Insects can limit seed productivity at the treeline

2015 ◽  
Vol 45 (3) ◽  
pp. 286-296 ◽  
Author(s):  
Ryan G. Jameson ◽  
Andrew J. Trant ◽  
Luise Hermanutz
Keyword(s):  
Seed Germination ◽  
Seed Production ◽  
Seed Predation ◽  
Tree Species ◽  
Picea Glauca ◽  
Black Spruce ◽  
Abies Balsamea ◽  
Insect Larvae ◽  
Seed Productivity ◽  
Change Models

Numerous factors contribute to the variability in treeline change; however, the potential role of insect predation in limiting seed productivity is not well documented. Conditions for seed germination, establishment, and survival are not limiting at the Mealy Mountains treeline (Labrador, Canada), but seedlings are rarely encountered, suggesting a seed-related bottleneck to recruitment. Mature cones were collected in 2008 from four tree species (black spruce (Picea mariana (Mill.) Britton, Sterns & Poggenb.), balsam fir (Abies balsamea (L.) Mill.), eastern larch (Larix laricina (Du Roi) K. Koch), and white spruce (Picea glauca (Moench) Voss)) across three treeline zones (forest, transition, and krummholz) to assess potential seed limitation. During that year, an unexpectedly high diversity of insect larvae caused extensive reproductive loss and damaged the cones of ∼85% of trees sampled, confirming that treeline change models should include seed predation. Seed germination was low and variable in all treeline zones, although significantly higher in black spruce and eastern larch. Most reproductive quality measures decreased significantly with elevation, although no differences among zones or tree species in the percentages of seeds damaged by insects were found (mean ± standard deviation: 31% ± 23%). Based on tree density and seed production, black spruce is predicted to lead the treeline expansion in the Mealy Mountains. Although climate warming may create conditions conducive for increased seed production, predispersal seed predation may limit future treeline expansion.

Short-term effects of cut-to-length versus full-tree harvesting on conifer regeneration in jack pine, mixedwood, and black spruce forests in Manitoba

2004 ◽  
Vol 34 (9) ◽  
pp. 1938-1945 ◽  
Author(s):  
Isobel Waters ◽  
Steven W Kembel ◽  
Jean-François Gingras ◽  
Jennifer M Shay
Keyword(s):  
Picea Mariana ◽  
Picea Glauca ◽  
Pinus Banksiana ◽  
Black Spruce ◽  
Abies Balsamea ◽  
Jack Pine ◽  
Tree Regeneration ◽  
Understorey Vegetation ◽  
Advance Regeneration ◽  
The Impact

This study compares the effects of full-tree versus cut-to-length forest harvesting methods on tree regeneration in jack pine (Pinus banksiana Lamb.), mixedwood (Picea glauca (Moench) Voss – Populus tremuloides Michx. – Abies balsamea (L.) Mill.), and black spruce (Picea mariana (Mill.) BSP) sites in southeastern Manitoba, Canada. We surveyed tree regeneration densities, disturbance characteristics, and understorey vegetation in replicated control and harvested plots in each site type preharvest (1993) and 1 and 3 years postharvest (1994, 1996). In jack pine sites, the full-tree harvest method promoted regeneration of Pinus banksiana through increased disturbance of soil and the moss layer, and decreased slash deposition relative to the cut-to-length method. Conversely, in mixedwood sites the cut-to-length method resulted in less damage to advance regeneration and proved better at promoting postharvest regeneration of Abies balsamea and Picea glauca relative to the full-tree method. In black spruce sites, there were few differences in the impact of the two harvesting methods on regeneration of Picea mariana, which increased in frequency and density after both types of harvesting.

Development of an improved model estimating the nutrient content of the bole for four boreal tree species

1998 ◽  
Vol 28 (1) ◽  
pp. 37-43 ◽  
Author(s):  
P Rochon ◽  
D Paré ◽  
C Messier
Keyword(s):  
Populus Tremuloides ◽  
Tree Species ◽  
Picea Glauca ◽  
Nonlinear Models ◽  
Abies Balsamea ◽  
Nutrient Content ◽  
Forest Harvesting ◽  
Nutrient Concentrations ◽  
Nutrient Contents ◽  
Improved Model

