Treesearch

Spray-dried cellulose nanocrystal (SDCNC) particles have attracted intense interest as reinforcements in polymer composites because of their unique physical and mechanical properties. This work aims to develop homopolymer polypropylene (HPP) composites with different loading levels of SDCNC particles (5, 10, 15, and 30 wt%) to understand their impact on composite mechanical, morphological, and thermal properties. The SDCNC-reinforced HPP composites were manufactured using a C.W. Brabender bowl internal mixer with a masterbatch concept and an injection molding process. The mechanical,...

Wildfires are increasingly frequent in the Western US and impose a number of costs including from the instantaneous release of carbon when vegetation burns. Carbon released into the atmosphere aggravates climate change while carbon stored in vegetation helps to mitigate climate change. The need for climate change mitigation is becoming more and more urgent as achieving the Paris climate agreement target of limiting global warming to 1.5 °C seems ever more challenging. A clear understanding of the role of different carbon sources is required for understanding the degree of progress toward...

Emerging infectious diseases threaten natural and managed trees worldwide – causing reduced vigour, increased mortality and, occasionally, extirpation – yet we have little understanding of how emerging diseases have accumulated over time and how accumulation has varied by host species, host nativity and in different global regions. To address this challenge, I assembled over 900 new disease reports on 284 tree species in 88 countries and quantified how emerging infectious diseases have accumulated geographically and on different hosts. I show disease accumulation is increasing rapidly...

Protein and carbohydrate content in the diet of the predator Hippodamia variegata Goeze (variegated ladybug) directly influences reproduction fitness by affecting foraging efficiency. The effect of three varied qualities of Aphis gossypii Glover (cotton aphid) prey on daily H. variegata feeding and daily egg production (DEP) were estimated using the support vector machine (SVM). The SVM can predict predator reproductive behavior as a function of the relationship between foraging and prey nutritional composition. We used the total number and weight of aphids consumed, volume of protein,...

Statistical analyses of wildfire growth are rarely undertaken, particularly in South America. In this study, we describe a simple and intuitive difference equation model of wildfire growth that uses a spread parameter to control the radial speed of the modeled fire and an extinguish parameter to control the rate at which the burning perimeter becomes inactive. Using data from the GlobFire project, we estimate these two parameters for 1003 large, multi-day fires in Peru between 2001 and 2020. For four fire-prone ecoregions within Peru, a set of 24 generalized linear models are fit for each...

Climate warming, land use change, and altered fire regimes are driving ecological transformations that can have critical effects on Earth's biota. Fire refugia - locations that are burned less frequently or severely than their surroundings - may act as sites of relative stability during this period of rapid change by being resistant to fire and supporting post-fire recovery in adjacent areas. Because of their value to forest ecosystem persistence, there is an urgent need to anticipate where refugia are most likely to be found and where they align with environmental conditions that support...

The European winter moth, Operophtera brumata L. (Lepidoptera: Geometridae), was accidentally introduced to North America on at least 4 separate occasions, where it has been hybridizing with the native Bruce spanworm, O. bruceata Hulst, at rates up to 10% per year. Both species are known to respond to the same sex pheromones and to produce viable offspring, but whether they differ in the seasonal timing of their mating flights is unknown. Therefore, we collected adult male moths weekly along 2 transects in the northeastern United States and genotyped individuals using polymorphic microsatel...