Effect of long-term burn-pruning on the flora in a lowbush blueberry (Vaccinium angustifolium Ait.) stand

Abstract

. 2008. Effect of long-term burn-pruning on the flora in a lowbush blueberry (Vaccinium angustifolium Ait.) stand. Can. J. Plant Sci. 88: 351Á362. The effect of burn-pruning on the flora in a natural stand of lowbush blueberry was studied over a 24-yr period in Newfoundland and Labrador, Canada. Treatments were: not burned and burn-pruned every 2nd, 3rd, or 4th year. A vegetative survey was conducted before burning and periodically in succeeding years. Following statistical analyses, species were grouped according to their response to burning, as follows: those not significantly affected; those eliminated or whose frequency of occurrence was reduced; and those whose occurrence was increased. Initially, burning virtually eliminated Juniperus communis var. depressa, Empetrum nigrum, Cladina rangiferina, Lycopodium clavatum and Pleurozium schreberi, reduced the frequency of occurrence of nine species by 6 to 69%, and increased 13 others by 1 to 2050%. With burning, Polytrichum commune and Fragaria virginiana ssp. glauca, in particular, increased very early in the study to become two of the most prevalent species. Also, except for some initial effects of burning, the lowbush blueberry and some initially prevalent species (Festuca filiformis, Maianthemum canadense, Danthonia spicata, Cornus canadensis and Luzula multiflora var. acadiensis) remained among the most dominant species. Of the species studied, only seven each of those increased or decreased by burning were affected by the burnpruning cycle. In both groups, the greatest increases or decreases in the frequency of occurrence were obtained with the 2-yr burn-pruning cycle. Ils ont groupe´les espe`ces comme suit, selon leur re´action au traitement en recourant a`des me´thodes d'analyse statistique : plantes peu touche´es; plantes supprime´es ou moins abondantes; plantes plus abondantes. Au de´part, les bruˆlis ont virtuellement e´limine´Juniperus communis var. depressa, Empetrum nigrum, Cladina rangiferina, Lycopodium clavatum et Pleurozium schreberi, diminue´la fre´quence de neuf autres espe`ces de 6 a`69 % et accru l'abondance de 13 autres de 1 a`2 050 %. Apre`s les bruˆlis, Polytrichum commune et Fragaria virginiana ssp. glauca ont vu leur population augmenter tre`s rapidement au de´but de l'e´tude pour devenir deux des espe`ces les plus courantes. Outre certains effets initiaux attribuables aux bruˆlis, le bleuet nain et quelques espe`ces de´ja`abondantes (Festuca filiformis, Maianthemum canadense, Danthonia spicata, Cornus canadensis et Luzula multiflora var. acadiensis) ont continue´de figurer parmi les espe`ces dominantes. Sur les espe`ces examine´es, sept seulement des groupes dont les bruˆlis accroissaient ou re´duisaient la population ont e´te´affecte´es par le cycle d'e´lagage et de bruˆlis. Dans ces deux groupes, la plus forte hausse ou baisse d'abondance se produit avec le cycle d'e´lagage-bruˆlis de deux ans.

The role of the seed bank in recovery of temperate heath and blanket bog following wildfires

“…However, two previous studies of shrubland and forest fires found no recovery of E. nigrum over periods of 4–5 yr post‐burning (Penney et al. ; Hekkala et al. ).…”

Determination of Festuca filiformis seedbank characteristics, seedling emergence and herbicide susceptibility to aid management in lowbush blueberry (Vaccinium angustifolium)

“…Certain species of predatory ground beetles consume F. filiformis seeds in lowbush blueberry fields (Cutler et al ., ), and management practices that support the presence of these insects may therefore contribute to significant F. filiformis seed losses to predation. Festuca filiformis seeds are also susceptible to heat (White & Boyd, ), and although burn pruning does not consistently reduce F. filiformis density (Penney et al ., ), the location of most seeds on the soil surface suggests that burn pruning may be an effective method of seedbank management for these grasses. It is unclear why seedling density, but not seed density, was affected by site, although viability of F. filiformis seeds is variable (White & Kumar, ) and the difference in seedling density at each site may simply be reflective of this characteristic of seeds of this weed in lowbush blueberry fields.…”

The Biology of Canadian Weeds. 149. Rumex acetosella L.

“…Penney et al (2008) reported a large increase in R. acetosella following burning of wild blueberry fields in Newfoundland. However, subsequent burnings reduced the occurrence of R. acetosella, presumably due to destruction of seed in the soil seed bank.…”

“…In New Brunswick, it is associated with understory plant communities of jack pine mixed hardwood forests (MacLean and Wein 1977), and as a common weed of cereal crops (Thomas et al 1994). Rumex acetosella is also commonly associated with lowbush blueberry fields in New Brunswick, Nova Scotia (McCully et al 1991;Jensen and Yarborough 2004), and Newfoundland (Penney et al 2008). …”