•Five-needle pines need to adapt to white pine blister rust and climate change.•Mortality during natural selection puts populations at risk for extirpation.•Population recovery depends on ...regeneration, and resistance and tolerance traits.•Climate change increases the risk of mortality by other pests, pathogens, and fire.•Targeted management can facilitate adaptation and increase resilience.
Tree mortality rates have been increasing globally with mountainous regions experiencing higher temperatures and impacts from the expansion and intensification of pests and invasion by non-native agents. Western North American high-elevation forests exemplify these trends, and they often include one or more species of five-needle white pines (High-5 hereafter). These species share many characteristics critical to defining the structure and function of many subalpine forests. The main threats to High-5 populations include the non-native pathogen Cronartium ribicola, which causes the disease white pine blister rust, climate-driven drought stress, episodic and high mortality from mountain pine beetle (Dendroctonus ponderosae), and wildfires of increasing frequency, size, and intensity. The six High-5 species occurring in western North America (whitebark pine, Pinus albicaulis; limber pine, P. flexilis; southwestern white pine, P. strobiformis; Rocky Mountain bristlecone pine, P. aristata; Great Basin bristlecone pine, P. longaeva; and foxtail pine, P. balfouriana) differ in their health status and threat level. The convergence of threats impacting the rapidly declining species could portend future declines in the species and populations currently less impacted by recent disturbances. Differences in the innate adaptive capacities of the species affect their population trajectories under these novel combinations of stressors. We evaluate the status and outlook for each species and address the following questions: (1) Is the environment changing too fast and the intensity of stressors too great for the species to adapt and recover? (2) Do the species have the heritable traits necessary to sustain fitness under C. ribicola and climatic stresses? (3) Are other mortality factors increasing to the degree that they reduce the populations further and delay or preclude adaptation and population recovery? (4) Can the species escape the stressors through migration? Insights related to these questions provide guidance for forest management to facilitate adaptation and increase the resilience of these species into the future.
Full text
Available for:
GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
Just as farmers plant the best-available varieties of crops that have been developed through many generations of breeding, forest landowners should plant the best-available genetically improved ...varieties of pines for reforestation of their timberlands. This 8-page fact sheet written by Timothy L. White, Mary L. Duryea, and Gregory L. Powell and published by the UF/IFAS School of Forest Resources and Conservation explains how planting genetically improved varieties of pines can increase the productivity, health, and value of reforested Florida timberlands. edis.ifas.ufl.edu/fr007
Mountain pine beetle (MPB, Dendroctonus ponderosae) is a significant mortality agent of Pinus, and climate-driven range expansion is occurring. Pinus defenses in recently invaded areas, including ...high elevations, are predicted to be lower than in areas with longer term MPB presence. MPB was recently observed in high-elevation forests of the Great Basin (GB) region, North America. Defense and susceptibility in two long-lived species, GB bristlecone pine (Pinus longaeva) and foxtail pine (P. balfouriana), are unclear, although they are sympatric with a common MPB host, limber pine (P. flexilis).
We surveyed stands with sympatric GB bristlecone–limber pine and foxtail–limber pine to determine relative MPB attack susceptibility and constitutive defenses.
MPB-caused mortality was extensive in limber, low in foxtail and absent in GB bristlecone pine. Defense traits, including constitutive monoterpenes, resin ducts and wood density, were higher in GB bristlecone and foxtail than in limber pine.
GB bristlecone and foxtail pines have relatively high levels of constitutive defenses which make them less vulnerable to climate-driven MPB range expansion relative to other highelevation pines. Long-term selective herbivore pressure and exaptation of traits for tree longevity are potential explanations, highlighting the complexity of predicting plant–insect interactions under climate change.
Full text
Available for:
BFBNIB, FZAB, GIS, IJS, KILJ, NLZOH, NMLJ, NUK, OILJ, PNG, SAZU, SBCE, SBMB, UL, UM, UPUK
Key message
Exogenous MJ does not alter the resin duct structure of pines in the cortex, but increases the number, density and mean size of resin ducts in the secondary xylem, particularly in
Pinus ...sylvestris
and
P. radiata
.
Methyl jasmonate (MJ) is an organic compound capable of modulating defence responses in plants. Exogenous application of MJ has been shown to modify the structure of the resin canal system in conifers by inducing the formation of dense concentric bands of traumatic resin ducts in the xylem. Because inducibility of resin ducts has been little explored across pine species, 3-year-old
Pinus pinaster
,
P. pinea
,
P. sylvestris
and
P. radiata
trees were sprayed with 0, 25 and 50 mM solutions of MJ, and plant growth, external symptoms and histology were assessed 60 days after treatment. Exogenous application of MJ diminished primary or secondary growth in all species (61 and 25%, respectively) and caused needle damage in
P. sylvestris
. Exogenous MJ did not alter the resin duct structure of
Pinus
spp. in the cortex. In the secondary xylem, however, the effect of MJ differed considerably between species: ducts, duct density and area covered by ducts increased in
P. sylvestris
and
P. radiata
, but not in
P. pinaster
and
P. pinea
. In MJ 50 mM-treated trees, resin duct abundance peaked at the first half of the ring in
P. sylvestris
and at one-third distance from the previous ring in
P. radiata
. In MJ treated
P. radiata
trees, large traumatic axial resin ducts, 120–160 µm in diameter, were aligned in the secondary xylem. The study helps to elucidate macroevolutionary aspects of inducibility of resin-based defences in the genus
Pinus
, where varying responses to MJ could reveal different defence strategies among species.