An improved model for estimating nutrient contents of the commercial portion of tree boles was developed for four boreal tree species (Populus tremuloides Michx., Betula papyrifera Marsh., Picea glauca (Moench) Voss, and Abies balsamea (L.) Mill.). This model considers the spatial pattern of variation of nutrient concentrations inside the bole and its relationships with tree size. For all species-nutrient combinations, no significant pattern was found for vertical variations in nutrient concentrations, while two types of nonlinear models, using distance from the tree periphery as the independent variable, fit the pattern of horizontal (or radial) variations. These patterns of variability were used to estimate the global nutrient concentration of the bole by using mathematical integration. The values obtained with this method were generally lower, especially for large stems, than values obtained with traditional methods that do not consider the variability of nutrient concentrations inside the bole. This improved model would permit better estimates of the amounts of nutrients lost in biomass upon forest harvesting, as well as internal cycling of nutrients within the bole.

Résistance comparée de l'épinette blanche et du sapin baumier au renversement

2002 ◽  
Vol 32 (4) ◽  
pp. 642-652 ◽  
Author(s):  
S Meunier ◽  
J -C Ruel ◽  
G Laflamme ◽  
A Achim
Keyword(s):  
Tree Species ◽  
Picea Glauca ◽  
Abies Balsamea ◽  
White Spruce ◽  
Diameter Ratio ◽  
Balsam Fir ◽  
Species Vulnerability ◽  
Mesic Site ◽  
Linear Regressions ◽  
Tree Characteristics

Information on eastern Canadian tree species vulnerability to windthrow is scarce. Some statements on relative species vulnerability have been made but they rely on empirical observations, which are often difficult to generalize. In this context, a study was conducted to compare the overturning resistance of balsam fir (Abies balsamea (L.) Mill.) and white spruce (Picea glauca (Moench) Voss) on a mesic site. To establish which tree characteristics would best explain the critical turning moment, simple linear regressions were calculated using tree dendrometric data. The best regressions were obtained with stem weight. With this variable, resistance to overturning did not differ between the two species. Only regressions involving total height showed a significantly greater resistance for white spruce. This difference can be explained by a difference between the species in height–diameter relationships. For a similar height, spruce has a greater diameter, involving a higher stem weight and thus a greater resistance. Decay did not play a major role in our experiment as trees with external defects were excluded. Our results suggest that to minimize losses from windthrow, silvi cultural treatments on mesic sites should try to increase the proportion of trees of either species with the lowest height/diameter ratio.

Fire return intervals and tree species succession in the North Shore region of eastern Quebec

2008 ◽  
Vol 38 (6) ◽  
pp. 1621-1633 ◽  
Author(s):  
Mathieu Bouchard ◽  
David Pothier ◽  
Sylvie Gauthier
Keyword(s):  
Tree Species ◽  
Forest Succession ◽  
Black Spruce ◽  
Abies Balsamea ◽  
Balsam Fir ◽  
Geographic Variations ◽  
Forest Patches ◽  
The North ◽  
Species Succession ◽  
South Axis

We evaluated geographic variations in mean fire return intervals and postfire forest succession within a 66 497 km2 land area located in the eastern Quebec boreal forest. Fire return intervals were calculated using a time since last fire map for 1800–2000, and forest dynamics were studied by superimposing 3204 forest inventory plots onto the fire map. Mean fire return interval proved significantly shorter in the western part of the study area, at 270 years, compared with the eastern part, where it was probably more than 500 years. The two main tree species in the study area were balsam fir ( Abies balsamea (L.) P. Mill.) and black spruce ( Picea mariana (Mill.) BSP). Balsam fir abundance increased progressively as a function of time since fire, whereas black spruce abundance increased during the first 90 years after fire and then declined. Balsam fir was significantly more abundant in the southeastern portion of the study area, which we attribute to the combined limitations imposed by temperature along the north–south axis and by fire along the east–west axis. Large forest patches (i.e., ≥200 km2) dominated by early successional tree species, within a matrix of irregular black spruce – balsam fir mixtures, are an important feature of preindustrial forest landscapes in this region.

scholarly journals White spruce enrichment planting in boreal mixedwoods as influenced by localized site preparation: 11-year update

2020 ◽  
Vol 96 (01) ◽  
pp. 27-35
Author(s):  
Myriam Delmaire ◽  
Nelson Thiffault ◽  
Evelyne Thiffault ◽  
Julie Bouliane
Keyword(s):  
Picea Glauca ◽  
Native Species ◽  
Black Spruce ◽  
Abies Balsamea ◽  
Basal Area ◽  
White Spruce ◽  
Site Preparation ◽  
White Birch ◽  
Ecosystem Based Management ◽  
Enrichment Planting

