Recipe for a HealthyForest Canopy

E X P E R I E N C E Y O U R A M E R I C A

by Jim Wheeler

In 1850, close to 2,000,000 acres ofold-growth coast redwood forestcanopy mantled the coastal moun-

tains of California. Today, less than fourpercent of that canopy remains.

Old-growth (ancient) redwoodforests are not simply stands of big,beautiful trees — they are relativelystable, complex ecosystems dominatedby large conifer trees hundreds of yearsold. Some redwoods grow to be twothousand years old and more than 360feet tall.

Large trees are often widely spacedand highly individual, shaped overcenturies by windstorms, drought, andfire. These four ingredients: age, wind,drought, and fire combine to producethe gnarliest forest canopy in the world,one that supports entire ecosystems inthe sky.

AGE. The remnant old-growthredwood forests that exist in the

parks today are among the oldest forestson Earth. Redwoods reach the uppercanopy within 200-400 years, enablingthem to develop individual characteris-tics that create some of the mostcomplex tree crowns ever found.

Above 150 feet, primeval redwoodtrees develop massive limbs that cansupport tree-sized trunks growing onthem. Multiple trunks growing in onetreetop appears as a rounded silhouettefrom a distance. Previously logged, evenaged younger forests contain conifersless than 150 feet tall that all havepointed tops with young branches.

With time, deep organic soilsaccumulate on large limbs. Thirteendifferent species of plants, shrubs, andtrees, most of which normally grow onthe forest floor, grow in these soils. Thesoil mats provide homes to thousands ofinvertebrates, mollusks, earthworms,and salamanders.

WIND. During gale-force winds,branches or trunks from adjacent

trees knock against each other causingwounds or breakage. The injuries withinthe crowns allow light to pass throughthe canopy, which results in new sproutson trunks and branches. As a result oflongevity and responses to winddamage, many ancient redwoods haveextremely intricate crowns consisting of

multiple tree trunks, each supporting itsown system of branches — and all withinthe crown of a single tree.

Called reiterations, these trunksemerge from huge lateral branches thatoften rival the diameter of the largesttrees in other forests. One tree onRedwood Creek has 148 reiterationsbeginning about 150 feet above ground.From a distance, its broad crown caneasily be mistaken for several large treesgrowing close together.

DROUGHT. Although annualrainfall can exceed 80 inches, from

late May to November redwoodsexperience the dry season. Duringdrought years, some treetops die back.From across a river or a prairie, look atthe old redwoods — many display deadtops. Yet they are not dead. During wetyears a typical redwood will resproutseveral new trunks from just below thetop, developing a series of new leadersheading for the sky.

Amazingly, reiterated trunksdevelop root systems in accumulatedsoils at their base, aiding the whole treein water transport to its highest reaches.During the dry season, the lush, multi-faceted canopy soaks up moisture fromcoastal fog, and fog can account for upto one-third of the water a giant needsannually.

FIRE. Fire reaches the canopy in twoways: Lightning strikes an individual

tree, or low-intensity fires on the groundslowly smolder up the bark and into thecanopy. Either way, fire generates newsprouts — expanding and strengtheningcanopy layers.

AN UNSEEN WORLD RE-VEALED. Until recently, this

unseen world in the old-growth canopyremained a mystery. Few of us will eversee the gnarly treetop world of marbledmurrelets, red tree voles, and northernspotted owls.

Today, scientists use modernarchery and rope-based climbingtechnology to uncover entire ecosystemswithin the forest canopy — revealingage, wind, drought, and fire as themixture that makes a canopy complex.Exposing this unseen world is redefiningthe significance of remaining old-growthforests.

The scientific exploration of old-growth redwood forest canopies began in 1996 when Dr.Steve Sillett, seen here at 320 feet up in one treetop of Prairie Creek Redwoods State Park,began teaching at Humboldt State University. His research team discovered entire ecosystemsin the redwood canopy. Yet the canopy and the forest floor have much in common!Photo by George Koch

E X P E R I E N C E Y O U R A M E R I C A4

The unseen world of the redwood canopy holds just as much life asthe forest floor! Birds, berries, salamanders, conifers, lichens, bugs,and much more make up an entire ecosystem in the sky. Somespecies live their whole life in this lush climate-controlled refuge.

CanopyThe Tie That BindsBy Debbie Savage

The first thing I noticed when I moved to coastal California is the rain — up to 100 inches a year.I soon learned that the rain transforms every level of the forest into a colorful array of fungi in all

sizes, shapes, and textures, revealing a hidden world with names like fly agaric, witch’s butter, andturkey tail. Intrigued, I followed a trail of fungus from the forest floor to the canopy, searching for aconnection.

