Index of Species Information

SPECIES:  Calluna vulgaris


SPECIES: Calluna vulgaris
AUTHORSHIP AND CITATION : Matthews, Robin F. 1993. Calluna vulgaris. In: Fire Effects Information System, [Online]. U.S. Department of Agriculture, Forest Service, Rocky Mountain Research Station, Fire Sciences Laboratory (Producer). Available: []. ABBREVIATION : CALVUL SYNONYMS : NO-ENTRY SCS PLANT CODE : CAVU COMMON NAMES : heather Scotch heather TAXONOMY : The currently accepted scientific name of heather is Calluna vulgaris (L.) Hull. (Ericaceae) [7,11,40]. There are no recognized subspecies, varieties, or forms. LIFE FORM : Shrub FEDERAL LEGAL STATUS : No special status OTHER STATUS : NO-ENTRY


SPECIES: Calluna vulgaris
GENERAL DISTRIBUTION : Heather is naturalized in North America from Newfoundland west to Michigan and south through Nova Scotia and the New England states to the mountains of West Virginia.  It is widespread throughout Europe [7,40,41]. Most of the information contained in this write-up is taken from research conducted in western Europe. ECOSYSTEMS :    FRES10  White - red - jack pine    FRES11  Spruce - fir    FRES15  Oak - hickory    FRES18  Maple - beech - birch    FRES19  Aspen - birch STATES :      CT  ME  MD  MA  MI  NH  NJ  NY  PA  RI      VT  WV  NB  NF  NS  ON  PQ BLM PHYSIOGRAPHIC REGIONS : NO-ENTRY KUCHLER PLANT ASSOCIATIONS : NO-ENTRY SAF COVER TYPES : NO-ENTRY SRM (RANGELAND) COVER TYPES : NO-ENTRY HABITAT TYPES AND PLANT COMMUNITIES : Some common plant associates of heather in Europe include Scotch pine (Pinus sylvestris), Norway spruce (Picea abies), birch (Betula spp.), heath (Erica spp.), dwarf bilberry (Vaccinium myrtillus), mountain cranberry (Vaccinium vitis-idaea), bearberry (Arctostaphylos uva-ursi), crowberry (Empetrum nigrum), willow (Salix spp.), red raspberry (Rubus idaeus), sheathed cottonsedge (Eriophorum vaginatum), bracken fern (Pteridium aquilinum), sedges (Carex spp.), hairgrass (Deschampsia flexuosa), moor-grass (Molinia spp.), reindeer lichens (Cladonia spp.), Sphagnum spp., fire moss (Ceratodon purpureus), Polytrichum spp., mountain fern moss (Hylocomium splendens), and feathermoss (Pleurozium schreberi) [1,15,43,45].


SPECIES: Calluna vulgaris
IMPORTANCE TO LIVESTOCK AND WILDLIFE : Heather leaves and shoots are the most important yearlong food of rock ptarmigan and grouse in Scotland and Denmark [39].  Heather may comprise 80 to 100 percent of the diet of grouse, and also constitutes a large portion of the diet of domestic sheep [10].  Red deer and mountain hare also browse heather [35]. PALATABILITY : NO-ENTRY NUTRITIONAL VALUE : New shoot tips of heather are higher in nitrogen, phosphorous, and copper than older stems; they decline in nutritional value after the first year [24,35]. COVER VALUE : Heather is the primary cover of the European red grouse.  Grouse use tall, old heather for cover; young, accessible shoots for food; and dense patches for breeding [35].  Heather probably also provides good cover for other upland game birds, small nongame birds, and small mammals. VALUE FOR REHABILITATION OF DISTURBED SITES : NO-ENTRY OTHER USES AND VALUES : NO-ENTRY OTHER MANAGEMENT CONSIDERATIONS : Heather has lower shoot production, decreased dry shoot weight, and reduced flowering in shaded conditions [15,20]. The quantity of lignin, condensed tannin, and phenolic compounds produced is considerably reduced under shaded conditions, making it more desirable to herbivores [20]. In simulated grazing experiments, light to medium grazing increased the number of shoot apices of heather, but heavy grazing eventually caused a decline in cover.  Summer grazing may be more detrimental than winter grazing, and older plants may be more vulnerable to grazing than younger ones [15]. Heather releases allelopathic substances that may inhibit invasion and growth of some trees in heather-dominated heaths and moors [14,48,49].


