Ecological Parallels in the Montane Forests of Northern Luzon

Imagine walking up a steep gravel/dirt road and there is extreme coolness, dampness, and greyness, and greenery all around you. You are gradually absorbing something between mist and rain into your clothes. You are not sure if all this moisture in your clothes is from rain, dew from the leaves, or from sweat. You are noticing the plants around you. Many ferns, alders, oaks, pines, and large-leaved annuals crowd the disturbed spaces along the roadsides. The smell is damp, fresh, and of rich soil. The sounds you hear are the white noise of a small creek tumbling somewhere below you, a few distant chainsaws, and the occasional twitter of a small flock of songbirds. If you've spent any time in the coast ranges of the Northwestern North America, you know that I am pretty much describing the experience of walking through the forest in spring almost exactly. The crazy thing is, that I'm thinking about my experience walking through the montane forests of the Cordilleras of Northern Luzon in the Philippines at 1200 meters elevation and 17 degrees north latitude in December.

I was amazed at the ecological parallels I experienced in walking in these forest ecosystems in the Philippines half a world away from coastal Northern California and Oregon where I have spent a significant portion of the last 10 years. I wanted to write about the two distinct forest types that I encountered on my travels to Northern Luzon and share some of my thoughts about the ecological parallels between these ecosystems and some of the other places I have visited.

Mossy Forest:

This is a great photo showing the micro-ecological competition present on every available surface in the mossy forests. This photo looks exactly like some of the vine maple thickets I have hacked my way through in Western Oregon!

This is a typical montane mossy forest scene in the mountains of Northern Luzon above 1500 meters. There is a dazzling display of epiphytes in this forest. It is constantly moist and a substantial proportion of the precipitation that reaches the forest floor originates as fog.

I experienced many parallels between this forest and the mossy temperate rain forests in coastal Northwestern North America, especially in the structure of metamorphic geology, the structure of the plants in the forest, the sounds and smells there, and the feeling of being literally soaked by life. Mossy forests are on the high mountains, the windward slopes, and are directly exposed to whatever the Pacific Ocean to the east has to offer it. To me, the relationships between these two forests on two different continents were unquestionably related and parallel, rather than convergent in origin in the way scientists refer to Darwinian evolution. It felt connected to many of the indicators in the environment that felt familiar to me as what I can only describe as "Pacific." It could also be described stereotypically as "Jurassic" if you are the sort of person that grew up on classic dinosaur books. I was taken by being here, and regretted that I decided that I wouldn't pay the time and level of attention as a scientist and an animal that the place really demanded for me to have a relationship with it that was sufficiently useful to it.

There's no doubt that the mossy forests of the Philippines are in big trouble. Peril is really not a strong enough word to describe the likely fate of these forests in the not too distant future. I'm basing this assumption on three simple things...the value of the wood, the pervasiveness of the chainsaw, and the enthusiasm with which roads are being built. Indigenous leaders that have spoken out against loggers in the Philippines have been known to be killed or just disappear in the past. The Philippines has taken the stance of putting a complete logging ban on many of these forests, in essence taking a stance of complete denial that a problem exists and that people rely on the forest for survival. It's analogous to taking the stance of abstinence to prevent the spread of HIV. It is insanely ignorant and out of touch with cultural reality. The prices of logs have risen steadily as a result of the illegality of the logging and the scarceness of these rare and treasured hardwoods. The wood is beautiful and the markets are hungry for it. Chainsaws are already found in almost every village. They have become an everyday sound in the mossy forests. Evidence of their use is along every trail. This observation alone was extremely disturbing. The chainsaw is a deadly instrument in the hands tied to the wrong mind. The road situation is also grim. Not only have I seen rivers filled with sediment and massive landslides along every road, but these roads are constantly being extended into these forests. Bulldozers and excavators seemed to be parked on every road, constantly clearing landslides and pushing new road into impossibly steep slopes. In some ways, it was selfish of me to want to go there to see the virgin mossy forest growing on some of the more inaccessible mountains, but on even the most remote and steep slopes that I was able to visit, there were trails leading off to stumps. I think it's worth going there if I am able to tell other people about my primary experience. I don't know how it's not going to get worse.