By maintaining a cool, moist environment, the canopy provides ideal habitat for over 300species of fungus. Fungus is a collection of filaments or threads that may extend for several milesbeneath the surface. These threads (hyphae) produce two types of fruiting bodies, mushrooms aboveground and truffles underground. Most fungi obtain nutrients by breaking down leaves, cones, andother forest litter constantly shed from the canopy.

Some fungi infect young tree roots to form a beneficial structure called mycorrhizae (from the Latin mycor for fungus, rhizafor root). By growing into the roots and extending out into the soil, mycorrhizae increase the tree’s ability to absorb water andelements such as phosphorus, zinc, manganese, and copper. These filaments also produce antibiotics to protect the roots fromdisease. In exchange, the fungi receive sugars from the tree’s root system.

Many forest animals rely on fungi in their diet. Chipmunks on the ground and flying squirrels in the canopy dig for truffles.Roosevelt elk, black bears, banana slugs, and millipedes graze on mushrooms. In turn, these animals disperse fungus spores in theirfecal pellets, and new fungi grow from the spores.

The more I learned the more I realized that fungi threads bind the old-growth forest community together. It is the threadthat connects the canopy to the soil and forms a vast underground transportation system for water and nutrients. Follow thatthread the next time you visit and see where it takes you.

fly agaricAmanita muscaria

By Lynne Mager

If you could take a red carpet rideabove the redwood forest and look

into the candelabra canopy, you wouldnotice tremendous fern mats attachedto the branches and tree trunks.Hovering above, you might glimpse thecircle of life existing inside and outsidethese hanging gardens.

Tree-sized limbs radiating fromthe 1,000 year-old redwood stemprovide a lofty perch for branches,bark, and needles falling through thecanopy. A whole flora of fungus rots thedebris into “canopy soils” — a richhumus similar to what you’d like toachieve in backyard compost. Have youlooked in your soil lately? Like anyhealthy garden, these soil mats fill withearthworms, bugs, and crustaceans.

Researchers who climb into thecanopy were 200 feet up a tree whenthey saw “in driving rain, on the side ofthe bark, this earthworm cruising athigh speed . . . just going for it.” Fromthe forest floor to the canopy, somecritters find their way to aerial gardens

Aerial Gardensthat offer protection fromterrestrial predators.

During the rainy season,the deep soils soak up waterand become a haven forepiphytes: plants that growon plants. One researcherfound over 1,000 pounds ofleather fern, the most com-mon aerial garden plant,growing in one soil mat.

Imagine flying your red carpet 100feet down into the canopy. Here chicka-dees, ruby-crowned kinglets, and browncreepers gorge on red and black huckle-berry thickets. An array of shrubberynormally found on the ground can alsogrow 300 feet above, roots firmlyembedded in rich soil mats. Evenwestern hemlock and Sitka spruce treessprout.

When the rainy season subsides,the gardens in the sky survive on waterdripping through the soil mats, acontinuous sprinkler system. What’s in

your backyard treetops? In the redwoodcanopy, “plants growing on plants”provide food, water, and shelter for anexquisite ecosystem that’s home tosalamanders, birds, and mammals,some of which live their entire livesamong the misty hanging gardens.

A bouquet of leather ferns, the mostcommon aerial garden plant, dangles fromthe crotch of a tree.Photo by Thomas Dunklin

Epiphytes: Plantsthat grow on plants.

Pacific northwest old-growth forestcanopies provide a home to one of

the rarest and most unique seabirds inthe world, the marbled murrelet. Noone knew where the robin-sized birdnested until 1973, when the first nestwas discovered on a large branch high ina colossal redwood tree — makingmurrelets the only non-tropical seabirdto nest in trees.

Most of the murrelets left inCalifornia nest in Redwood Nationaland State Parks. They are a “posterbird” for ancient trees: The murrelets’presence indicates a healthy forest.Today the forest is fragmented, a patch-work of old- and second-growth areas.With fewer places on high to land andraise a chick, these spotty-colored birdsare federally-listed as threatened.

As you stand — back arched, neckextended — trying to look into theround-top canopies at Prairie CreekRedwoods State Park, listen. At dusk ordawn, you may hear the sharp keer of amurrelet overhead. One adult is return-ing to the nest with food. If you areincredibly lucky, you will see the posterbird for a healthy forest speed throughthe sky like a bullet.

From theOcean to the

Redwood Canopy

Help Save the Marbled Murrelet!Predators such as ravens, crows,

and jays are eating murrelet eggs andyoung birds. While looking for strewngarbage, they find the murrelet’s nestinstead. Please attend to all food itemsat your camp and on the trails. Pleasedon’t feed any wildlife.Don’t make a good bird go bad!