SPECIES: Calluna vulgaris
GENERAL BOTANICAL CHARACTERISTICS : Heather is an evergreen ascending shrub, usually reaching 3.3 feet (1 m) in height [7,11,41].  Growth form varies from low and sparse to dense and bushy [22].  The opposite leaves are 0.08 to 0.16 inches (0.2-0.4 cm) long, and flowers are in axillary or terminal racemes [7,11,41]. The root system is lateral and mostly buried within the top 4 inches (10 cm) of soil [13,34].  On poorly drained sites, roots may extend to 8 inches (20 cm) below ground [34].  Young plants have a taproot that is later obscured by increased growth and branching of lateral roots.  A surface mat is formed by adventitious roots and fine branches of the main root system [13]. RAUNKIAER LIFE FORM :    Phanerophyte    Chamaephyte REGENERATION PROCESSES : Heather reproduces from both seed and vegetative growth from stem bases [6,10,44]. Heather seeds are small and are dispersed by wind or animals [6,25,45]. Seeds rarely germinate without exposure to light [6,25].  They show poor germination on moss or lichen mats, possibly due to light deprivation from the moss or lichen cover.  However, a moss carpet has a positive effect on seedling performance.  Seedlings established on moss grow faster and reproduce earlier than seedlings growing on bare ground. Heather seed germination is better on mineral than organic soil and on consolidated than loose substrates.  Seeds do not germinate under waterlogged conditions [6].  Germination increases when seeds are heat-treated at temperatures of 104 to 176 degrees Fahrenheit (40-80 deg C) for 1 minute.  Exposure to temperatures above 248 degrees Fahrenheit (120 deg C) for more than 30 seconds decreases germination rates, and temperatures exceeding 392 degrees Fahrenheit (200 deg C) kill heather seeds [21].  Heather establishes large soil seedbanks [8].  Seeds are usually evenly distributed in the top 2 inches (5 cm) of soil [27]. They may remain viable for over 100 years [25].   Sprouting from the stem bases most often occurs in stands between 6 and 10 years of age and decreases in stands over 15 years old [8].  Old degenerate stands of heather may reproduce by layering [26]. On dry heaths or moors, heather generally has a life span of about 30 to 40 years and communities are usually even-aged.  In these habitats, the life cycle occurs in four distinct phases.  In the pioneer stage (0-6 years), heather establishes and grows vertically from the apex.  During the building stage (6-14 years), the plant grows laterally and forms a dense, intertwining canopy with little light penetration.  In the mature stage (14-25 years), lateral growth slows and the plant thins out in the center.  In the degenerate stage (25 or more years), central branches collapse and die, leaving a gap in the middle of the plant.  The pioneer stage is characterized by low overall biomass and high productivity; the building stage by high biomass and high productivity; and the mature and degenerate stages by high biomass and declining productivity [10]. In wet bog communities, heather does not undergo a phasic life cycle. An uneven-age structure of aboveground stems develops due to the constant burial of stems by sphagnum mosses (Sphagnum spp.) [16]. Sphagnum grows over the decumbent heather stems, leaving only young shoots above ground.  The older parts of the stem are increasingly filled with heartwood and eventually become nonfunctional.  The uneven-aged "stem population" is constantly rejuvenated so that the mean age of aboveground shoots is about 12 years and the maximum age rarely exceeds 22 years [17].  A degenerate stage does not occur [16]. SITE CHARACTERISTICS : Heather is found on nutrient-poor, acidic soils in open areas [20].  It occurs in dry fields [41], wet bogs [16,24,43], dry heathlands or moors [10,18,35], clearings in pine (Pinus spp.)-birch forests [10,43], oak (Quercus spp.) woodlands [10], and above treeline [10,12]. SUCCESSIONAL STATUS : Facultative Seral Species Heather is a slow-growing, early successional shrub [20].  It is present after logging in Scotch pine and Norway spruce stands in Sweden [2] and Finland [37].  Heather is highly intolerant of shade [15,20]. In the absence of fire, heather-dominated heaths or moors are replaced by birch and Scotch pine woodland [15,20], and in some areas by bracken fern [32].  In wet bogs, heather maintains a "steady state" without disturbance [16,17]. SEASONAL DEVELOPMENT : In North America heather flowers from July to November [7].


