberal economic model pose new challenges and require strong, integrated and innovative responses. Our ecosystems are at breaking point: forests and biodiversity are disappearing, climate change is heating up the planet, and land and water resources are being polluted by oil, mining, and gas exploration. Communities and countries across the world are reeling from a volatile mix of financial, food and energy crises.

Friends of the Earth International, now a large and influential federation of autonomous environmental groups, was started 40 years ago by a small, dedicated and determined group of environmental activists from France, Sweden, the UK, and the US, who met in Roslagen, Sweden, on June 15, 1971. This meeting was to be the first of many passionate intercultural exchanges of concerns and ideas over the next four decades.

Originally a northern-based environmental organisation, Friends of the Earth International grew and evolved as many more member groups, especially from the Global South, joined it in the 1980s and 1990s.

Friends of the Earth International now boasts 76 national member groups around the world and has more than 2 million members and supporters. The federation joins forces with farmers, fisherfolk, indigenous peoples, women, workers, and young people, in our struggle for a better world.

Friends of the Earth Nigeria joined the federation in 1996 as a veritable part of the global environmental justice movement.

It is clear that real success can only be achieved if the underlying causes of problems are challenged. Settling for solutions that only deal with the short-term symptoms is pointless. Thus, Friends of the Earth International is committed to challenging the neoliberal model underpinning this short-sighted, profit-oriented perspective.

This is tackled in many different ways, from the local level through to the international. Campaigners in the federation work with local communities to defend their rights and promote food sovereignty and community-forest management, for example.

They are also well placed to mobilise people to pressure governments at the national level too, regardless of whether they are opposing bad decisions or proposing important new laws.

It also has the muscle to show up en masse at important environmental and economic summits – on climate change or international trade for example – to make sure that the world’s governments are aware of the impacts that their decisions may have on the daily lives of people and the environment, and to let them know what people around the world really think about these issues.

The federation will continue to track and challenge the activities of specific corporations, such as Monsanto or Shell, exposing their massive footprints on peoples and global environment and demanding change.

Challenging such powerful interests is not easy. Over the past 40 years, some of our members have paid a heavy price for their activism, including the abuse of their rights, imprisonment, beatings, disappearances, and even death.

But Friends of the Earth activists can count on their friends and allies around the world for support in their campaigns for the environment and for people.

Why does the federation run on the thematic pull to mobilise, resist, transform?

Firstly, effective resistance is impossible without widespread mobilisation. Commercial interests and political inertia are hard to shift, and people power is an absolute prerequisite for real and enduring change. Secondly, the federation harnesses its energies to resist the exploitation of people and their environments, together with its allies including social movements and local communities around the world.

And thirdly, the federation promotes the emergence of democratic structures, systems and processes in order to facilitate the transformation to sustainable and just societies. In other words, the federation is not a mere whistle-blower; it helps to create solutions and real alternatives to business-as-usual.

The federation is hugely diverse, and this diversity gives it strength. It is a kaleidoscope of different member groups – big and small, northern and southern, old and new – and all with different concerns, styles, structures and processes. This gives the network a truly creative and energetic dynamism and leads to powerful and multidimensional campaigns. It provides it with access to a treasure trove of knowledge systems and wisdom and inspires new ideas and concepts as well.

It is committed to building a movement for a new and better world based on solidarity, rather than competition and destruction.

Today, in its 40th year, it stands strong and proud with people around the world struggling for environmental justice and for the change we all so urgently need.

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Future Perfect: Technologies for low cost hydrogen fuel cells

 

 

Posted 17 June 2011, by Balakrishnan Ramachandran, EcoFriend, ecofriend.com

What’s happening right now:

Ever since the former US President George Bush Jr announced the Hydrogen Fuel Initiative in 2003 ,major efforts both in the US and in other countries are being made to bring about what is termed as the hydrogen economy, in order to reduce dependence on fossil fuels and mitigate the effects of global warming.

In a fuel cell hydrogen gas is pumped into the anode compartment of the cell where in the presence of the catalyst , it splits into protons and electrons. The protons pass through the membrane and combine with the oxygen pumped into the cathode compartment to produce water as the harmless by-product while the electrons are conducted away to generate electrical current.