Ecosystem-based management aims to maintain the natural proportion of native species over a given landscape. White spruce (Picea glauca (Moench) Voss) is a species sensitive to environmental conditions; it is especially demanding in terms of nutrients and its regeneration is negatively affected by clearcut harvesting. Its proportion is now significantly lower than what it was in the preindustrial forests of Québec (Canada). As a native species in boreal Québec, efforts to maintain its proportion in the landscape are undertaken for white spruce, but little is known about the best practices to maximize establishment success of seedlings planted in the balsam fir (Abies balsamea)–white birch (Betula papyrifera) bioclimatic domain. Our general objective was to identify planting practices as related to microsite treatment that favour white spruce sapling survival and size after 11 growing seasons following enrichment planting of sites harvested by mechanized careful logging in an ecosystem-based management context. We also aimed at comparing white spruce performance with that of black spruce (Picea mariana (Mill.) BSP), a native species that is less sensitive to abiotic stress. Finally, we wanted to assess stand composition at this juvenile stage, as a function of microsite treatment and planted species. Localized site preparation did not significantly affect growth or survival for white spruce compared to control conditions. Furthermore, localized site preparation did not increase the proportion of white and black spruce, as evaluated by basal area. Our results suggest that white spruce can be successfully established in enrichment planting in fir-dominated boreal forests, without site preparation.

Dendroclimatic response of a coastal alpine treeline ecotone: a multispecies perspective from LabradorThis article is a contribution to the series Tree recruitment, growth, and distribution at the circumpolar forest–tundra transition.

2011 ◽  
Vol 41 (3) ◽  
pp. 469-478 ◽  
Author(s):  
M. Trindade ◽  
T. Bell ◽  
C. P. Laroque ◽  
J. D. Jacobs ◽  
L. Hermanutz
Keyword(s):  
Picea Glauca ◽  
Radial Growth ◽  
Black Spruce ◽  
Abies Balsamea ◽  
White Spruce ◽  
Climate Variables ◽  
Climate Trends ◽  
Treeline Ecotone ◽  
Alpine Treeline ◽  
Temperature And Precipitation

Coastal alpine forests are highly vulnerable to oceanic climate trends, yet these diverse environmental interactions remain poorly understood. We used a multispecies perspective to try to better assess the radial growth response of alpine treeline species within the Northeast Atlantic region of North America to climate variables using bootstrapped correlation analysis. The four species present, black spruce (Picea mariana (Mill.) B.S.P.), white spruce (Picea glauca (Moench) Voss), balsam fir (Abies balsamea (L.) Mill.), and eastern larch (Larix laricina (Du Roi) K. Koch) were sampled in an effort to capture tree–climate sensitivity that is representative of this entire alpine treeline. The climate–growth relationships of spruce trees were comparable with those reported in other Labrador studies, but spring drought sensitivity as reported for coastal northern white spruce trees was not observed. Rather, high levels of precipitation suggest that drought did not limit the radial growth of any of the four species. The relatively small number of statistically significant correlations between monthly climate variables and fir and larch trees suggests that factors other than climate limit their radial growth. The multispecies approach better highlighted the range of species-specific relationships between alpine treeline forests and maritime climates (monthly temperature and precipitation) found at the treeline ecotone.

Host–tree oviposition preference of balsam fir sawfly, Neodiprion abietis (Hymenoptera: Diprionidae), in New Brunswick, Canada

2013 ◽  
Vol 145 (4) ◽  
pp. 430-434
Author(s):  
Rob C. Johns ◽  
J. Fidgen ◽  
Don P. Ostaff
Keyword(s):  
New Brunswick ◽  
Host Plant ◽  
Picea Glauca ◽  
Black Spruce ◽  
Oviposition Preference ◽  
Abies Balsamea ◽  
Balsam Fir ◽  
Neodiprion Abietis ◽  
Plant Foliage ◽  
Female Longevity

AbstractLaboratory experiments using field-collected females were carried out to determine the oviposition preference of the balsam fir sawfly, Neodiprion abietis (Harris) (Hymenoptera: Diprionidae) in New Brunswick, Canada. Unmated adult females given no choice among host–plant foliage laid ∼98% of available eggs on balsam fir (Abies balsamea (Linnaeus) Miller; Pinaceae), but only 8% and 10%, respectively, on white spruce (Picea glauca (Moench) Voss; Pinaceae) and black spruce (Picea mariana (Miller) Britton, Sterns, and Poggenburg). Given a choice among shoots from all three hosts in the same chamber, unmated females laid all but one egg in balsam fir. Host plant had no effect on female longevity, although there were nearly four- to eightfold more empty egg slits on balsam fir needles, owing presumably to the greater activity of females on this preferred host foliage.