SPECIES: Calluna vulgaris
FIRE ECOLOGY OR ADAPTATIONS : Heather is a fire-adapted species; dense stands of heather on dry heaths require repeated fire for maintenance [5].  Removal of the forest canopy by fire increases heather abundance [23].  Following top-kill, heather sprouts from surviving stem bases and reproduces from seedbanks [10,25,44].  Sprouts and newly established seedlings flower and produce seed rapidly, possibly within the first postfire year.  This greatly increases the abundance of heather on recently burned sites [27]. POSTFIRE REGENERATION STRATEGY :    Small shrub, adventitious-bud root crown    Ground residual colonizer (on-site, initial community)    Secondary colonizer - off-site seed    Secondary colonizer - off-site seed


SPECIES: Calluna vulgaris
IMMEDIATE FIRE EFFECT ON PLANT : Exposure to temperatures greater than 932 degrees Fahrenheit (500 deg C) for more than 1 minute is lethal to heather whatever its age [8]. Severe fires may kill seeds [30].  Light to moderately severe fires may top-kill heather but usually do not damage stem bases or destroy seeds [25]. DISCUSSION AND QUALIFICATION OF FIRE EFFECT : NO-ENTRY PLANT RESPONSE TO FIRE : The response of heather to fire is highly variable and is dependent on (1) the habitat that is burned (wet bog or dry heath), (2) the phase the heather is in (pioneer, building, mature, degenerate), and (3) the temperature and duration of the fire.  The severity of grazing on young heather shoots after fire may also affect their response [36]. Most fires that occur in pioneer or building phase stands in dry heaths are light to moderately severe.  Regeneration after these fires is by sprouting from stem bases protected from the heat by litter and organic soil horizons, and from germination of seeds stored in seedbanks [25].   Severe fires which occur due to accumulation of fuel in old or very dry stands may kill stem bases.  In such cases, regeneration is from seeds alone, and is much slower than vegetative growth [10,25,28].  If seeds are killed by severe fire, establishment depends on seed dispersal from adjacent unburned areas [30].  Severely burned areas may remain bare for 70 years or more [30], or a moss or lichen mat may form which will inhibit germination of heather seeds [3,30].   DISCUSSION AND QUALIFICATION OF PLANT RESPONSE : NO-ENTRY FIRE MANAGEMENT CONSIDERATIONS : Most heaths dominated by heather are a product of interference by humans and were historically preceded by forest [30].  In western Europe, burning at regular intervals has been the principle land management practice for heaths for over 200 years and has resulted in the development of pure heather stands over vast tracts of land [17,29,31]. Heaths have been maintained for sheep and red grouse, both of which are economically important.  When managing red grouse habitat, heather is burned to provide a mosaic of stands with diverse ages, heights, and densities [31,35].  Heaths are not burned after March due to breeding and nesting [47]. In dry heaths of western Europe, fire is used to prevent tree invasion [36], maintain a balance between young and old heather shoots, and maintain heather in the building phase at the expense of other species [17].  Dominance of heather on these heaths is important because it is often the most productive and nutritious species found on dry, infertile heath soils [10].  Heather production greatly exceeds heather consumption by herbivores, resulting in a large accumulation of wood and litter.  Decomposition is slow in the cool, wet climate and acid soils of dry heaths, so a deep layer of plant litter and humus forms.  Fire removes the dead wood and litter.  If burning takes place when the vegetation is too dry or in old stands with large accumulations of dead woody material, stem bases may be killed.  Temperatures above 1,112 degrees Fahrenheit (600 deg C) increase the loss of nutrients, especially nitrogen and phosphorous, which are often already deficient in the nutrient-poor soils that heather grows in [17]. A fire interval of approximately 15 years has been suggested for the management of heather in heathlands at low to middle altitudes.  This interval maintains heather in its competitive building phase, allowing it to outcompete other species [10,35].  If intervals are longer than 15 years, the heather may be too old to sprout from stem bases or fires may be too severe.  This may lead to an extended period where the competitive vigor of heather is low, allowing the invasion of bracken fern or other undesirable species [10].  Since height is an indicator of stand phase, it can also be used as a factor in determining appropriate fire intervals.  It has been suggested that heather be burned before it reaches 12 inches (30 cm) [19]; heather more than 16 inches (40 cm) tall often burns very severely and is thus seldom targeted for prescribed fire [30].  A well-managed fire removes most of the aerial vegetation while still permitting vigorous vegetative regeneration [10,30]. Temperatures of about 752 degrees Fahrenheit (400 deg C) in the canopy and less than 392 degrees Fahrenheit (200 deg C) at the soil surface are optimal [10].  Moderate heat may stimulate germination of seeds [31].   Fire management of heather in wet bogs produces inconsistent results [10,16].  Frequent burning of wet bogs in Ireland has in some cases led to the replacement of heather by deciduous species.  This in turn has resulted in an increased amount of litter produced yearly and a lower stocking capacity for sheep in winter.  To maintain heather, areas can be burned in long rotations [24].  Longer intervals between fires (about 20 years) are also suggested for the management of wet bogs in Great Britain.  Frequent burning of heather there temporarily increases the availability of young shoots, but the resulting community is dominated by sheathed cottonsedge or moor-grass rather than heather.  Burning may not be required at all since heather remains in a "steady state" in wet bog habitats [16].


