The Jones Center at Ichauway

The extension of NASA’s Ice, Cloud, and land Elevation Satellite-2 (ICESat-2) mission beyond the cryosphere to include the study of vegetation and the land surface has significantly advanced global Earth observation. This review synthesizes findings from 293 peer-reviewed articles and provides a comprehensive assessment of the mission’s contributions to terrestrial ecosystem science. We begin by outlining the mission’s objectives, instrumentation, and core data products—particularly ATL03 (geolocated photons) and ATL08 (terrain and canopy heights)—which have supported a wide array of applications in forestry, terrain analysis, and environmental monitoring. Our analysis shows that most studies focus on temperate and tropical broadleaf forests, with a strong emphasis on estimating canopy height, terrain elevation, and forest structure. Terrain metrics derived from ICESat-2 products typically achieve high accuracy, while vegetation variables, such as canopy height, cover, leaf area index (LAI), and aboveground biomass, demonstrate moderate to strong accuracies across biomes. While parametric models remain the most used approach, machine learning methods are expanding, and more than one third of the reviewed literature incorporates synergistic analyses with other satellite missions. Despite its versatility, ICESat-2 remains underutilized in several key domains—including nonforest vegetation, fire ecology, wildlife habitat assessment, urban monitoring, and disturbance detection—mainly due to the scarcity of standardized algorithms and validated reference datasets. However, the growing availability of open source processing tools presents a significant opportunity for expanding the user base and fostering innovation in these emerging areas. Future advancements, such as the forthcoming ATL18 gridded canopy height and terrain products, alongside synergies with missions like the European Space Agency (ESA)’s BIOMASS and the NASA–Indian Space Research Organisation (ISRO) Synthetic Aperture Radar (NISAR), promise to enhance multisensor integration and ecosystem monitoring. Overall, ICESat-2 continues to evolve as a powerful resource for characterizing vegetation structure, ecosystem dynamics, and land surface processes on a global scale.

High-performance liquid chromatography (HPLC) is an invaluable technique that has been used for many decades for the separation of various molecules. The reproducible collection of eluates from these systems has been significantly improved via its automation by fraction collection systems. Current commercially available fraction collectors are not easily customizable, incompatible with other platforms, and come with a large cost barrier making them inaccessible to many researchers. Here we present the efficient construction of a low-cost customizable fraction collector that can easily be paired to any HPLC system. Notably, it supports significantly larger volumes for collection than commercial alternatives. Using a hobbyist-grade three-dimensional (3D) printer (Creality Ender 3 Pro) and aluminum extrusions, the fraction collector can be built for less than $280 USD. An additional graphical user interface (GUI) enables simple programming of the collection methods, requiring no coding experience to operate the collector. The presented fraction collector can be highly customized and use collection vessels as large as 470mL (80x), facilitating repeated collection at a preparatory scale. The use of this platform will increase the reproducibility of scalable and iterative fraction collection methods while removing the cost barrier and allowing for a high degree of customizability.

Reestablishing appropriate tree species is an important step in converting off‐site monocultures into woodlands. Species conversion is often necessary, as off‐site exotic species rarely function like woodland species. However, when off‐site tree species are native, and functionally redundant to woodland species, conversion may be unnecessary. To explore this possibility in the southeastern United States, we reviewed the literature on trait differences among the primary southern pines and qualitatively assessed the effect of their identity at the species and stand‐levels. In this region, woodland restoration focuses on removing loblolly (Pinus taeda) and slash pine (P. elliottii) to reestablish longleaf (P. palustris) or shortleaf pine (P. echinata). Our review found minimal variation among species in understory flammability, fire resistance at maturity, and Red‐cockaded Woodpecker (Leuconotopicus borealis) habitat at the stand‐level. Longleaf and shortleaf pine were generally more resistant to abiotic and pest disturbance at the tree‐level; however, stand‐level differences in wind, drought, and boring insect resistance among southern pines growing in open forests were considered minimal. Retaining loblolly and slash pine will improve stand‐level productivity in the short term, but creates regeneration problems due to low juvenile fire resistance and resilience. Ice resistance and long‐term carbon sequestration will also likely be reduced by retaining loblolly and slash pine. Collectively, these results suggest that southern pine species are generally interchangeable at the stand‐level in woodlands; although woodlands featuring loblolly and slash pine may be less stable in the face of disturbance than those dominated by shortleaf and longleaf pine.

Understanding risk factors associated with reintroductions is important for making informed decisions within an adaptive framework. Biosecurity measures minimizing the risk of the introduction or spread of transmissible diseases are a priority when considering the release of captive-reared wildlife. Eastern indigo snake (EIS; Drymarchon couperi) reintroductions have been occurring in Alabama since 2010 and in Florida since 2017. During this effort the pathogen Cryptosporidium serpentis was detected, affecting several of the captive breeding snakes. Infected snakes were quarantined and removed from breeding efforts, which reduced snakes available for the reintroduction projects. To make informed management decisions about future reintroduction strategies, 155 free-ranging snakes were sampled at the two release sites and a third site in Georgia to evaluate the natural occurrence of C. serpentis. Additionally, 72 free-ranging EIS and other species incidentally encountered throughout the EIS range were tested opportunistically. All snakes sampled at the three focal sites tested negative, but one opportunistically tested EIS from South Florida tested positive. These results indicate that C. serpentis is present in the environment in at least one location, but at low levels. Our results suggest that, pending additional surveillance, C. serpentispositive snakes should not be included in reintroduction efforts, and that maintaining a high level of biosecurity is important in captive breeding programs.

