On April 1, the Uttarakhand High Court stayed the felling of oak trees in Mussoorie for construction by the Municipal Council.In a PIL petition, the petitioner had cited a Right to Information application filed with the Divisional Forest Officer of Mussoorie to seek confirmation on whether the forest department had provided a no-objection certificate (NOC) to the Municipal Council to fell the trees. The department had replied that no NOC was sought.The petition claimed that the construction appears to be undertaken for extraneous considerations, including facilitating adjoining private establishments such as hotels.So, what are these trees and why do they matter to the region’s ecology? Here’s what to know.Oak belongs to the genus Quercus in the Fagaceae family and holds immense social and ecological importance in the Indian Himalayan regions. In these regions, 35 species of oaks have been reported between 800 and 3,000 metres above sea level. In the western Himalaya, five oaks have been reported, and the species are providers of numerous ecosystem services such as conservation of soil, water, native flora and fauna, and serve as a lifeline for the local communities. Oaks found in Uttarakhand are Banj oak, Moru oak, Kharsu oak, Rianj oak, and Phaliath oak. Oak forests assist watershed protection by promoting the recharge of springs.Also read | Decades-old ‘simmering’ fires, termites, invasive weeds: Why forests in 3 Himachal districts are in critical declineOak forests support a remarkably diverse web of life. Their trees host lichens, bryophytes, pteridophytes (all three being moss-like plants), orchids, and other flowering plants, creating layered microhabitats.Story continues below this adBird data from the Cornell Lab of Ornithology’s eBird platform shows high species richness across Himalayan districts with oak cover: about 440 species in Tehri Garhwal, 391 in Rudraprayag, 491 in Almora, 311 in Bageshwar, 383 in Chamoli, and 366 in Champawat. Insects are equally present: a 2022 study from Ranichauri (Tehri Garhwal) recorded 24 butterfly species in Banj oak forests alone.These ecosystems also sustain a wide range of animals. Birds and mammals such as jays, Himalayan langurs, red giant flying squirrels, and Asiatic black bears feed on oak leaves and acorns, often caching them for leaner periods. The forests are also teeming with snails, slugs, millipedes, woodlice, insects, and countless microorganisms — including bacteria, fungi and algae — making oak forests hubs of biodiversity at every level.Degradation of oak trees, and impactA December 2025 paper titled “Degradation of Oak Forests in the Himalaya: Impacts on Diversity Carbon Stock, and Regeneration”, published in the Trees, Forests, and People journal, pegged the degradation of forests in the Indian Himalayan regions at a rate of 0.36 sq km per year due to both natural calamities as well as anthropogenic disturbances, including developmental activities.“In the Himalayan region, the chronic form of disturbance is that in which people remove only a small fraction of forest biomass in the form of grazing, lopping, surface burning, and litter removal at a given time. However, the process continues relentlessly year after year. The problem with the chronic form of forest disturbance is that the plants or ecosystem often do not get enough time to recover adequately because the human onslaught never stops,” it said.Story continues below this adAlso read | Tree Talk: The mighty oaks of ChandigarhAs the canopy cover gets reduced, this has a direct effect on seed production of any species, affecting the regeneration through changes in the understory vegetation. Moreover, several changes are set in action due to excessive lopping, grazing, and fuel and fodder consumption.In Uttarakhand, oak is used as fuel wood and fodder by locals from the forests near their settlements. In the area where the aforementioned study took place, the average fuel wood collection ranged between 25 and 30 kg per household per day (kg/hh/day), as the oak species are the most preferred fuel species due to their sustained burning and for the production of better heat. The fodder collection value ranged between 15 and 22 kg/hh/day.According to a 2018 piece by academic Anuradha Thakur for the International Forestry Students’ Association, other causes of failure in regeneration include increased incidences of fire. Also, oak forests are undergoing rapid transformation due to invasion by alien invasive species, such as Eupatorium adenophorum, Lantana camara, and others, such as chir pine. The former outcompetes native flora, altering forest structure and reducing biodiversity, while the replacement by pine has become a common phenomenon.Also, chir pine trees are highly inflammable and increase the incidence of forest fires. When oaks catch fire, the damaged stems are highly susceptible to pathogens, which weaken the tree and result in wind throw and breakage.