Q. How would you describe the Highlands?
Eric Stiles: One of New Jersey's best kept secrets: rolling hills, scattering of farmland areas with some older urban areas that had been part of the industrial age. Again, not what you think of when you are driving the turnpike in New Jersey … which are people's first impressions. The Highlands of New Jersey is the national park for our urban areas, where people come to recreate. It's our drinking water supply, where when you turn on your water in urban areas, it's coming from the Highlands. The Highlands is making sure you have enough water and that it’s clean. It's a place where you can go for our National Wildlife Refuge, to see over a hundred resident bird species breeding there. It's this resource that's critical also for clean air -- it's the huge expanse of trees that are cleansing the air for the worst air pollution quality in the country. So, for all of those reasons -- human health as well as quality of life -- it's a critical area for our population.

Q. Is there an awareness of the Highlands?
Eric Stiles: Typically people's awareness of the world around them comes as the result of a crisis, and so with the drought we had in 2002, then people's knowledge of the Highlands spiked. All of the sudden there's odd days and even days for watering your lawn and that begs the question of where's my water coming from, so there's really been an increased awareness throughout the state of New Jersey and New York of where our water supply comes from. Awareness is really starting to increase. When you think of water, you think of the Highlands of New Jersey, which provides half our residents with water. It’s our drinking water fountain; it provides millions of residents outside of the Highlands with their water, so I think there's a sense of ownership or stewardship for that important area.

Q. That Highlands awareness is also creating a conflict?
Eric Stiles: A lot of people have moved to the Highlands because of quality of life. People are moving to those areas because of the huge forests, the beautiful hills, the vast wildlife. However it's that very desire to live there that's ecologically compromising the Highlands. It's a “Catch 22”, … being loved to death by ten acre lots that are grass and McMansion homes that consume large amounts of resources. … It's the impervious surface of new residential units that is primarily threatening the quality of water being exported. When you have about 10 percent of your watershed covered with asphalt or other impervious surfaces, the quality of the water really takes a nosedive as far as potability from the EPA standards. When you get around 2-3 percent impervious surface you start losing salamanders, all sorts of ecological thresholds. And again, that's that Catch 22: people are living there because it has clean water, things like salamanders, it has vast forests, but they want to be that last one in the boat. That is, once I've moved out to this location, then no one else can build, it's human nature, but we need to figure out the broader impact of all those activities. Again it's an area that will be loved to death ecologically.

Q. What makes a healthy Highlands forest … one that helps sustain the water supply?
Eric Stiles: The mountain forests in the northern Highlands are typical of what should be a healthy, vibrant forest. The best way to look at it first would be from the air. If you were flying over the Highlands in a plane, you would first notice the size and spatial expanse of the huge vast area where the forest is carpeted over these gorgeous ridge lines down into the valleys. You get a sense that size matters. Minimum fragmentation, minimum development. When you get below, if you're hiking through the woods in this vast forest, you get to see a very structurally complex forest, that has a very rich native assemblage: from a very intact large canopy, to a well developed sub-canopy. You go down a little bit further and you get a tall shrub, things like witch hazel and mountain laurel. Next you get down to the low shrubs where you have blueberries, huckleberry. You get down to the herbaceous layers: you may get some small native woodland flowers, ferns and even lower you get the leaf litter. It may be two to three inches in depth and that provides the bottom layer that is critical for a healthy forest. All those components are interfacing with one another. In a healthy forest, when a tree falls down, a sub-canopy tree erupts and replaces it in the gap, that light hole in the forest. So, it's a vibrant, structurally complex, ecologically rich forest that is very robust.

When the water falls from the clouds, it's interrupted by the canopy litter, the leaves that are out, and it may hit that and cascade almost like a ball coming down a series of pinball bumpers down to the forest floor. So it’s intercepted, it’s slowed down. And at the bottom it hits this very thick duff layer of leaf litter, where it gets absorbed like a sponge. Then it gets taken up right through the root system of this rich plant layer, which then filters the contents of that water. Because the water is coming down with a lot of chemicals -- air pollutants or other atmospheric deposition materials. It’s this cascading effect, it's this sponge-like property which then keeps it from running off in a sheet-like action, preventing massive erosion, and then it gets taken up by the plants with evapotranspiration and then gets reintegrated, some of this gets back into the atmosphere. But it gets cleansed by this rich biological system.

