Saturday, March 1, 2008
Douglas Tallamy's "Bringing Nature Home"
I'm biased, but this book kicked some tail. A few years ago, to be honest, this would've bored me. Not so now as I'm far more conscious of what role my garden / landscape plays in the world around me. And as I start my garden, I want the right plants, and thankfully Tallamy has a nice list for all four corners of the States in the back, yet NEGLECTS the midwest and plains. So, I have no choice but to guess on this and trust my local nurseries, which he says not to do since the horticultural industry proclaims alien plant species native after 100 years or so, and a zone 6 plant in one part of the country native to a zone 6 area on the opposite end. But, dogwood, viburnum, elderberry, milkweed, and violets will be coming to my house en masse in two months.
He also has a nice long chapter, with images, of beneficial insects and why they are neato.
I took notes, so I give you note form. No interesting prose for you, but the ideas, if you read through, build to some pretty conclusive ideas: we can still save our environments from mass extinction if gardeners garden native. Huzzah!
We tend to have three distinct views on the value of nature: 1) need it to exploit it (for medicine or paper or what have you); 2) need it for aesthetic or moral reasons; 3) it literally sustains us. He argues that all three are necessary and valid in order to have greater biodiversity.
Open lawns are part of our evolutionary psychology—space helps us see lions and hyenas coming at us. It’s time to get over this because these threats are no longer tenable. So, plant over and understory trees; plant thick shrubs in foundation plantings, especially since most bird species nest in shrubs, not trees, and we garden for birds and butterflies (luckily, moths and butterflies are the #1 food source for birds and other animals, a win win if you ask this reader).
All we have left are patches of native places, and these have all but condemned many species of plant and animals to extinction (both because the habitat is small, but also because alien plant species more easily gain a foothold with less native competition).
--In our lifetime 95% of plant / animal / insect species pilgrims saw will be gone.
--Landscape ecologists say only 3-5% of all US land is undisturbed.
--As gardeners, we must lead by example and believe in E.O. Wilson’s concept of biophilia, that humans have an innate love for nature, and so will want more of it, nurture it, respect it.
--Biodiversity is easy to increase if we act before extinction (easier to get than fresh water or clean energy even).
--There’s more CO2 now in the air than anytime in the last 10 million years. I wonder though, what happens when the ice melts and we no longer have core samples with which to trace earth’s climatic history?
--1 hectar (2.5 acres) in Amazon has 473 tree species; PA has 134 species total. Now, how fast is THAT vanishing?....
--37% of world’s insects eat plants.
--96% of North American birds rely on insects, and the spiders that eat them, to feed young.
--Most insect species contain more protein than beef pound for pound. Yum. Omaha Steaks = Omaha Insects.
--Many common bird species decline at a rate of 1% per year!
--Within a century ¼ of all birds (globally) will be functionally extinct in ecosystems--so rare they play no ecologically important role. There are currently 9,000 bird species.
--Why insects don’t use alien plants:
1) Most are unpalatable (honeysuckle, buckthorn, burning bush, barberry, purple loosestrife)
2) Takes a long time for insects to adapt to chemical mix in leaves (millennia)
3) Insects / plant specialists – 1 needs the other, so insects shun aliens
--they evolved closely together symbiotically, they simply CAN’T eat aliens
--They evolved to beat specific plant defenses, time life cycle to them, learn to
find plant, ability to eat plant….
--5,000 aliens have invaded natural areas in North America
--Aliens do bad things, Mr. Will Smith:
--lower insect production
--exclude and hybridize with native vegetation
--alter frequency of wildfires
--alter availability of surface or ground water
--decrease diversity of soil biota
--deplete soil nutrients
--degrade aquatic habitats through soil erosion
--increase competitive pressure on endangered plant species
--degrade wildlife forage
--“Perfect” gardens are contrived plastic, and on their literal deathbed. Gardens are not and should not be perfect. I.E. they aren’t pest free, either—buying pest resistant plants does little to create biodiversity in the environment.
“Their study shows [Raupp and Sadof] that as much as 10% of the foliage in a garden can be damaged by insects before the average gardener even notices. This is exciting news. It tells us that most gardeners do not have a zero tolerance of insects in the garden and that maybe, just maybe, the populations of insects that create 10% damage levels might be large enough to support communities of natural enemies so diverse and numerous that the foliage damage levels never exceed 10%. I believe this utopia will be easier to achieve when most plants in our gardens our native.”
FUN FACTS OR "KNOWLEDGE GENERATES INTEREST, INTEREST GENERATES COMPASSION"
--One large sugar maple can sequester 450 pounds of co2 per year!
--One hour of mowing = 650 mile of driving, 800 million gallons of gas in lawnmowers each year, and $45 billion in lawn care (plus, think about all those frogs and spiders you kill)
--Blue jays bury nuts and seeds as caches like squirrels
--Tree and bush crickets use concave leaves to amplify mating calls
--Spittle bug creates bubbles of plant sap out of anus to cover itself up (human babies do this too I believe)
--30% of all animals are beetles
--Blister beetle causes blisters and an overdose is fatal, but also acts as Viagra (now, who would stand there and apply a beetle to your...)
--Moths and butterflies are largest food source for other animals