Shak (Himalayan Silver Birch)

Betula utilis (Himalayan Silver Birch)

Vernacular name: Shak, Paad (in Kinnauri)

Click here to watch a short video about this species

Click here to watch a short video about this species

The Himalayan Silver Birch (Betula utilis), locally known as “Shak” and “Paad Bothang” in Kinnauri, and “Bhojpatra” in Hindi, is native to the Western Himalayas, including regions of India, Nepal, China, Pakistan, Afghanistan, and Central Asia (Kazakhstan, Tajikistan, and Uzbekistan). Found at elevations ranging from 2,400 to 4,300 meters above sea level, Betula utilis forests provide essential habitat and food resources for various subalpine plants and animals.

Due to this crucial role, it is considered a keystone species in subalpine ecosystems. Additionally, it is the most dominant tree species in the treeline zone of the Himalayas and is regarded as a climax species (i.e., a species that dominates the final stage of ecological succession, creating a stable and self-sustaining ecosystem).

Interesting Facts about Himalayan Silver Birch:

• Betula utilis exhibits “hysteranthy”, meaning it flowers before producing any leaves. Its flowers grow in long, cylindrical inflorescences, and without foliage, the tree looks quite unique and visually striking. Several hypotheses exist to explain this peculiar trait, but the most widely accepted suggests that hysteranthy evolved in cold-climate trees to reduce water stress and to make the flowers more visible to pollinators. 

• However, this behaviour is highly sensitive to temperature and rainfall patterns. Any changes in these factors can negatively affect the tree’s health by reducing photosynthesis rates, increasing water demand, and potentially leading to slower growth, and make trees vulnerable to pests and diseases.

  
  

Uses:

• The tree’s papery bark naturally peels off and is commonly called “Paad” in Kinnauri, while “Paad Bothang” or “Shak” refers to the entire tree. In Kinnaur, the bark is traditionally used in roofing, where wooden roofs are layered with Betula bark, soil, and stone for better insulation. Locals also use the bark for timber, fodder, firewood, and in cremation rituals.

• The bark was historically used as a writing surface for traditional Indian manuscripts. Early references to this practice can be found in the works of Sushruta (3rd century CE), Kalidasa (4th century CE), and Varahamihira (6th century CE).

• Parts of the plant are also used in traditional medicine to treat cuts, burns, and open wounds. It also serves as an antiseptic and is sometimes used to treat ear infections and jaundice in some regions.

  
  

Threats:

Its life cycle events, such as bud burst, flowering, leaf initiation, and seed fall, are highly sensitive to temperature and rainfall. Global warming and climate change are altering these environmental factors, which can disrupt the tree’s growth and reproduction, potentially impacting its survival in the long term.

References

1. Singh, N., Mittal, A., Tewari, A., Shah, S., Malik, S., Khan, A. A., & Jaggi, V. (2024). Exploring water relations and phenological traits of Betula utilis (D. Don) in western Himalayan treeline ecotone. Scientific Reports, 14(1), 20853.

2. Buonaiuto, D. M., Davies, T. J., Collins, S. C., & Wolkovich, E. M. (2024). Ecological drivers of flower–leaf sequences: aridity and proxies for pollinator attraction select for flowering‐first in the American plums. New Phytologist, 242(5), 2312-2321.

3. Wani, Z. A., & Pant, S. (2021). Betula utilis D. Don: An ecologically and economically important timberline species of Himalayan Region in Jeopardy. The Botanical Review, 87(3), 377-391.

Link to instagram video: https://www.instagram.com/reel/DG9x6tcCKwD/?igsh=MWl3bzRsaXRrNmoxdw%3D%3D