Q. The forest is the key to the water supply?
Eric Stiles: It acts as a sponge, a retainer of water. If that leaf litter wasn't there, if all the structures weren't there, you would have the rain water come directly onto the soil, that would then shoot off into massive soil erosion. As a result of this, you wouldn’t have the cleansing occurring at the root system which is pulling a lot of the chemicals out. So, it really acts as a critical component in both our water quality and quantity. It also allows for slow filtration into the base flow which feeds our streams, which feed our reservoirs, and it’s purifying that. It is a very cost effective water filtration purification system. It's either that or get the world's biggest Brita filter, and there in the Highlands it's currently occurring at no cost to us.

Q. Describe how surface water gets to the reservoirs.
Eric Stiles: In order to protect the reservoirs, you have to protect the landscape. The stream that may be feeding a reservoir like Oradell or Monksville is going to branch our like a root system, like our arteries and capillaries. It's going to spread out throughout the landscape. If you simply put a buffer around a reservoir, it's going to contribute and benefit the reservoir, but that's a very short-sighted myopic world view in my opinion. In order to really protect these areas you have to go out and follow the capillaries and follow the arteries throughout the landscape and protect that on a very large spatial scale in order to adequately protect the catch basin -- the bathtub -- being the reservoirs. If we didn't address these intermittent streams, if we didn't address the even small streams that are running through developments, -- that development might be discharging huge amounts of chemical cocktails into -- that then goes into a reservoir which would not be addressed by simple buffer around the reservoir itself.

Q. Describe what happens as impervious surface levels increase within a watershed.
Eric Stiles: The U.S. EPA has come up with all kinds of guidelines and standards regarding when impervious surface starts degrading our water quality. Human consumption is about ten percent. Impervious surface is typically seen in things like houses, roads, parking lots. Recent work done in New Jersey shows that even heavily impacted lawns, where heavy equipment works on a surface to put in new sod, are almost as impervious as asphalt. As you look at the entire watershed, when roughly ten percent or more of that watershed is impervious surface, then your water quality supply is jeopardized, because of the massive runoff of chemicals, and because the water isn’t recharging down to the base flow -- it is running off in a sheeting action and shunting or traveling into storm water drains and quickly out to the ocean. But impervious surface from wildlife perspective, once you get more than two to three percent -- for a species like salamanders, they start disappearing.

Q. What are signs of a forest’s health, its future?
Eric Stiles: The signs that you see in a live forest opposed to a dead forest are, for example, little oak seedlings and saplings. You see sub-canopy trees nearby a dead canopy tree, ones that would shoot up and fill that gap. You see multiple generations, if you will. You have an infant stage, you have a juvenile stage and an adult stage, of all the various species that are there. You also have the structural complexity. As an ecologist goes into these woods and sees this rich ground layer, you see this leaf litter, you see a good canopy, you know this is a healthy functioning system that exists in a very large unfragmented block of forests.

Q. How about an unhealthy or threatened forest?
Eric Stiles: From a high vantage point, if one is looking at a fragmented portion of the Highlands, you would see an intermixing of development, small wood lots, maybe some small agricultural areas. We have the issue that – when it comes to forests -- size matters. No one piece is very large. And then when you hike down from above, down to the isolated forest patches, you would see a simplified or dumbed-down forest. You might have a very old, well-defined canopy, but when a tree falls in that forest it’s not replaced. You typically are lacking the sub-canopy, lacking the small shrubs. When you get down to the shrub layer itself, it's comprised of only invasive plant species, things like Japanese barberry, stilt grass, and garlic mustard. Again you don’t have the rich structural stratification in these kinds of forests. You will see light gaps in the canopy that are not being replaced. When you look at the low vertical structure, it's invasive plant species that don’t perform the same functions as native plant species. When you look at the leaf litter, it’s completely absent because of Asiatic earthworms, who eat the leaf litter and leave nothing in return. There is no duff, there is no leaf litter. It’s just bare dirt.

So as a water drop falls down into a fragmented forest, it may or may not hit a canopy tree because of the gaps. Even when it does hit the canopy, it's going to fall a large distance to a shrub layer which is not as dense as our native shrub layer. Or that rain drop may or may not hit a shrub. Then it's going to hit the bare dirt. Again there's no leaf litter, there's no sponge. What's going to occur is massive runoff of the topsoil because you don’t have this sponge that's going to retain the water, that’s going to slow the absorption into the base flow. You're not going to have the purification or the root system to uptake that water for evapotranspiration and cleansing. It's a really impaired system that is leading to both the degradation of water quality and quantity.

