Identifying Grassland

2: Identifying Grasslands: Unimproved vs. Semi-Improved Meadows

Learn how to tell the difference between unimproved and semi-improved grasslands. Explore indicator species, diversity levels, and management histories.

In the first thread, we established that human management is the "heartbeat" of a grassland. However, not all management is equal. To understand the biodiversity of the Sidmouth area, we must distinguish between Unimproved (Semi-natural) and Semi-improved grasslands.

The Key Difference: Management History

The primary distinction lies in how much "modern intensive" farming the land has seen.

Unimproved Grassland: This habitat is often the result of thousands of years of traditional forest clearance and grazing. It has avoided modern chemical fertilizers, herbicides, and intensive drainage.
Semi-improved Grassland: This is a "transition" category. These areas were once species-rich but have been modified by partial improvements, such as the application of slurry or artificial fertilisers.

At a Glance: How to Spot the Difference

When you are out in the field, look for these three key indicators:

1. Species Diversity (The "Count" Test)

Unimproved: Features very high species diversity. For example, ancient chalk grasslands can host up to 40 species per square meter. A high plant count usually indicates an older, undisturbed site.
Semi-improved: The range of species is noticeably lower and feels less "natural" than the surrounding unimproved sites.

2. Indicator Species

Unimproved: Look for "specialist" wildflowers that match the soil type.
- Neutral Soils: Snake’s-head fritillary or Green-winged orchids.
- Calcareous Soils: Cowslip, Kidney vetch, or various rare orchids.
- Other: Abundant mosses are often a good sign.
Semi-improved: These sites have a more restricted list of species. Because agricultural "improvement" tends to neutralize the soil's character, it can be harder to tell if the land was originally acid or calcareous.

3. The "Lushness" Factor

Unimproved: Supports a very low percentage of agricultural grasses.
Semi-improved: If the field looks bright green and lush, it is likely improved. However, if it lacks the heavy dominance (over 50%) of agricultural species like Perennial Ryegrass (Lolium perenne) or White Clover (Trifolium repens), it is likely in the "semi-improved" category.

Why the Distinction Matters

Understanding these categories helps conservationists identify which areas need themost protection.

Unimproved sites are critical reservoirs of ancient biodiversity that cannot be easily replaced.
Semi-improved sites still hold conservation value but represent a landscape in transition.

Without ongoing traditional management like mowing or grazing, both types would eventually disappear, reverting to scrub and woodland within 50 years.

Before you go

Activity: The 1-Metre Meadow Survey

Goal: To determine if a local patch of grassland is Unimproved, Semi-Improved, or Improved using the indicators learned in the articles.

What You’ll Need:

A notebook and pen.
A 1-metre length of string (tied in a loop) or four sticks to mark out a square (a "quadrat").
A basic wildflower ID guide (or a nature app like Seek or iNaturalist).

Step 1: The "Lushness" Test (Initial Scan)

Before you even put your string down, look at the field as a whole.

Is the field a uniform, "neon" bright green? (Likely Improved).
Is the color patchy, with different shades of green, brown, and yellow? (Likely Semi-natural/Unimproved).

Step 2: Set Your Plot

Find a representative spot in the field—don't just pick the prettiest flower! Lay your string loop on the ground to create a square.

Step 3: The Diversity Count

Look closely inside your square. Don't worry about names yet—just look at the shapes of the leaves.

Count the "Types": How many different shapes of plants do you see? (e.g., thin grass blades, clover-like leaves, jagged "toothed" leaves, fuzzy leaves).
The Magic Number: * 1–5 types: Likely Improved (Agricultural).
- 6–15 types: Likely Semi-Improved.
- 15+ types: You may have found a rare Unimproved site!