Forestry 306

Field trips

The course will be structured around a set of field trips to different forest habitat types on the island. Course exercises will involve field sampling of biodiversity in most of the habitat types visited.

 

Emerald Pool This site is located close to the field station near the center of the island at 350 m above sea level, and provides a good example of rain forest at relatively low elevation (a rarity on the island and in the Caribbean generally). The terrain here is relatively level and the trail non-strenuous. This is a good location to spot the endemic Red-throated Parrot, as well as the Forest Thrush and the Rufous-throated Solitaire, the latter two spectacular birds found only in the Caribbean. Agouties and many fruiting plants are also common at this site.

 

	Secondary forest and tropical agriculture The forests at the field station are "secondary" forests that have re-grown following agricultural land use. These forests are thus representative of most of the forest land in the Caribbean region. We will also make observations in agricultural areas currently under cultivation, including a demonstration tropical organic farm at the field station (left).

 

Syndicate Trail                       The western slopes of Morne Diablotins (Devil’s Mountain) on the north end of the island are protected from hurricane disturbance, resulting in a lower montane rain forest that is the most spectacular in the entire Caribbean. Huge ancient trees (some >500 years and 2.5 meters in diameter) are common at the site. Large trees of a subset of species appear to be a critical habitat requirement for the Sisserou Parrot, the largest member of the spectular parrot genus Amazonas. The Sisserou is the "flagship" conservation species in the country: it is endemic to Dominica, critically endangered, is the national bird, and is even prominently displayed on the national flag. Syndicate trail is the best spot on the island to spot both the Sisserou and the congeneric Red-necked Parrot (or Jaco).

 

Morne Diablotins                       "Devil's Mountain" is the tallest peak on Dominica (1,447 m); the summit provides fine views of the entire northern third of the island. The trail starts at 600 m elevation, in forest similar to that found at Syndicate Trail, but then passes through several forest types as it ascends. As we climb, familiar species disappear and are replaced by higher elevation species, epiphytes become even more abundant, tree girth and height decrease, and the amount of annual rainfall increases. At over 1,000 m, we begin to see elfin forest, where the constant winds coming over the peaks keep the vegetation to less than 3 m tall. Short, thick, ancient, wind-swept shrubs dominate the landscape. From here to the summit, the trail is not for the faint of heart. While not dangerous, it is muddy and arduous, as this mountain peak receives 10,000 mm of rain per year, making it one of the wettest places on Earth. The “trees” that grow in the highest elfin forest on the way to the summit are so gnarled and twisted that making an easy trail would require too much cutting (and therefore cause erosion), so we will climb over and under and among the aerial roots, earning the stunning views to be had at the summit (left).

 

Boeri and Freshwater Lakes Boeri Lake (left) is a deep (>30 m) crater lake located at 869 m elevation on the slopes of Micotrin Mountain. The lake is accessed by a 1.5 mile (2.2. km) hike through upper montane and elfin rain forests. Freshwater lake (below) is another crater lake, the largest in Dominica, and we will visit this the same day. The hikes to and around the lakes pass through upper montane and elfin forest, providing a much easier time of exploring these habitats than the steep trail to Morne Diablotin. One of the birds we should see is the stunning Blue-headed Hummingbird, which lives only on Dominica and Martinique and is only at upper elevations. Themes to be addressed include freshwater ecology, watershed management, and factors influencing rainfall abundance and scarcity throughout the Caribbean.

 

Cabrits National Park Located at the extreme northwest corner of the island, Cabrits is located in the rain shadow created by Morne Diablotins. As a result, the park gets only one-tenth of the annual rainfall that the summit of the mountain gets (despite being less than 15 miles from the mountain), which creates a completely different habitat than any other found on the island. Rather than the lush, green rain forest that occupies the rest of Dominica, Cabrits is composed of deciduous dry forest, characterized by small-crowned, short-stature trees that are often covered with thorns (left). We should see several snake species as well as the Lesser Antillean Iguana. Dominica represents the best hope for this endangered, large reptile, where it is relatively common here despite being critically endangered on the other islands in its range. Many of the plants that occur here are found nowhere else on Dominica and are regionally and globally endangered.

 

Aerial Tram in Morne Trois Pitons National Park we will travel into the canopy on an aerial tram, which is a modified ski lift (left) that travels almost 3 km through the canopy of lower montane rainforest. The ride takes an hour to reach the highest point, when we will temporarily exit the tram to walk to a suspension bridge over 500 feet above the valley below. Another hour’s descent provides a unique opportunity to observe life in the rain forest canopy, which is usually completely out of reach for research or educational purposes.

 

 

Middleham Falls and Stinking Hole                       Also in the Morne Trois Pitons National Park and World Heritage Site, the falls are a two-hour hike through primary lower montane rain forest. In addition to the numerous plant, insect, and bird species that we will observe, we will pass Stinking Hole, a cave entrance where many of the 12 bat species native to Dominica live (left). If possible, we will be at Stinking Hole at dusk to watch the bats emerge from the cave entrance for their nightly foraging.

 

Valley of Desolation and Boiling Lake Dominica has eight active volcanic centers, though there are no open calderas spewing lava. Instead, the activity is below ground and in several areas sulfurous gasses break through to the surface (center). Where this occurs, the localized combination of increases in temperature with high levels of sulfur both in the air and soil make for a harsh environment in which only a few highly-adapted plant species can survive. Where too much sulfur and other minerals accumulate, even these few species cannot grow. The Valley of Desolation is a large area in the southern mountains where there is a mosaic of these specialized plants and barren areas. We will hike through this area to the second largest boiling lake in the world. The lake is literally boiling, as a result of geothermal activity (left). The all-day hike and exploration will provide many illustrative examples for discussing the local geology and soils, soil chemistry and physical properties, and the highly specialized physiology required by plants to grow in such harsh environments.