Q. Beyond forest fragmentation, what are other impacts of development on the Highlands?
Eric Stiles: In a fragmented landscape you have also masses of impervious surface. Next to this degraded wood lot you're going to have a lawn, basically like a parking lot. These lawns are highly impervious, there are tons of chemicals being dumped on them, and a lot of water is being used to feed them. And as the rain hits that, that's going to shoot off and go right into storm water and out into the ocean. It is not going into base flow, it is not being purified, and will never reach a water foundation or water faucet in northeastern New Jersey.

Q. What is “edge”?
Eric Stiles: When you look at a fragmented landscape, “edge” would be any location where there's an interface between an ecological unit of one type or another. So edge would be the interface between a forest and an agricultural field. Or the distance between -- or that edge location if you will -- between the forest and the suburban lot. The influences which are harmful to that forest range far into the interior of that forest lot. Things like cat predation, deer browse, invasive plant species. The forest functions break down as the forest lots get smaller and smaller and they get further and further apart. So that fragmentation, those edge effects are threatening our water supply, our wildlife, and our forests -- which are all interdependent.

Q. Describe forest fragmentation.
Eric Stiles: Fragmentation is a continuum. There is no one hundred percent homogeneity, there is no one hundred percent sameness. The more cuts that one gets, the more fragmentation in this forest mosaic, the more it gets degraded. So, if you have a huge forest with a road and a house, the effects from that road can go up to two hundred meters into the forest interior. Things like salt water runoff. The effects from that house can also be far ranging: it may be importing Asiatic earthworms into their cultivated plants, which are then getting into the forests and decimating the forest litter layer. It becomes death by a thousand cuts. It's the cumulative impact of all this development and all this fragmentation which is threatening to upset our drinking water supply in New Jersey.

Q. The deer population can also impact forest health?
Eric Stiles: Deer prefer edge habitat. And we're creating the perfect world for them in the Highlands. Those edge habitats are where – historically -- they would have occupied burn areas from lightning strikes, or old beaver ponds before European colonization. And we're creating that by dicing and slicing up our habitats. And the deer are occupying those areas because there's more succulent vegetation. Our yards are like a buffet table for white-tailed deer. Well, then that allows the population to really increase, and there are no predators in New Jersey right now of any significance. Then deer go in and decimate forests. When you get above five to ten deer per square mile, you start seeing plant community impacts, where you're going to start lose some of the native plant species. Some areas in New Jersey have over a hundred deer per square mile. Now a hundred deer per square mile is an order of magnitude higher than can be sustained. The white-tailed deer are also being facilitated by our fragmentation. It’s a Pandora’s Box we’ve created and opened the lid. You're going to lose some of the structural complexity, and then the system starts to break down. It's that structure which is incredibly important for our water.

Q. How is an unfragmented forest protected from excessive deer browse?
Eric Stiles: In a very large forest you'll notice there are very few deer because there’s not as much food for them. The large contiguous forest has less food. When you think of your lawn, it's very lush, very green, and it has a lot of material that can be easily consumed. Deer typically like to browse on new growth. Just the very tips. As the forest size gets smaller, the deer are going to easily occupy the small blocks. It’s more accessible. So that fragmentation size matters. For deer, it’s a positive feedback method -- as habitat gets more fragmented, we increase deer. As you increase the number of deer, the habitat further degrades.

Q. Does forest size play a role in sustaining wildlife species?
Eric Stiles: There are many species that require vast tracts of forests -- red shoulder hawks, barred owls, warblers -- they are bio-indicators. They go hand in hand with these huge forests of the Highlands. Absent that, we start to lose species, bobcats, timber rattlesnakes, they all start “blinking off” those populations.