Human land use and climate change have increased forest density and wildfire risk in dry conifer forests of western North America, threatening various ecosystem services, including habitat for wildlife. Government policy supports active management to restore historical structure and ecological function. Information on potential contributions of restoration to wildlife habitat can allow assessment of tradeoffs with other ecological benefits when prioritizing treatments. We predicted avian responses to simulated treatments representing alternative scenarios to inform landscape‐scale forest management planning along the Colorado Front Range. We used data from the Integrated Monitoring in Bird Conservation Regions program to inform a hierarchical multispecies occupancy model relating species occupancy and richness with canopy cover at two spatial scales. We then simulated changes in canopy cover (remotely sensed in 2018) under three alternative scenarios, (1) a “fuels reduction” scenario representing landscape‐wide 30% reduction in canopy cover, (2) a “restoration” scenario representing more nuanced, spatially variable treatments targeting historical conditions, and (3) a reference, no‐change scenario. Model predictions showed areas of potential gains and losses for species richness, richness of ponderosa pine forest habitat specialists, and the ratio of specialists to generalists at two (1 km2 and 250 m2) spatial scales. Under both fuels reduction and restoration scenarios, we projected greater gains than losses for species richness. Surprisingly, despite restoration more explicitly targeting ecologically relevant historical conditions, fuels reduction benefited bird species richness over a greater spatial extent than restoration, particularly in the lower montane life zone. These benefits reflected generally positive species associations with moderate canopy cover promoted more consistently under the fuels reduction scenario. In practice, contemporary forest management is likely to lie somewhere between the fuels reduction and restoration scenarios represented here. Therefore, our results inform where and how active forest management can best support avian diversity. Although our study raises questions regarding the value of including landscape‐scale heterogeneity as a management objective, we do not question the value of targeting finer scale heterogeneity (i.e., stand and treatment level). Rather, our results combined with those from previous work clarify the scale at which targeting structural heterogeneity and historical reference conditions can promote particular ecosystem services.

ABSTRACTBoth fire and predators have strong influences on the population dynamics and behaviour of animals, and the effects of predators may either be strengthened or weakened by fire. However, knowledge of how fire drives or mediates predator–prey interactions is fragmented and has not been synthesised. Here, we review and synthesise knowledge of how fire influences predator and prey behaviour and interactions. We develop a conceptual model based on predator–prey theory and empirical examples to address four key questions: (i) how and why do predators respond to fire; (ii) how and why does prey vulnerability change post‐fire; (iii) what mechanisms do prey use to reduce predation risk post‐fire; and (iv) what are the outcomes of predator–fire interactions for prey populations? We then discuss these findings in the context of wildlife conservation and ecosystem management before outlining priorities for future research. Fire‐induced changes in vegetation structure, resource availability, and animal behaviour influence predator–prey encounter rates, the amount of time prey are vulnerable during an encounter, and the conditional probability of prey death given an encounter. How a predator responds to fire depends on fire characteristics (e.g. season, severity), their hunting behaviour (ambush or pursuit predator), movement behaviour, territoriality, and intra‐guild dynamics. Prey species that rely on habitat structure for avoiding predation often experience increased predation rates and lower survival in recently burnt areas. By contrast, some prey species benefit from the opening up of habitat after fire because it makes it easier to detect predators and to modify their behaviour appropriately. Reduced prey body condition after fire can increase predation risk either through impaired ability to escape predators, or increased need to forage in risky areas due to being energetically stressed. To reduce risk of predation in the post‐fire environment, prey may change their habitat use, increase sheltering behaviour, change their movement behaviour, or use camouflage through cryptic colouring and background matching. Field experiments and population viability modelling show instances where fire either amplifies or does not amplify the impacts of predators on prey populations, and vice versa. In some instances, intense and sustained post‐fire predation may lead to local extinctions of prey populations. Human disruption of fire regimes is impacting faunal communities, with consequences for predator and prey behaviour and population dynamics. Key areas for future research include: capturing data continuously before, during and after fires; teasing out the relative importance of changes in visibility and shelter availability in different contexts; documenting changes in acoustic and olfactory cues for both predators and prey; addressing taxonomic and geographic biases in the literature; and predicting and testing how changes in fire‐regime characteristics reshape predator–prey interactions. Understanding and managing the consequences for predator–prey communities will be critical for effective ecosystem management and species conservation in this era of global change.

Fear of the human 'super predator' has been demonstrated to so alter the feeding behavior of large carnivores as to cause trophic cascades. It has yet to be experimentally tested if fear of humans has comparably large effects on the feeding behavior of large herbivores. We conducted a predator playback experiment exposing white-tailed deer to the vocalizations of humans, extant or locally extirpated non-human predators (coyotes, cougars, dogs, wolves), or non-predator controls (birds), at supplemental food patches to measure the relative impacts on deer feeding behavior. Deer were more than twice as likely to flee upon hearing humans than other predators, and hearing humans was matched only by hearing wolves in reducing overall feeding time gaged by visits to the food patch in the following hour. Combined with previous, site-specific research linking deer fecundity to predator abundance, this study reveals that fear of humans has the potential to induce a larger effect on ungulate reproduction than has ever been reported. By demonstrating that deer most fear the human 'super predator', our results point to the fear humans induce in large ungulates having population- and community-level impacts comparable to those caused by the fear humans induce in large carnivores.