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Wildland fires have a multitude of ecological effects in forests, woodlands, and savannas across the globe. A major focus of past research has been on tree mortality from fire, as trees provide a vast range of biological services. We assembled a database of individual-tree records from prescribed fires and wildfires in the United States. The Fire and Tree Mortality (FTM) database includes records from 164,293 individual trees with records of fire injury (crown scorch, bole char, etc.), tree diameter, and either mortality or top-kill up to ten years post-fire. Data span 142 species and 62 genera, from 409 fires occurring from 1981-2016. Additional variables such as insect attack are included when available. The FTM database can be used to evaluate individual fire-caused mortality models for pre-fire planning and post-fire decision support, to develop improved models, and to explore general patterns of individual fire-induced tree death. The database can also be used to identify knowledge gaps that could be addressed in future research., Measurement(s)plant morphology trait • tree mortality • fire • tree fire injury • wildfireTechnology Type(s)digital curationFactor Type(s)year of data collection • geographic location of fire • tree fire injurySample Characteristic - OrganismtreesSample Characteristic - Environmentforest ecosystemSample Characteristic - LocationCascades Region • Blue Mountains • Far Northern Rockies • Sierra Nevada • Piedmont Province • Region of Piedmont • Atlantic and Gulf Coastal Plain Floristic Province • Northern Rocky Mountains Provincial Park Machine-accessible metadata file describing the reported data: 10.6084/m9.figshare.12369293

Bark beetles and their predators are useful systems for addressing questions concerning diet breadth and prey preference in arthropod natural enemies. These predators use bark beetle pheromones to locate their prey, and the response to different pheromones is a measure of prey preference. 2. Trapping experiments were conducted to examine geographic variation in the response to prey pheromones by two bark beetle predators, Thanasimus dubius and Temnochila virescens. The experiments used pheromones for several Dendroctonus and Ips prey species (frontalin, ipsdienol, and ipsenol) and manipulated visual cues involved in prey location (black vs. white traps). The study sites included regions where the frontalin-emitter Dendroctonus frontalis was in outbreak vs. endemic or absent. 3. There was significant geographic variation in pheromone preference for T. dubius. This predator strongly preferred a pheromone (frontalin) associated with D. frontalis at outbreak sites, while preference was more even at endemic and absent sites. No geographic variation was found in the response by T. virescens. White traps caught fewer insects than black traps for both predators, suggesting that visual cues are also important in prey location. 4. The overall pattern for T. dubius is consistent with switching or optimal foraging theory, assuming D. frontalis is a higher quality prey than Ips. The two predator species partition the prey pheromones in areas where D. frontalis is abundant, possibly to minimise competition and intraguild predation.

Pinus resinosa is an ecologically and economically important native pine of the northern Great Lakes region, USA. The survival of adult trees can be challenged by fire, physical wounding, fungal pathogens, and bark beetles, which frequently occur in combination. We conducted experiments to test for interactions among these disturbance agents. Specifically, we measured responses of the oleoresin defense system to simulated ground fires and mechanical wounding, together and alone. Then we measured the attraction of study trees to ambient populations of Ips bark beetles, and their suitability as hosts for four species of necrotizing fungal pathogens commonly associated with Ips spp. P. resinosa responded to scorching and mechanical wounding with an initial decrease in resin defenses, which returned to pre-treatment levels in 7–10 days and continued to increase until resin flow was about twice that of control trees after 55 days. Fungal inoculation also produced an approximate doubling of resin flow after 55 days. Combinations of treatments did not increase resin flow more than single treatments. There were consistent differences among sympatric species of fungi in the size of lesions that were produced from standardized inoculations of the phloem, but lesion sizes were unaffected by previous exposure of trees to fire. Landings by Ips pini and I. grandicollis were unrelated to fire damage or physical wounding, but bark beetle attacks (entry into the phloem) were concentrated within the scorched region of trees exposed to fire. Fire, fungi, and bark beetle attacks, but not mechanical wounding, induced a strong localized reaction that rendered the affected phloem tissue dark and resin soaked; this tended to contain the tissue damage and usually killed the fungi and/or beetles, but was generally associated with death of the adjacent cambium. Our results suggest the possibility of fire-driven coevolution between P. resinosa and Ips.

The bark beetleIps pini (Say) displays variation in its response to and production of enantiomeric blends of its pheromone ipsdienol. One of the principal predators ofIps pini isThanasimus dubius (F.), which uses ipsdienol as a kairomone for prey location. During 1988 and 1989, in Wisconsin and Michigan, the response of both species to a range of enantiomeric blends of ipsdienol was investigated. Blends tested had the following ratios of the (S)-(+) to (R)-(-) enantiomers: 3%∶97%, 25%∶75%, 50%∶50%, 75%∶ 25%, and 97%∶ 3%. Either 75% (+)∶25% (-) or 50% (+)∶50% (-) ipsdienol captured the mostIps pini in both years at both sites. The 25% (+)∶75% (-) blend also caught moreIps pini than the control during both years at both sites. All blends tested were attractive toThanasimus dubius in both years at both locations. Blend preferences of both species were variable and labile at both sites. Response patterns of both species in Wisconsin were different from those in Michigan each year. Furthermore, response patterns of both species to the ipsdienol blends changed from 1988 to 1989 at both locations. A genetic component to this variation would permit predator-prey coevolution, as well as the development of resistance byIps pini to management strategies based on mass-trapping with single blends.

The bark beetles Ips pini, I. perroti, and I. grandicollis are sympatric in pine forests of the north-central United States. They share the same limited phloem resource and often coexist within the same host trees. We tested whether phloem resources are partitioned in time and space by measuring spatial and seasonal colonization of logs. Differences among species in flight phenology, development time, voltinism, and spatial colonization patterns within logs reduce, but do not eliminate, species overlap. The bark beetle species share predation by Thanasimus dubius (Cleridae) and Platysoma cylindrica (Histeridae), which exploit pheromone signals for prey location. We employed pheromone traps to test for chemical communication among bark beetle species. Heterospecific signals tend to be deterrents when they are added to conspecific signals but attractants when they are alone, indicating that the communication system can both reduce and increase species overlap in resource use depending upon relative abundance of the species. Deterrence by heterospecific signals is probably a result of selection for minimizing interspecific competition. However, individuals may sometimes benefit from joining aggregations of other species because of (1) predator swamping, (2) improved success in attacking live trees, and (3) location of suitable, recently dead, trees. These benefits should be greatest for males (which locate and colonize host trees before signalling females) and indeed males tended to be more attracted than females by heterospecific signals. Shared resources, shared predators, and heterospecific pheromone communication all contribute to species interactions in this guild of bark beetles, but predicting whether the removal of one species will tend to increase or decrease the abundance of remaining species remains difficult. Species interactions are likely conditional and coexistence is probably promoted by benefits to rare species of multispecies associations.