If you look at conservation biology theory, populations turn on and off over time. For example, a location might be beaver pond. The beaver comes in and it cuts down some trees, creates a pond in the forest, and that area is then colonized by frogs. Well, the pond fills in over time and it’s no longer a pond and not suitable for frogs. Well, individuals from that pond may move to a new pond created by a beaver and colonize that location. So, the old pond, that population might have turned off, would've collapsed, the new population at the new pond would have been colonized and turned on. Spatially wildlife populations are very dynamic, but they require the ability to move within these sites. If you put a major highway through a large forest, those smaller forest fragments can become isolated. As you fragment the habitat, wildlife won't move through those sites. Most interior birds will not cross a farm field to get to another wood lot. You put a bobcat on Route 80 and it’s not going to be pretty. This bobcat has a snowball's chance in hell in getting across Route 80 even if there’s another terrific forest on the other side. That fragmentation only allows populations to turn off, and it doesn't allow new areas to be colonized.

So, as one looks at the size of these forests, you look at the health of these forests, you can also look at the things that are there. One sees a bobcat in a ridge system of the Highlands, one knows it’s a very large forest. And because it’s a very large forest you know it is recharging and purifying the water.

Q. Describe the Highlands’ connection to bird migrations.
Eric Stiles: We have over one hundred species of birds that breed in the Highlands. For some it's a summer home, where they're coming from Latin and South America up to the forests of New Jersey, New England and Canada to breed. For other species it's a journey. They're following our ridge systems. The hawks are flying up off these ridge systems and continuing north. For other birds, it’s a stopover point -- they're leapfrogging through patches of forests, from South America up to their breeding grounds, including New Jersey. They fall from the sky about 3-4 in the morning, and they need these large forested tracts where they consume huge amounts of berries and insects, where they put on more weight for the next two- to three-hundred mile leg of their journey. For the Highlands, it's critical both as a place for year-round residents such as barred owls, the threatened species that live here year-round, to things that pass through, to birds that breed here like the warblers. So the Highlands is a critical location for birds in New Jersey.

Q. Are the Highlands at a turning point?
Eric Stiles: The Morris Canal was built because there was no more forest in New Jersey, no trees for charcoal to keep the furnaces going. We had to import logs from Pennsylvania, with considerable cost and effort. Then eventually what had been a decimated landscape primarily cleared for logging and agricultural purposes re-grew trees. That became the new crop, that was dominant land use up until post-World War II.

Then it was the Eisenhower dream of America. That is, let's put interstates everywhere to make commerce, traveling, and vacationing more available to the common man. As a result of that we opened up arteries for development. If you look at the commute time from Pennsylvania to New Jersey, putting in I-80 may sound good because you cut the travel time by 75 percent. However, it's almost like a new route or artery. These developments start building up around the interstate and sub-arteries that come off of these state highways. So now, what had been an artery that was unclogged is now clogged by fat cells, if you will. More and more traffic is going through there, it's more and more congested. So now it's more in theory that it sounds like it’s a commutable distance. Because if you go out to I-80, if you go out to Route 287, it can take you a half-hour to an hour to go five miles. Highways built to relieve congestion sometimes facilitate more congestion.

Q. Do you have a personal connection to the Highlands?
Eric Stiles: It's hard not to develop a personal connection to the Highlands. That personal connection is why people want to come and move out here. You immediately fall in love with the region by just going out and exploring it. Its beautiful ridges, its forests, its trout streams, … one of the most beautiful places on the east coast. I've been exploring this area for quite a while. I've lived in New Jersey for all but two years and it's one of my favorite places to go adventuring during the weekends. It's a terrific place to take your kids, to go explore and get outside. My favorite saying about New Jersey is when you get outside and say this is beautiful, it doesn't look like New Jersey. It's sort of like the joke of what exit do you live off of the Turnpike. There really are beautiful locations throughout New Jersey and the Highlands is one of its gems.

Q. Are the Highlands nationally significant?
Eric Stiles: The Highlands region is a long ridge system that provides drinking water for a lot of people. So it is a national health issue because of the drinking water supply. If we don’t protect our own drinking water that we consume, then we don't deserve anything but huge taxes that pay for these billion dollar treatment plants. It's cheaper in the long run to protect the areas where we want to recreate and enjoy, and then they also provide us our drinking water. Anything short of a national designation or national recognition is short-sighted.

You could be someone who's concerned about water quality and quantity. You could be someone who wants to go out and hike, or someone who wants to see two hundred warbler species. Millions of people come there to watch birds. You might simply be someone that loves the elegance of the forest; forest enthusiasts come out because it's a typical New England hardwood forest. That forest patch is going to be a home run for all those user groups. All those interest groups are coming together in the Highlands to try and conserve the same areas, albeit for different reasons. They all benefit.