New Guinea Highlands

The New Guinea Highlands, also called the Central Range, is a massive chain of mountains.

It runs east-to-west across the island of New Guinea. This island is divided between Indonesia in the west and Papua New Guinea in the east. The range includes Puncak Jaya, which is the highest peak in Oceania. This mountain is located in Indonesia. The highlands are a vital part of the island's geography and ecology. They create many different environments for plants and animals. The mountains also serve as the source for major rivers like the Sepik and the Fly.

The mountains formed through intense geological activity. The Australian Plate is colliding with plates to the northeast. This movement causes the mountains to rise and creates earthquakes. The surface of the highlands consists of metamorphic and intrusive igneous rocks. Metamorphic rocks are formed when existing rocks change due to heat and pressure. These rocks were once ocean sediments from the Cretaceous and Eocene periods. They were uplifted and folded between the Eocene and early Miocene periods. Some parts of the range also feature Pleistocene stratovolcanoes. These include Mount Hagen and Mount Giluwe.

The highlands are divided into several distinct mountain groups. Moving from east to west, you find the Central and Eastern Highlands of Papua New Guinea. This includes the Owen Stanley Range, where Mount Victoria reaches 4,038 metres. Next are the Albert Victor Mountains and the Sir Arthur Gordon Range. The Bismarck Range follows, featuring the extinct volcano Mount Wilhelm at 4,509 metres. Further west are the Star Mountains on the border of Papua New Guinea and Indonesia. Finally, the Maoke Mountains, or Snow Range, sit in Indonesia. This range contains Puncak Jaya, which stands at 4,884 metres.

Human history in these mountains is very old. Artifacts in the Ivane Valley suggest settlement began about 50,000 years ago. Early inhabitants were nomadic foragers. Around 10,000 years ago, they developed advanced agricultural societies. The introduction of the sweet potato changed their economies significantly. Because pigs could eat sweet potatoes without cooking, people could raise more pigs. These pigs became a central part of trade between different groups.

Western explorers like Mick Leahy and Richard Archbold arrived in the 1930s. They discovered that over a million people lived in the highland valleys.

Life in the highlands is shaped by the tropical climate and high elevation. The lowlands are humid and covered in rainforest. However, the higher mountain slopes are much cooler. The environment is split into two main ecoregions. The first is the montane rain forest, found between 1,000 and 3,000 metres. The lower montane forest has broadleaf evergreen trees. The upper montane forest is dominated by moss-covered Nothofagus trees.

Above 3,000 metres, the forest changes into sub-alpine habitats. These areas include alpine meadows, bogs, and shrubby heaths.

The highlands are famous for their endemic species. Endemic species are those found nowhere else on Earth. The mountains host many unique animals, including tree-kangaroos and birds of paradise. Mount Giluwe is a major area for watching birds of paradise.

Many mammals are also unique to these ranges. Out of 90 mammals on the island, 44 are endemic. Some, like the Bulmer's fruit bat, are critically endangered. The high alpine zones above 4,000 metres host specific animals like the glacier rat. These high-altitude creatures live in a world of cushion herbs and lichens.

Economic activity plays a large role in the region today. Many people live in agricultural communities within the intermountain valleys. Towns like Mount Hagen and Goroka serve as important urban centers. The Highlands Highway connects many of these settlements. Mining is also a major industry in the area. The Porgera Gold Mine is located in the Enga Province. Additionally, oil has been extracted from near Lake Kutubu since 1992.

While these industries provide resources, they can also cause friction with indigenous groups.

Conservation is an important part of managing the highlands. Much of the land is protected to save its unique biology. Lorentz National Park is located in the Indonesian highlands. It is the largest protected area in Southeast Asia. About 20% of the montane rain forest ecoregion is contained within protected areas. These parks help preserve the intact forests from threats like the logging industry. Protecting these mountains ensures that the unique plants, animals, and cultures of the New Guinea Highlands survive for the future.