Commonwealth of the Northern Mariana Island’s forest resources: forest inventory and analysis, 2015
| Authors: | Julian Dendy, Olaf Kuegler, Ashley Lehman, Victor D. Guerrero |
| Year: | 2024 |
| Type: | General Technical Report |
| Station: | Pacific Northwest Research Station |
| DOI: | https://doi.org/10.2737/pnw-gtr-1028 |
| Source: | Gen. Tech. Rep. PNW-GTR-1028. Portland, OR: U.S. Department of Agriculture, Forest Service, Pacific Northwest Research Station. 38 p. |
Abstract
In 2015, the U.S. Department of Agriculture, Forest Service, Forest Inventory and Analysis program collected forest and tree measurements from 37 plots among three forest communities on the islands of Rota, Saipan, and Tinian in the Commonwealth of the Northern Mariana Islands (CNMI). A total of 36 tree species and 132 dominant vascular plant species were recorded, including 28 invasive species. Invasive plant species covered most of the forest area, and 9 of the top 20 most dominant nontree plant species were invasive. The small tree Leucaena leucocephala (tångantångan), comprising by far the largest invasive component in CNMI, made up a substantial percentage of damaged trees and was the only tree species removed by people between inventories (2004–2015). Tree damages from coconut rhinoceros beetles and forest disturbance from wild pigs were not observed.
Rota had the least disturbed forests among inventoried islands, with the most native forest—about two-thirds of the total forest area was undisturbed. About 60 percent of the forest area on Saipan and 100 percent of the forest area on Tinian were disturbed. Tree disease was the most prevalent disturbance and damage type in 2015. Vegetation suppression due to vines occurred in about one-third of the total forest area. Disturbance from livestock affected about 10 percent of the total forest area (mostly on Tinian). This was roughly the same situation as in the 2004 inventory. In both inventories, tree stem density was about 1,400 stems per acre, and forests were dominated by small trees less than 3 inches in diameter at breast height (DBH). About 11 percent of these trees grew into the 3.0–4.9-inch DBH size class between inventories, and although the mean DBH, tree height, and stem density did not change significantly between 2004 and 2015 in CNMI forests, there was a significant increase in mean basal area per acre.