Predispersal seed predation on three Vachellia species and one Senegalia species (Fabaceae: Mimosoideae) in the Rift Valley of Ethiopia and Menagesha forest, Ethiopia

2016 ◽  
Vol 36 (02) ◽  
pp. 91-96 ◽  
Author(s):  
Abraham Yirgu
Keyword(s):  
Seed Germination ◽  
Seed Predation ◽  
Tree Species ◽  
Rift Valley ◽  
Seed Predators ◽  
Leguminous Species ◽  
Unidentified Species ◽  
Senegalia Senegal ◽  
Predispersal Seed Predation ◽  
Seed Beetles

AbstractThis study on predispersal seed predation of the leguminous speciesVachellia abyssinica(Hochst. Ex. Benth.) Kyal & Boatwr.,Senegalia senegal(L.) Britton,Vachellia seyal(Del.) P.J.H. Hurter, andVachellia tortilis(Forssk.) Galasso & Banfi was conducted around Lake Langano and Menagesha Forest in Ethiopia to identify the associated seed predators and determine their impact on seed germination. Eight seed beetlesBruchidius albosparsus(Fåhraeus, 1839),B. aurivillii(Blanc, 1889),B. djemensisDecelle 1971,B. discoidalis(Fåhraeus, 1839),B. sinaitus(K. Daniel, 1907),B. silaceus(Fåhraeus, 1839),B. sp 411,B. simulans(Anton and Delobel, 2003), and one unidentified species of Cerambycidae were found associated with seeds of theseAcaciaspecies. These predators damaged less than 9% of seeds of these species, which exhibited lower germination. This study provides unrecorded lists of predispersal seed predators associated with seeds ofVachelliaandSenegaliaspecies in Ethiopia, and some associations are new. There is need to assess the distribution, abundance and effects of predispersal seed predators on otherVachellia, as well as other tree species.

Carry-over effect of host nutritional quality on performance of spruce budworm progeny

2011 ◽  
Vol 102 (3) ◽  
pp. 275-284 ◽  
Author(s):  
A. Fuentealba ◽  
É. Bauce
Keyword(s):  
Picea Glauca ◽  
Nutritional Quality ◽  
Black Spruce ◽  
Choristoneura Fumiferana ◽  
Abies Balsamea ◽  
Poor Performance ◽  
Spruce Budworm ◽  
The Other ◽  
Offspring Performance ◽  
Laboratory Rearing

AbstractThe effect of host nutritional quality on spruce budworm (Choristoneura fumiferana (Clemens)) parental and offspring performance was studied using field and laboratory rearing experiments, and foliar chemical analyses. Foliage of balsam fir (Abies balsamea (L.) Mill.), white spruce (Picea glauca (Moench) Voss) and black spruce (P. mariana (Mill.) BSP) was used to rear the parental generation in the field, whereas an artificial diet was used to rear the progeny under laboratory conditions. Important differences in the food quality were provided by the three hosts. Black spruce foliage had higher concentrations of certain monoterpene deterrents and total phenolics, together with stronger seasonal declines in nutrients such as N, P and Mg, compared with the other hosts. We hypothesise that this trend may be related to poor performance and survival of the progeny. Laboratory rearing showed that progeny of parents that fed on black spruce exhibited longer developmental times and greater mortality, and had lower pupal mass than progeny of parents fed on the other hosts. Further, artificial food-fed progeny of insects reared on black spruce reached sixth-instar later, with lower mass, and exhibited higher relative growth rate (RGR) than progeny of parents fed on the other hosts. These results suggest nutritionally-based parental effects. These results also confirmed that the quality of food consumed by the parents can influence the fitness of the next generation.

Sign in / Sign up

Export Citation Format

Share Document