Tropical Dry Forest

K. Wettstein

                                                            

Temperature

•Temperatures are high all year: the average temperature is above 24°C

•Because of its proximity to the coast, fluctuations in annual temperatures are only 10-15° C

•Frost and temperatures below freezing are rare

•Temps. have been recorded as low as 3°C and as high as 31°C

• The air changes from moist due to inter-tropical region mixtures in the summer to the dry air because of a subtropical weather front during the winter

Imperative Information

Solar Isolation

• Seasonal alternation

•A well defined dry season, but a short wet season in comparison to a tropical rain forest

•The dry season typically lasts from June through August

Precipitation

•The dry season is far longer than the brief period of rainfall

•There is no set amount of rain, it depends on the area

•Annual rainfall is anywhere from 10-20 cm to 1000 – 1500 cm per year depending on the specific tropical dry forest

•There is decreasing summer precipitation

Limiting Factors

•Its well defined dry season limits plant growth and the activity of animals

•A large soil-water shortage occurs, especially severe during the hottest time prior to the rains

Species DiversityPlant Life

• Most of the trees and shrubs found in this type of habitat are deciduous, losing their leaves at beginning of the dry season

– Leaves shed in dry season to conserve soil moisture.

• Up to 40 tree species in small forests

• Dry forests consist of trees, shrubs, and undergrowth of different heights which form a canopy

• Lotus, ironwood, and acacias

• Columnar, jumping cholla and barrel cactus

• More light penetration and more understory vegetation than a tropical rain forest

Animal Life• Tasmanian devil • American alligator• Merriam's Kangaroo rat • Ants• Lizards• Shrews • Coyotes • Kit and gray foxes• Ringtails• Raccoons• Skunks • Badger • Bobcat • Mountain lion • Ocelot

 

Food Chain

Energy from sun

First tropic level: Producers

Second tropic level: Primary consumers

Third tropic level: Secondary consumers

Fourth tropic level: Tertiary consumers

Decomposers

heatheat heat heat

heat

Interesting Facts

It may come as a surprise that for over 75% of the tropics, annual drought is a way of life.

Dry tropical forests are also heavily logged, and are nearly vanished in Indonesia.

There is really no actual distinction between this zone and the tropical rain forest. Because the length of the dry season varies tremendously throughout the tropics, one biome gradually changes into the other over hundreds of miles. Wetter or drier soils sometimes produce pockets of tropical dry forest within a tropical rain forest.

Climate / Seasons: Tropical dry forests have a seasonal climate, alternating between a wet and dry season. However, the dry season is often longer than the wet season, lasting over five months every year. Temperature:

The annual mean temperature is approximately 81ºF, or around 27ºC. However, in the dry season, this may increase to 99ºF, or 37ºC.

Geography: Located from 10º to 25º N and S.

Precipitation: The annual rainfall is usually around 150-200 cm.

Soil: The soil in this area is richer with nutrients, but is more vulnerable to erosion.

Limiting Factors of the Biome: The fact that the dry season lasts longer than the wet season, as well as the soil’s high susceptibility to erosion, limits the growth of certain plant life. This, in turn, will limit the biome’s ability to sustain animal life.

Sunlight: Trees are not as close to each other as in a rain forest, therefore allowing more sunlight to reach the forest floor.

The majority of the biome’s fauna is deciduous, meaning these plants shed their leaves at the onset of the dry season in order to prevent excess water loss. Other species of plants store water in their fleshy leaves or stems, or simply have thick waxy skins, such as cacti.

Types of plants: deciduous shrubs, cacti, deciduous trees, and legumes.

Animals in the tropical dry forest have adapted to survive in the arid, dry seasons. Many animals are nocturnal, gathering their food in the cooler night, conserving water. Insects can readily survive in these conditions, and provide a source of food for larger animals. Types of animals: desert deer, cactus and pocket mice,

wood and kangaroo rats, lizards, gophers, rabbits, coyotes, foxes, raccoons, badgers, and bobcats.

Decomposers such as mold and fungi work during the brief wet season to break down waste into nutrients.

Deciduous shrubs Ants

Sun

Jackrabbit Coyote

Fungus

Since dry forest is suitable for agriculture, much of it has been burned to make way for farmland.

Tropical dry forests make up the majority of tropical forests on the earth. Even though they are more endangered than rainforests in some areas, public awareness is still at a minimal.

The high productivity during the wet season, as well as the relief from rain during the dry season makes this a favorable area for humans to clear in order to be developed for agricultural needs.