TEMPERATE, TROPICAL, AND SUBTROPICAL CONIFEROUS FOREST

LOCATIONS

Conifers occur in all continents except Antartica. Their distribution reflects the ancient Gondwana common contintent break up.

Temperate Coniferous forests are common in coastal areas in regions that have mild winters and heavy rainfall or inland in drier climates or montane areas. Temperate coniferous forests only occur in 3 and regions and 52 ecoregions around the world (Pacific Northwest, Valdivian forests of southwestern south America, Rain Forests of new zealand and Tasmania, the northeastern Atlantic (small pockets in Ireland, Scotland and Iceland), southwestern japan and east Black Sea. The Temperate Coniferous Forests biome is composed by 52 ecoregions.

The Tropical and Subtropical Coniferous Forests are predominantly found in North and Central America. México has the world's richest and most complex subtropical coniferous forests. The greater Antilles contain many endemics and relictual taxa. The Tropical and Subtropical Coniferous Forests biome is composed of 15 ecoregions.

BASIC DESCRIPTION

Conifer forests are familiar from the extensive forests of pines in the northern parts of America, Europe and Asia with temperate cool climates. But their natural distribution reflect a diversity that is much more extended. Tropical and subtropical conifer forests contain more that 200 species of conifers. Coniferous forests are classified in two major biomes: the Temperate Coniferous Forests and the Tropical and Subtropical Coniferous Forests.

Temperate evergreen forests are found in areas with warm summers and cool winters and vary in the kinds of plant life from needleleaf trees to broadleaf evergreen trees or a combination of these. Temperate conifer forests sustain the highest levels of biomass in any terrestrial ecosystem. Some trees have massive proportions in temperate rainforests regions. Generally, these forests are structured with only two layers, an overstory and an understory. Some forests may support a layer of shrubs.

The tropical areas experience low levels of precipitation and moderate variability in temperature. They are characterized by a high diversity of conifer species. Many migratory birds and butterfly species fly to these areas in winter. The Monach Butterfly (Danaus pexippus) flies through areas in Canada and the US to eventually concentrate in a few places in the forests of Mexico. The concentration of butterflies in the branches is so high that the combined weight of the butterflies makes the branches bend downwards. In Tropical and Subtropical Coniferous Forests, the thick canopy blocks the light in a way that the floor does not present an abundant underbrush. Commonly, ferns, fungi, and bryophytes are abundant. Some shrubs and small trees compose a diverse understory.
 

REPRESENTATIVE SPECIES

Typical tree species include pine (Pinus spp.), douglas-fir (Pseudotsuga spp.), cedar (Juniperus spp., Cupressus spp., Thuja spp.), fir (abies spp.), and redwood (Sequoia spp.). Pine forests support an herbaceous ground layer that may be dominated by grasses and forbs that support ecologically important wildfires. The moist conditions in temperate rain forests support a dominant herbaceous layer of ferns and forbs. These can be forest communities dominated by unusual huge trees such as: giant sequoia (Sequoiadendron gigantea), redwood (Sequoia sempervirens), and mountain ash (Eucalyptus regnans) that occur in western North America, southwestern South America, Southeastern Australia, and Northern New Zealand.

In the Tropical and Subtropical Coniferous Forests, the disturbance regimes, such as as fire and epizootics (insect swarms), vary considerably within this major habitat type. The small patches of natural forests have limited conservation value, nevertheless, corridors of different sizes are valuable. In certain areas, larger carnivores, such as mountain lion, jaguar, and wolf, are still present and playing an important ecological role. Large natural landscapes are important for the large home ranges of some species and for allowing fire as a naturally occurring disturbance.

KEY DESIGN CONSIDERATIONS

Collaborate across property boundaries to form biological corridors as small patches have limited conservation value.
Allow for large home ranges of large carnivores
Keep in mind that some species are highly sensitive to logging and fragmentation of natural forests, particularly late-successional species
Many temperate forests require periodic fires to maintain successional processes
Large carnivores are highly sensitive to human activities, including low intensity hunting
This habitat is highly sensitive to logging and fragmentation
Introduced, exotic species can have significant impacts on natural forest communities