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Marbled murreletadult on nest anda chick. Photos by

Ron LaValley

270 feet high

E X P E R I E N C E Y O U R A M E R I C A 5

Discovering the Unseen World

A 6-foot thick redwood limb

grows off the main trunk.

Soil builds up, allowing manytypes of plants to grow.

Top. To gain access to the canopy,Dr. Sillett’s team shoots rubber-tippedarrows from a powerful compound bow oversturdy branches up to 290 feet aboveground. Arborist-style rope techniques allowmovement within the crown, includingtraversing between tall trees. (Research inRedwood National and State Parks is doneby permit only.)

When mapping the crown, the teamestimates the wood volume and bark surfacearea of the main trunk, reiterated trunks,and limbs. Eventually they will be able toestimate the mass and surface area of eachtree’s leaves.

Right. Canopy researchers haveinstalled solar-powered sensorarrays that monitor microcli-matic conditions in the crown;find out the amount of waterstored in canopy soils; anddetermine how much water istransported through the trees’trunk, reiterations, and limbs.The results will inform the worldabout how much habitat bigcanopy provides for a myriad ofplants and animals.

by Kale Bowling-Schaff

Imagine living your entire life 250feet above the ground in theredwood canopy, breeding and

sleeping in thick, moist soil mats fullof tasty insects, well out of reach ofground-dwelling predators. If youwere a sticky-toed salamander capableof walking up a tree trunk, thisenvironment might make an idealhome.

The wandering salamander(Aneides vagrans) represents just onemember of an abundant communityof life high above the ground. Previ-ously, scientists observed this three-inch-long salamander in modestnumbers camouflaged among rottenlogs and rock crevices on the forestfloor. Now researchers who climbhigh in old-growth redwood treestrack populations of wanderingsalamanders that may never comedown at all. Thousands of them live

in the canopy.

Wanderingsalamandersthrive in treesmore than 400years old.However, with96 percent of

the ancient redwood canopy habitatgone, these tiny creatures haveresorted to living in debris piles leftbehind by logging. Due to this adapta-tion, wandering salamander popula-tions found from Del Norte Countysouth to Sonoma County seemrelatively secure. In contrast, amphib-ians worldwide continue to declinebecause they cannot adjust to habitatdestruction.

Will there be more suitablehomes for wandering salamanders andother canopy creatures as protectedredwood forests grow back? Onlytime — and our ability to protect acommunity in the treetops we seldomsee — will tell.

A SALAMANDERPARADISE

by Debbie Weist

To see real mammalian canopy action,get out your night vision goggles.

After hours, the infamous spotted owlhunts on silent wings. It might find one ofits favorite foods, the red tree vole. Thisdiminutive rodent feasts on fir needles, awaxy delicacy few animals can digest.With an abundant supply of needles in thecanopy, the voles rarely descend to theforest floor.

The spotted owl also snacks on thenorthern flying squirrel. These squirrelsfeast on lichen and subterranean fungi.The squirrels don’t really fly; they soarwith grace and agility up to 150 feet. Incontrast, they crawl awkwardly on theground, so they spend most of their livesin the treetops as well.

Both the squirrel and vole provideessential nutrients to sustain a healthyold-growth forest by depositing fungal

Mammals Above!

Mammal canopy list: These critterseither live in or forage in and around theredwood canopy:

hoary batbig brown batsilver haired batCalifornia myotislong eared myotislong legged myotiswestern red batred tree volechickaree (red squirrel)northern flying squirrelTownsend chipmunk

High in the ancient forestcanopy a plethora of mossesand lichens attach themselvesto branches. Mostly absentfrom younger forests becausethey take centuries to grow,lichens fix nitrogen from theatmosphere in their tissues.Eaten by northern flyingsquirrels or blown to the forestfloor, their nutrients leach intothe ground and feed all of theforest plants. Ancient treesprovide lichens a platform forgrowth and lichens feed thetrees, completing just one cyclethat binds the whole redwoodecosystem together.

spores and nitrogen-fixing bacteria withtheir scat (droppings). The trees rely onthese fungi as symbiotic partners innutrient absorption. From the smallestfungi to the smallest mammals to thetallest trees, a web of interdependenceexists in a world outside of our normalscope of vision � the redwood canopy.

A 2-foot diameter treetrunk grows on theredwood limb.

Monitoring the microclimate of a treetop ecosystem

Photos by Steve Sillett and George Koch

200 feet high

320 feet high

300 feet high