Browsing and herbivore impact
Assess deer and livestock impact with WHIA v5 in Great Britain and Ireland, the regional method where one exists, the shared browsing capture elsewhere, or the nearest-neighbour damage survey for Scotland’s LISS.
- For
- Consultant foresters and deer managers
- Time
- 9 minutes to read
- Where
- Field app — Browsing impact; web — Results › Browsing impact
- Updated
On this page
Browsing decides whether a continuous-cover stand regenerates. Each method records evidence of browsing, bark stripping, fraying and ground disturbance in its own way and turns it into an impact level or a rate. Where a method’s judgement belongs to the surveyor, the app proposes a level and you decide.
Which method
| Where | Method | Layout |
|---|---|---|
| Great Britain & Ireland | WHIA, User Guide v5 provisional — seven indicators per stop, impact levels, area summary against your targets | 10 stops of ~25 m radius, ≥ 50 m apart (or WHIA Lite) |
| United Kingdom (Scotland’s LISS) | Nearest-neighbour damage survey (FC Practice Note 1, 1998) — % of trees damaged with its accuracy; the annual deer-damage evidence for Scotland’s LISS | Cluster points on a grid, 4–7 nearest trees; 20–100 clusters from the accuracy you choose |
| Switzerland | Wald und Wild (BAFU 2010) — browsing intensity per species against the Eiberle & Nigg critical rates | 30–50 permanent plots of 2 or 5 m radius |
| Bavaria | Forstliches Gutachten 2024 — statistics only; the four classes are the forester’s | Five points on a 40–100 m line, 15 nearest plants |
| France | ICE oak browsing index (fiche 14) — a trend over 4–5 years, no threshold | ≥ 50 plots of 12.5 m² |
| Austria | Wildeinflussmonitoring (WEM 2016) — game impact on regeneration, adapted to stand use provisional | The method’s sample plots |
| Sweden | Äbin — the moose browsing inventory, stand use provisional | The inventory’s circular plots |
| Poland | Instrukcja Ochrony Lasu §105 — game damage estimate provisional | The instruction’s sample plots |
| Czechia | ÚHÚL game-impact indicator — stems 10–130 cm provisional | The indicator’s plots |
| Anywhere (recommended where no regional method exists) | Shared browsing capture — leader browsing, upper third, fraying and death per young tree; rates with intervals; no thresholds | Regeneration plots |
WHIA in the field
For Republic of Ireland, United Kingdom
- Walk each stop systematically (about 25 m radius). Record ground disturbance, bark stripping and fraying of susceptible trees, broken saplings, herbivore signs and four photos.
- Tally browsing — one line per species × browsing category for basal shoots, epicormic shoots and seedlings & saplings (% of the current season’s shoot within reach removed), and for preferred and other plants.
- Read the proposed level per indicator and record your own call where you disagree (with why).
- Once per area, Stand-wide: herbivores present in the period, grazing season, and your area summary per indicator.
The nearest-neighbour survey and the shared capture
For the nearest-neighbour survey, assess the trees nearest the point — never choose them by their damage. Mixed crops: the same number of each species.
Read the result
- WHIA: each indicator’s level (No impact → Very high) against the target “not higher than …”, the overall level from your key indicator, and the guide’s long-term implications. Stops with very few examples are flagged.
- Rates (nearest-neighbour, Swiss, ICE…) come with their confidence interval; read them as trends across years.
- Fenced controls, where recorded, are compared with their unfenced twin.
- Cull records imported as a dataset show beside the time series — context, never combined with the score.
The guide’s Table 5 “best describes” judgement is proposed by fixed rules; the preferred-plant spread thresholds and some summary conventions are the app’s own. Confirm or override every level.
- It never counts deer or sets a cull; it records impact.
- Austria’s WEM, Sweden’s Äbin, Poland’s §105 and Czechia’s indicator are adapted to stand use from secondary sources — provisional.
Sources: Armstrong, Black & Holl (NatureScot) and Thompson (FLS), WHIA User Guide v5 (April 2023); Pepper (1998) FC Practice Note 1; Rüegg, Burger & Brang (2010) in BAFU Wald und Wild; StMELF (2024); ONCFS / ICE (2015) fiche 14; Schodterer (2012); Skogsstyrelsen (2026); Lasy Państwowe IOL §105; Adolt (2021).