Full text
Available for:
EMUNI, FIS, FZAB, GEOZS, GIS, IJS, IMTLJ, KILJ, KISLJ, MFDPS, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, SBMB, SBNM, UKNU, UL, UM, UPUK, VKSCE, ZAGLJ
•Predictive models of southern and western pine consumption are presented.•Fuel consumption modeling is an important step in emissions prediction and prescribed burn planning.•Models fall within the ...range of observed biomass and consumption in independent datasets.•Southern pine models of herbs, shrub and fine wood have close model fit with narrow prediction intervals.•Models of coarse wood, litter and duff have greater uncertainty, particularly at high pre-burn biomass.
Reliable estimates of pre-burn biomass and fuel consumption are important to estimate wildland fire emissions and assist in prescribed burn planning. We present empirical models for predicting fuel consumption in natural fuels from 60 prescribed fires in ponderosa pine-dominated forests in the western US and 60 prescribed fires in long-needle pine forests in the southeastern US. There was high variability across sites, but total surface fuel biomass was generally much lower on southern sites (23.0±11.6Mgha−1) than western sites (61.5±35.8Mgha−1). Differences in surface fuel composition, pre-burn loading and fuel consumption between the southern and western pine consumption datasets justify the development of regional models for predicting fuel consumption. Southern pine models of herb, shrub and 1-h consumption have close model fit with narrow prediction intervals across the range of sampled values. Relationships between 10-h and 100-h pre-burn loading and consumption produced models with reasonable fit but with no significant correlation with fuel moisture. Model fit of litter and duff consumption models was relatively poor compared to the other southern fuel categories. Western models were developed for 1-h, 10-h and 100-h fine wood, sound coarse wood, rotten coarse wood, litter and duff. All western models had high coefficients of variability, and model residuals indicate higher uncertainty with increasing pre-burn biomass. Although empirical models are widely used, they have limitations in that they are constrained by burning conditions and ranges of predictor variables.
Full text
Available for:
GEOZS, IJS, IMTLJ, KILJ, KISLJ, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UL, UM, UPCLJ, UPUK, ZRSKP
Pinus species are important in traditional medicine throughout their ranges, and pine essential oils are of interest in aromatherapy and as topical treatments. In this work, the leaf (needle) ...essential oils of Pinus ponderosa var. ponderosa and Pinus contorta subsp. contorta from Oregon and Pinus flexilis growing in Idaho, have been obtained by hydrodistillation and analyzed by gas chromatographic techniques. The leaf essential oil of P. ponderosa was dominated by β-pinene (21.5–55.3%), methyl chavicol (8.5–41.5%), α-pinene (3.6–9.6%), δ-3-carene (3.6–6.2%), and α-terpineol (1.4–5.3%). The major components of P. contorta essential oil were β-phellandrene (23.8%), terpinen-4-ol (11.0%). The essential oil of P. flexilis was dominated by α-pinene (37.1%), β-pinene (21.9%), bornyl acetate (12.8%), and camphene (8.5%). Chiral gas chromatography revealed the enantiomeric ratios of α-pinene and limonene to be variable, but (−)-β-pinene predominated in Pinus essential oils.
Full text
Available for:
IZUM, KILJ, NUK, PILJ, PNG, SAZU, UL, UM, UPUK
The pine‐tree lappet moth, Dendrolimus pini (L.) (Lepidoptera: Lasiocampidae), is a pest whose natural range mostly follows that of its host, Scots pine, Pinus sylvestris L. (Pinaceae). Under natural ...conditions, we observed differences in larval body size, pointing to different rates of their growth and development. This study aimed to check whether differences in egg mass can differentiate the growth and development rate of D. pini larvae. We assumed that decrease in egg mass on subsequent days of oviposition can have a large impact. Our results indicate that there is an unusually strong fecundity advantage of large female mass in D. pini, but with each day of laying, the mean mass of the eggs decreases. However, offspring phenotype and development in D. pini is not clearly correlated with egg mass. We also confirmed a strong decrease in the number and mass of eggs on subsequent days of oviposition. However, egg mass decline did not correspond with the performance of the offspring in a laboratory rearing because the specimens formed from ‘medium‐mass’ eggs were characterized by the highest fitness. Although we noted a significant impact of the day of oviposition on some offspring's fitness parameters (e.g., development stage duration, pupal mass, adult mass), the variation was not large. The offspring hatched from eggs on the 3rd day of oviposition were characterized by increased values of some parameters (e.g., higher mass, heavier cocoons, faster development). Variation in the development of the larvae could be a strategy to help offspring survive under short‐term unfavorable conditions, and also reduces intra‐species competition which is generally beneficial.
In nature, we observed differences in Dendrolimus pini (Lepidoptera: Lasiocampidae) larval body size, pointing to different rates of growth and development. We studied whether differences in egg mass can differentiate these parameters. There appears a strong fecundity advantage of large female mass in D. pini, but with each day of laying, the mean egg mass decreased. Oviposition day had a significant impact on some fitness parameters. The specimens formed from ‘medium‐mass’ eggs were characterized by the highest fitness.
Full text
Available for:
BFBNIB, FZAB, GIS, IJS, KILJ, NLZOH, NUK, OILJ, SBCE, SBMB, UL, UM, UPUK
PDF