SPECIES: Calluna vulgaris
FIRE CASE STUDY CITATION : Matthews, Robin F., compiler. 1993. Heather response after moderate to severe fires on Scottish heathland. In: Calluna vulgaris. In: Fire Effects Information System, [Online]. U.S. Department of Agriculture, Forest Service, Rocky Mountain Research Station, Fire Sciences Laboratory (Producer). Available: []. REFERENCES : Hobbs, R. J.; Gimingham, C. H. 1984. Studies on fire in Scottish heathland communities. I. Fire characteristics. Journal of Ecology. 72: 223-240. [18]. Hobbs, R. J.; Gimingham, C. H. 1984. Studies on fire in Scottish heathland communities. II. Post-fire vegetation development. Journal of Ecology. 72: 585-610. [19]. SEASON/SEVERITY CLASSIFICATION : Spring/moderately-severe to severe fires STUDY LOCATION : The study sites were located on the Hill Farming Research Organization's farm at Glensaugh, Kincardineshire, Scotland. PREFIRE VEGETATIVE COMMUNITY : Prior to burning, the vegetation consisted of stands of species-poor heath classified as Callunetum and Type A Callunetum by various authors. Four stands were sampled and described in terms of growth phase of the heather (there were no degenerate stands at the site): Stand 1--pioneer (average age 5 years old, high productivity, low biomass) Stand 2--building (average age 12 years old, high productivity) Stand 3--mature (average age 14 years old, high biomass, production declining) Stand 4--mature (average age 14 years old, high biomass, production declining) Preburn frequencies (percent) of heather, hairgrass, dwarf bilberry, deer fern (Blechnum spicant), rush (Juncus squarrosus), potentilla (Potentilla erecta), and some mosses at the site were:                      Stand 1        Stand 2        Stand 3 ________________________________________________________________ heather                100            100            100 hairgrass               50.0           34.4           25.8 dwarf bilberry          94.5           63.3           57.0 deer fern                --             1.6            -- rush                     --             2.3            -- potentilla               1.6            4.7            -- Dicranum scoparium       8.6            7.0            -- Hypnum jutlandicum      20.3           35.1           32.0 Polytrichum longisetum   0.8            4.7            0.8 Preburn vegetation was not reported for Stand 4. This fire study was also conducted at another site classified as a species-rich heath of the Arctostaphyleto-Callunetum type.  Heather was codominant at that site and some of the stands were in the degenerate phase.  TARGET SPECIES PHENOLOGICAL STATE : SITE DESCRIPTION : Site characteristics for the stands follow:                      Stand 1      Stand 2      Stand 3      Stand 4 _______________________________________________________________________ Slope (deg)            10           10            7           10 Aspect                  NW           NW           NW           SW Altitude (m)           400          400          400          420 The substrate consisted of podzolized soils on quartz schist till.  Mean temperatures in the area are 30 degrees Fahrenheit (-0.8 deg C) in January and 56 degrees Fahrenheit (13.4 deg C) in July.  Annual rainfall ranges from 35 to 48 inches (870-1,190 mm). FIRE DESCRIPTION : The four stands at the site varied considerably in size but all were at least 33 by 66 feet (10 X 20 m), and all were burned on April 26, 1978. The stands were situated close to one another and some were burned by the same fire.  