Model Answer
0 min readIntroduction
A herbarium is a collection of preserved plant specimens, used for taxonomic studies, floristic surveys, and understanding plant diversity. It serves as a vital resource for botanical research and conservation. The process of creating and maintaining a herbarium involves a series of carefully executed steps, ensuring the specimens are accurately identified, properly preserved, and readily accessible for scientific study. Effective herbarium management is crucial for maintaining a reliable record of plant life and supporting biodiversity research.
Procedure of Herbarium
The procedure for establishing and maintaining a herbarium can be broadly divided into the following stages:
1. Collection of Plant Material
- Selection: Representative specimens are collected, ideally including all reproductive parts (flowers, fruits, seeds) for accurate identification.
- Numbering: Each specimen is assigned a unique collection number, crucial for tracking and referencing.
- Field Data: Detailed field notes are recorded, including location (GPS coordinates), habitat, date, collector’s name, and any relevant observations (e.g., plant colour, abundance).
2. Processing of Specimens
- Pressing: Specimens are carefully pressed between blotters and corrugated cardboard to flatten them.
- Drying: Pressed specimens are dried using heat (e.g., using a plant dryer or by air-drying with silica gel) to prevent decay.
- Poisoning: Dried specimens are treated with a fungicide/insecticide (e.g., mercuric chloride, arsenic pentoxide – though these are increasingly avoided due to toxicity, replaced by naphthalene flakes or thymol) to prevent fungal growth and insect damage.
- Mounting: Dried and poisoned specimens are mounted on herbarium sheets (typically acid-free card) using strips of archival-quality paper or glue.
3. Data Recording and Labelling
- Herbarium Sheet Label: A label is attached to each sheet containing essential information: plant name (scientific and local), collection number, location, date, collector, habitat, and any other relevant notes.
- Database Entry: Specimen data is entered into a computerized database for easy searching and retrieval.
Maintenance of Herbarium
Maintaining a herbarium requires ongoing effort to ensure the long-term preservation of the collection.
1. Storage Conditions
- Temperature and Humidity Control: Herbarium specimens are stored in a cool, dry, and well-ventilated environment to minimize fungal growth and insect activity. Ideal temperature is 15-20°C and relative humidity below 65%.
- Protection from Light: Specimens are protected from direct sunlight to prevent fading and degradation.
- Insect Pest Management: Regular monitoring for insect pests and implementation of appropriate control measures (e.g., naphthalene flakes, fumigation) are essential.
2. Regular Inspection and Repair
- Sheet Inspection: Herbarium sheets are regularly inspected for signs of damage (e.g., insect damage, fungal growth, brittle specimens).
- Repair and Remounting: Damaged specimens are repaired or remounted on new sheets as needed.
3. Database Management
- Data Updates: The herbarium database is regularly updated with new information, such as taxonomic revisions and additional collection data.
- Digitization: Increasingly, herbarium specimens are being digitized (photographed and data entered online) to make them more accessible to researchers worldwide.
Conclusion
The procedure and maintenance of a herbarium are critical for preserving plant biodiversity and supporting botanical research. From careful specimen collection and processing to long-term storage and database management, each step plays a vital role in ensuring the integrity and accessibility of these invaluable resources. Modern herbarium practices increasingly emphasize digitization and sustainable preservation methods to meet the evolving needs of the scientific community and contribute to conservation efforts.
Answer Length
This is a comprehensive model answer for learning purposes and may exceed the word limit. In the exam, always adhere to the prescribed word count.