This electricity can then be used with, for example electric motors to drive a vehicle. The idea is not new at all , having been postulated by the German scientist Schonbein as far back as 1838 . Fuel Cells have also been used to power space vehicles . The essential challenge today is to make this technology low enough in cost to get acceptance as the alternative to fossil fuel engines that power our cars and other personal transport vehicles and in other stationary applications. The two major areas that researchers are focusing on are, reducing the cost of the fuel cell itself . This, today is at around $60 per Kilowatt. The second area is to evolve cheaper means of Hydrogen production.

Trends:

The major cost element in the fuel cell is the platinum catalyst , both because it is a precious metal and because it gets easily contaminated. Two new approaches illustrate the importance researchers are giving to reduce Platinum usage.

1. Lung inspired Fuel Cell

Researchers at the Norwegian Academy of Sciences have used the human lung as the inspiration to design a system to deliver the Hydrogen and Oxygen gases through capillary like paths to interact with the platinum catalyst. This increases the surface area of interaction and reduces the usage of Platinum.

2. Plant inspired Fuel Cell

Another such approach by the Department of Energy’s SLAC National Accelerator Labs with researchers from the Stanford University and the Danish Technical University does away with Platinum altogether by using sunlight and water . Slender light absorbers of silicon dotted with newly developed catalysts are arrayed like pillars and these cause the water to split into Hydrogen as efficiently as fuel cells with Platinum catalysts.

The issues with Hydrogen production

The major process now used for Hydrogen production is by the process called “reforming” or steam cracking of natural gas. Making steam in itself, is an energy intensive process dependent on fossil fuels. Given that most fossil burning systems have efficiencies in the 33% to 45% range, the total energy balance in producing Hydrogen is none too attractive. Natural Gas is also a depleting resource and a long term Hydrogen economy cannot be predicated on the continued availability of Natural Gas.

The alternative is electrolysis of water, possibly sea water. This is an energy intensive process . This is viable if say solar or nuclear energy were to be available and we combine the low energy cost from these power generation sources with off-peak utilisation of the power to produce Hydrogen. With the nuclear power industry having had a major setback post Fukushima and with solar energy still in an evolutionary phase, this is still some years away, with some saying, even decades away.

New trends in Hydrogen production:

1. Cheaper Hydrogen from seawater without electrolysis

Reports of new research however suggest alternatives could emerge for the expensive electrolysis process of producing Hydrogen from seawater. The University of California , Berkeley, have reported using Molybdenum Oxo-catalysts and a Mercury electrode in untreated seawater to produce Hydrogen . This could lead to the deployment of sea-moored buoys or other rigs to produce Hydrogen from seawater that could be transported on-shore by pipelines.

Another team at the University of Purdue has reported success with using shaped components made up 90% of Aluminium and 10% of an alloy of Gallium – Indium – Tin. The alloy that is liquid at ambient temperatures slowly dissolves the aluminum that then reacts with the seawater to generate Hydrogen . In applications like Boats or Ships or Offshore platforms , this could be “Hydrogen-on-demand”. The Aluminum converts into a Hydroxide that can be recycled back into Aluminum.

2. Hydrogen from urine

Researchers at the University of Ohio , in looking for ways to reduce the energy cost of electrolysis, discovered that in urine, the Hydrogen molecules require only 0.37 volts to split whereas in water it needs 1.23 volts. They have postulated that the sewage treatment process could yield Hydrogen as the valuable by-product. Work is underway to scale up this process and eliminate the problem of bacterial action in sewage that converts urea into ammonia that reduces Hydrogen production.

In summary

The Hydrogen economy , essential for reduction and possible elimination of greenhouse gases ,is visualised based on the low cost production of Hydrogen that is utilized as the energy source in hydrogen fuel cells that can be used both for transportation and stationary applications . These new research approaches need to succeed quickly for this dream to be realized.

 

http://www.ecofriend.com/entry/future-perfect-technologies-for-low-cost-hydrogen-fuel-cells/