Pine Forest:

The pine forests of Northern Luzon are equally special, but they have to be described in a completely different way. The pine in Luzon is referred to as Benguet Pine, (Pinus insularis) or (Pinus kesiya insularis) depending on who you ask. The forest that support Benguet Pine as it primary species are on the drier, leeward mountain slopes, usually between 1000 - 2200 meters. Being from California, it is hard for me describe a monoculture pine forest with as much novelty and reverence as I can describe a virgin tropical hardwood forest. How many species of pines are found in California? It's at least 15. In fact, some of the landscapes I found there, I would have guessed would be in Northern California had I been drugged and left there only to wake up and try to figure out where I was and what year it was.

The view to the east from Kiltepan Mountain. Is this in Mountain Province, Philippines or perhaps eastern Mendocino County, California? They are so similar.

Benguet Pine - Pinus insularis

The pine forest in the Philippines seems to have entered into a relationship with human beings for the same reasons pine forests in other places have. Why? You guessed it...grazing, logging, and fire. These things are very much integrated into the forest ecology. The forest ecology is struggling to transform at the speed with which cultural transformation of the humans that live there is occurring.  In the Philippines, fire is being suppressed and grazing is dying out as the industrial ethos begins to work its way into more remote areas. It seems as though logging of the pine forests is common and its rate increasing just as is apparent in the mossy forests. People are beginning to face some of the same problems in managing pine forests that we are experiencing in the Western US. Namely, an excess of fuel in the understory due to fire suppression.

The town of Sagada is intricately woven into the pine forests

Being a birder, I can't write about the ecology of montane forests of Luzon without mentioning the birds there and the parallels between them and the birds found in a typical coniferous forest in Northwestern California. The similarities are uncanny. First off, there is one species found in the pine forests that is the same as one found in pine forests in California and across the world. It is a bird that is arguably more symbiotic with pines than any other, the Red Crossbill (Loxia curvirostra). I can't overemphasize how amazing Red Crossbills are and how they have evolved into many different types that eat many different species of conifer seeds. Their specialization lies mostly in the varied shapes of their bilaterally asymmetrical bills. Loxia is one of only two bird genera in the world that display external bilateral asymmetry. I have met many people who have studied Red Crossbills, but I especially think of Ken Irwin, an ornithologist and amazing birder in Humboldt County, California who has dedicated a large portion of his career to this species. Check out this video to see how Red Crossbills extract seeds from cones using their asymmetrical bill:  http://www.youtube.com/watch?v=inzxNQSudqk

I was birding in Northern Luzon in December, so all of the songbirds were not breeding, but instead were in mixed multi-species flocks. Songbirds in North America exhibit the same behavior when they are not breeding in autumn and winter, then establish breeding territories and mostly ignore other species of birds in spring and summer. So, in birding, I focused on finding these big, noisy flocks of songbirds, then trying to find out what species were there. I found many species, and I decided I might put each montane Philippine bird side-by-side with its "theoretical ecological counterpart" from a northern California douglas-fir forest in early fall:

The core species:

Elegant Tit - Periparus elegans

Chestnut-backed Chickadee - Poecile rufescens

Mountain White-eye - Zosterops monatus

Golden-crowned Kinglet - Regulus satrapa

Just along for the ride:

Arctic Warbler - Phylloscopus borealis

Yellow-rumped Warbler - Setophaga coronata

Mountain Leaf-warbler - Phylloscopus trivigatus

Townsend's Warbler - Setophaga townsendi

Sulphur-billed Nuthatch - Sitta oeonochlamys

Red-breasted Nuthatch - Sitta canadensis

Philippine Pygmy Woodpecker - Dendrocopos macularis

Downy Woodpecker - Picoides pubescens

Citrine Canary-flycatcher - Culicicapa helianthea

Pacific-slope Flycatcher - Empidonax dificilis

Green-backed Whistler - Pachycephala albiventris

Western Tanager - Piranga ludoviciana

              Mountain Tailorbird - Phyllergates cuculatus

Wilson's Warbler - Wilsonia pusilla

The analogy was more striking than I ever would have expected, not just in form but in behavior. Of course, there were exceptions. I'm not saying that all of these birds exhibit the exact same behaviors. Also, there are many other species that could be conceivably present in either place, and would have no "counterpart" that would be quite the right fit in the other place. It's fun to draw these comparisons and think about ecology on a global scale. All in all, I enjoyed thinking about connectedness on so many levels during my visit to Northern Luzon. The scale of how all of these organisms and all of this biomass is connected is staggering. Just think about how much biomass Arctic and Yellow-rumped Warblers collectively transport between the boreal, temperate, and tropical forests of the world every year as they migrate back and forth!