The Tongan tropical moist forests cover the Tonga archipelago of some 170 islands together with nearby Niue, a Polynesian ecoregion in the Oceania realm scattered across the southwestern Pacific. Below about 500 meters, tropical lowland rain forest predominates, with an evergreen canopy of trees such as Diospyros, Calophyllum neo-ebudicum, Ficus obliqua, Rhus taitensis, and Alphitonia, while coastal stands of Casuarina equisetifolia and mangroves of Bruguiera gymnorhiza fringe the shore. The climate is warm and wet year-round, with mean temperatures ranging from roughly 20 to 30 degrees Celsius across the seasons and average annual rainfall of 2000 millimeters or more, heavier on windward slopes. The ecoregion holds around 419 native species of vascular plants with about 3 percent endemism, and the colorful Tongan whistler serves as its flagship bird; the forests are classed as critically endangered after thousands of years of settlement and subsistence agriculture cleared much of the original habitat. For gardeners in warm, frost-free climates, native genera here such as Calophyllum, Ficus, and the salt-tolerant Casuarina equisetifolia are familiar ornamental and shade trees.
Marker placed inside the RESOLVE 2017 polygon at 19.0°S, 169.9°W.
Climate snapshot for this ecoregion
°C
°F
Current zone range (2011–2040)
13b
Plotwright
CHELSA-derived typical winter month at this ecoregion's bbox grid.
Projected (2041–2070)
13b
Plotwright
Where the CHELSA models say the typical winter month is heading.
Average warming this ecoregion is on track for: +2.2°F by mid-century. SSP3-7.0 (current trajectory) · CHELSA v2.1 bio06 sampled across 10 of 10 points within this ecoregion's bounding box.
At a glance
Dominant biome
Tropical & Subtropical Moist Broadleaf Forests
Realm
Oceania
Approximate area
363 sq mi
Conservation tier
Nature Imperiled (Dinerstein NNH 4)
About the tropical & subtropical moist broadleaf forests biome
Warm, wet, highly productive forests — including tropical rainforests — with closed canopies, near year-round growing seasons, and the richest terrestrial biodiversity on Earth. Low seasonality and high rainfall sustain dense, layered vegetation from canopy to forest floor.
Catalog plants suited to this ecoregion
No catalog plants intersect this ecoregion's zone range. As the catalog grows to cover this region's climate band, suggestions will surface here.
Collections for this ecoregion
No curated collection's plants all fit this ecoregion's zone range. We surface a collection only when every member would grow here — partial fits get filtered out rather than mislead. As the catalog and the curated set both grow, this section will fill in.
Related ecoregions
Other tropical & subtropical moist broadleaf forests ecoregions to explore: