The Historical State of the Ecosystem (Q3)

Some tropical dry forests occur on the leeward side of mountains, under the rain shadow created through orographic precipitation, where the air is neither too moist nor too dry(Rock 1914).

Metrosideros Polymorpha

There is also a wet and dry season specific to Hawaii’s tropical dry forests. The dry season lasts from April to October, while the wet season lasts from November to March.These ecological factors help explain phenomena we see throughout the vegetation of Hawaii’s tropical dry forests. For example, most trees in this ecosystem have thick barks, (about half to 1 inch thick) to help them survive the dry season, however some thin bark species exist as well (Rock 1914). Thus the leeward side of mountains provides the perfect balance of moisture for the growth of vegetation specific to Hawaii’s tropical dry forests.

Erythrina Sandwicensis

Tropical dry forests contain some of the worlds most diverse communities. About 60 percent of the tress found in Hawaii's tropical dry forests are endemic, and thus occur in no other region of the world (Rock 1913). Joseph Rock, one of the first people who studied the native landscape of Hawaii wrote, "It is in these peculiar regions that the botanical collector will find more in one day collecting than in a week or two in a wet region..." (Rock 1913). Unfortunately, they are also one of the world's most endangered ecosystems.

Hibiscus Clayi

The tropical dry forests of Hawaii have a short canopy, about 20-30 meters in height, and also contain shrubs(Gillespie 2013). Also, there are only thee types of fauna, or animals, which are indigenous to the tropical dry forests of Hawaii; those are birds, arthropods, and non-marine mollusks(Loope 2013). The following are some example of the indigenous fauna and flora of the tropical dry forests of Hawaii.

Diospyros Sandwicensis

Reynoldsia Sandwiccensis

Many of Hawaii's native arthropods are flightless; a common occurrence among species that have evolved on islands. Here we have the flightless beetle like lacewing(Francis 1990).

Ancylidae is a type of non-marine mollusk that was once indigenous to the tropical dry forests of Hawaii(Watson 2012). 

Flora Picture Sources:

"Tropical Dry Forests of the Pacific - Hawaii Species Poster." 
     Tropical Dry Forests of the Pacific - Hawaii Species 
     Poster. N.p., n.d. Web. 25 Nov. 2013.

"Tropical Dry Forests of the Pacific - Maui Species Poster." 
     Tropical Dry Forests of the Pacific - Maui Species Poster. 
     N.p., n.d. Web. 25 Nov. 2013.

Fauna Picture Sources:

Watson, L., and Dallwitz, M.J. 2005 onwards. The families of 

     British non-marine molluscs (slugs, snails and mussels). 
     Version: 4th January 2012. 

"Investigation." Backyard Insects of Tucson. N.p., n.d. Web. 27 Nov. 2013.

Sources for Writing:

Francis G. Hawaiian Terrestrial Arthropods: An Overview. 
     Thesis. Bishop Museum Occasional Papers, 1990. N.p.: 
     Bishop Museum, 1990.Hbs.bishopmuseum.org. Web. 
     22 Nov. 2013.

Gillespie, Thomas. "People and the Earth's Ecosystem." Dodd 147, Los Angeles. 29 Oct. 2013. Class Lecture.

Loope, Lloyd L. Hawaii and the Pacific Islands. Rep. U.S. Geological Survey Biological Resources Division, 19 Aug. 2013, Web. 23 Nov. 2013.

Rock JF (1913) The Indigenous Trees of the Hawaiian Islands. Reprinted in 1974 by Pacific Tropical Botanical Garden, Lawai, Kauai, Hawaii, and Charles F. Tuttle, Rutland, Vermont. 

Watson, L., and Dallwitz, M.J. 2005 onwards. The families of 

       British non-marine molluscs (slugs, snails and

        mussels).Version: 4th January 2012.