Field inventory of seedling germination and establishment
Erdozain, M.1; Raimbault, A.1; de-Miguel, S.2,1
1Forest Science and Technology Centre of Catalonia
2Department of Agricultural and Forest Sciences and Engineering, University of Lleida, Lleida, Spain
Last updated: 24/09/2026
Recommended citation:
Erdozain M., Raimbault A., de-Miguel S. 2026. Field inventory of seedling germination and establishment. In: Pere Casals, Davide Ascoli, Lena Vilà-Vilardell, Imma Oliveras, Madoka Krick (eds.) 2026. Methods handbook for characterizing fire use behavior, assessing fire effects, and monitoring soil and vegetation responses at the stand level. FIRE-ADAPT project (number 101086416), deliverable D1.1
Indicator
Ecosystem responses: Vegetation responses
Brief introduction
Post-fire forest resilience is now threatened by climate change, which influences fire activity (Westerling et al., 2006) and increases drought stress on post-fire seedlings (Johnstone et al., 2010; Williams et al., 2012). There is therefore growing uncertainty regarding how shifting climate and disturbance regimes will affect forest regeneration success rates (McDowell et al., 2020; Rammer et al., 2021). Post-fire forest regeneration is primarily governed by two processes: seed dispersal and seedling establishment in recently burned areas (Harvey et al., 2016). The early developmental stages of seedlings (germination, survival, and growth) represent the most critical steps in a tree’s life (Harper 1977; Matney & Hodges 1991). These stages are particularly sensitive to climatic conditions as well as local site characteristics, such as topographic setting and interspecific competition (Harvey et al., 2016). The present protocol aims to monitor post-fire forest regeneration by studying seedling survival through a non-destructive measurement approach, to assess the influence of environmental conditions on seedling establishment and development.
Method specifications
Method type
Soft
Hard
Method timing
Before
fire
During
fire
After fire
(short-term)
After fire
(mid-term)
After fire
(long-term)
Field skills
Low
Medium
Hard
Lab skills
Low
Medium
Hard
Material cost
Low
Medium
Hard
Time cost
Low
Medium
Hard
Calculation expertise
Low
Medium
Hard
Equipment
- Notebook
- Caliper
- UV-resistant colored cable ties (1 colour per each monitoring year)
- Ruler
Experimental design
A relevant approach to assess the effects of forest fires on forest regeneration is to implement long-term monitoring using permanent plots. The number and spatial distribution of plots will vary depending on available resources and the characteristics of the fire (size, spatial extent, etc.). Ideally, plots should be established across areas burned at different severity levels, with at least three permanent plots per severity class, although this number may be adjusted according to available resources. Additionally, at least three control plots should be established in unburned areas that are as comparable as possible to the burned areas in terms of vegetation composition, soil properties, and topographic characteristics. Plots of 100 m² (10 × 10 m) provide a representative sample of natural regeneration while remaining practical to survey (Erdozain et al., 2023). Plots should be surveyed annually at the same time (e.g., spring) to examine the development and fate of seedlings, ideally for five years.
Methodology
- Survey each plot following a zigzag approach looking for seedlings.
- Label each seedling with a unique identifier recording the year of planting or germination with a unique identifier. UV-resistant colored cable ties are an easy and effective way to keep track of the germination/planting year, using a different colour for each planting/germination year.
- For each seedling, the height of the main stem will be measured using a graduated ruler, while the diameter will be recorded using a calliper at the stem-base. These measurements will be systematically taken at each survey visit at the same reference point1. Therefore, for each seedling, a fixed reference point must be determined on the main stem to ensure that diameter is consistently measured over time.
1 It should be noted that a seedling that appears dead may continue its development by producing a new secondary stem distinct from the main stem. During each survey visit, particular attention must therefore be paid to the entire seedling to avoid underestimating survival rates.
Calculations
The average number of seedlings per hectare as well as the primary and secondary growth increments can be calculated for each year and compared across burned classes
Relation with other methods
NA
Further information
Erdozain, M., Bonet, J. A., Martínez de Aragón, J., & de-Miguel, S. (2023). Forest thinning and climate interactions driving early-stage regeneration dynamics of maritime pine in Mediterranean areas. Forest Ecology and Management, 539, 121036.
Harper, J.L., 1977. Population biology of plants. Academic Press, London, UK 1977, 892.
Harvey, B. J., Donato, D. C., & Turner, M. G. (2016). High and dry: Post‐fire tree seedling establishment in subalpine forests decreases with post‐fire drought and large stand‐replacing burn patches. Global Ecology and Biogeography, 25(6), 655-669.
Johnstone, J. F., McIntire, E. J., Pedersen, E. J., King, G., & Pisaric, M. J. (2010). A sensitive slope: estimating landscape patterns of forest resilience in a changing climate. Ecosphere, 1(6), 1-21.
Matney, T.G., Hodges, J.D., 1991. Evaluating Regeneration Success. In: Duryea, M.L., Dougherty, P.M. (Eds.), Forest Regeneration Manual. Springer, Dordrecht, The, Netherlands, pp. 321–331.
McDowell, N.G., Allen, C.D., Anderson-Teixeira, K., Aukema, B.H., Bond-Lamberty, B., Chini, L., Clark, J.S., Dietze, M., Grossiord, C., Hanbury-Brown, A., Hurtt, G.C., Jackson, R.B., Johnson, D.J., Kueppers, L., Lichstein, J.W., Ogle, K., Poulter, B., Pugh, T.A.M., Seidl, R., Xu, C., 2020. Pervasive shifts in forest dynamics in a changing world. Science 368 (6494), eaaz9463.
Rammer, W., Braziunas, K. H., Hansen, W. D., Ratajczak, Z., Westerling, A. L., Turner, M. G., & Seidl, R. (2021). Widespread regeneration failure in forests of Greater Yellowstone under scenarios of future climate and fire. Global Change Biology, 27(18), 4339-4351.
Westerling, A. L., Hidalgo, H. G., Cayan, D. R., & Swetnam, T. W. (2006). Warming and earlier spring increasewestern US forest wildfire activity. science, 313(5789), 940-943.
Williams, A.P., Allen, C.D., Macalady, A.K., Griffin, D., Woodhouse, C.A., Meko, D.M., Swetnam, T.W., Rauscher, S.A., Seager, R., Grissino-Mayer, H.D., Dean, J.S., Cook, E.R., Gangodagamage, C., Cai, M. & McDowell, N.G. (2012) Temperature as a potent driver of regional forest drought stress and tree mortality. Nature Climate Change, 3, 292–297.