Prefire conditions were as follows (soil and vegetation moistures expressed as percent dry weight):                                   Stand 1    Stand 2    Stand 3    Stand 4 ___________________________________________________________________________ Soil moisture                      258         259        305        275 Vegetation moisture                101         144        129        109 Mean windspeed (m/sec)               6           6          8        8.5 Fuel consumed (g/sq m)             868        1116       2048       1688 Rate of spread (m/min)            0.25        1.33       0.33        1.0 Duration (min)                       5           4          5          5 Width of front (m)                   5          12         12         25 Maximum temperature (deg C)   Canopy                           340         620        440        660   Soil surface                     180         590        560        840 Time above 400 deg C (sec)           0          30          5         30 Time above 600 deg C (sec)           0           3          0         24 Intensity (kW/m)                    56         593        227        690 Available heat energy (MJ/sq m)   13.4        26.8       41.4       41.4 FIRE EFFECTS ON TARGET SPECIES : Temperatures and intensities increased with stand age until the mature phase.  These values declined in degenerate stands at the species-rich Arcostaphyleto-Callunetum heath site. The open, discontinuous stands (pioneer and degenerate phases) burned more slowly than the more homogenous stands (building and mature phases).  The collapse of the canopy in degenerate stands altered the fuel configuration so that fire temperatures remained relatively low. Postfire vegetative growth of heather was very rapid in the pioneer phase and led to recovery of dominance by heather.  It reached a frequency of almost 100 percent by the end of the first growing season. Less postfire vegetative growth occurred in the building phase, which resulted in a mixed heather-dwarf bilberry community at postfire year 3. Virtually no vegetative growth occurred after fire in the mature-phase stands. Heather seedlings were found in all stands from the second growing season onwards but remained infrequent except in the building stand.  In the mature stands, regeneration was almost entirely from seed.  Numerous seedlings established and subsequently died in stand four (mature phase), but their numbers increased during the third postfire growing season.  Early seedling mortality allowed dwarf bilberry and hairgrass to spread rapidly, and created a dwarf bilberry-dominated community by postfire year 3. The densities (number/sq m) of aboveground shoots and seedlings of heather in the year of the fire and in 2 successive years follow:                          Stand 1    Stand 2    Stand 3    Stand 4 ___________________________________________________________________ Vegetative shoots   1978                     157.0      60.5        3.0        1.7   1979                     106.2      51.0        2.0        2.0   1980                      70.7      43.0        2.0        2.0 Seedlings   1978                        0         0          0          0   1979                       2.5       4.2       52.0       11.5   1980                       0.7      15.7        4.5       17.0 FIRE MANAGEMENT IMPLICATIONS : Vegetation height may be a useful integrating factor for determining the state of a stand and its fuel availability.  It has been suggested that heather be burned before it reaches 12 inches (30 cm). Burning old stands of heather may lead to a rapid spread of rhizomatous species (such as dwarf bilberry) when these species were present before the fire, even in small quantities.  In old heather stands where rhizomatous species are not present, colonization by heather seedlings may take a very long time and bare ground may remain for many years.  In both cases, the lack of rapid heather regeneration is of concern since it is often the major forage species present on these species-poor heaths.  In addition, soil erosion continues until vegetative cover is established, and the risk of erosion is much greater when heather growth is delayed.  Fire, therefore, may be an unsuitable form of management in old stands of heather.


SPECIES: Calluna vulgaris
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