Once covering over 5000 hectares now just a fraction remains. This is Almorah Rock Forest. It is also known as Epsom Rock Forest. This unique lava rock forest sits on Maungawhau / Mount Eden’s northeastern slope. Here in Auckland New Zealand it stands as one of the few remaining lava rock forest patches.
Almorah Rock Forest formed on lava fields around Maungawhau / Mount Eden. These fields emerged 28000 years ago. Magma moved through Maungawhau / Mount Eden’s scoria base. This caused lava flows down the volcano’s slope. The magma then solidified into basalt rock deposits.
Originally the Almorah Rock Forest spanned 5000 hectares. Today it’s reduced to a 3.2-hectare pocket. This includes three small reserves and private properties. Auckland Council designates this area as a Significant Ecological Area. The forest floor contains limited soil. Leaf litter accumulates between boulders. This allows plants to germinate.
Almorah Rock Forest teems with both native and introduced species. A 1999 study found 40% of Withiel Reserve’s plants were native. Large native canopy trees thrive here. These include Mangeao and Titoki. You can also find Puriri and Kohe Kohe. Akapuka trees also grow here. Sub-canopy species include Mahoe and Houpara. Native understory plants feature Kawa Kawa and Karamu. Various ferns carpet the forest floor. Look for King Ferns. The rare Sickle Fern has also regenerated here.
Introduced weeds also exist in Almorah Rock Forest. Climbing Asparagus and Japanese Hill Cherry are present. In 2016 Auckland Council and the Auckland Motorway Alliance removed 40 invasive tree privets. This happened on the forest’s northeastern edge.
Almorah Rock Forests provide habitat for native birds. Kereru, Piwakawaka / Fantail and Tui flourish here. Kaka and Tauhou / Silvereye have also been spotted.
Introduced mammals like rodents and possums pose a threat. Possums eat indigenous plants and attack native birds. Rats eat bird eggs, chicks and plant seeds. This negatively affects forest regeneration. Urban Ark supports community groups. The Maungawhau Ecological Halo helps reduce mammalian predators. They use backyard traps around the rock forest and Maungawhau.
Much of Auckland’s native forest was likely burned by Maori settlers. This began in the 13th century. This likely included parts of Almorah Rock Forest. It was near a pa site on Maungawhau / Mount Eden. Various iwi occupied the pa. These included Nga Oho. Later Huakaiwaka occupied it. Warfare left the pa vacant in the 18th century.
Europeans sought the Almorah Rock Forest area for residences after 1840. Rockwood House was built near the rock forest in 1865. Alfred Sharpe painted the house and forest in 1876. Subdivision continued until the 1980s. Then ecological and architectural concerns halted it.
In 1948 Algernon Thomas’s descendants gifted a 0.7-hectare block to the city. This land was within the Almorah Rock Forest. Thomas was a natural history scholar. He became a professor at Auckland University College in 1883. Thomas advocated for native bird protection in 1886. This block is now Withiel Thomas Reserve. The public can access it.
In 2001 a 1.4-hectare site was placed under the Department of Conservation. This followed a public controversy. A developer wanted to build dwellings. The decision followed negotiations.
In 2014 a landowner was fined $16250. They felled vegetation and removed rock. This breached the Auckland Unitary Plan.
So as you wander through the Almorah Rock Forest think about its long history. Consider the efforts to preserve this unique ecosystem. Appreciate the rare beauty around you.