Frontiers in Ecology and the Environment最新文献

The world's rangelands and drylands are undergoing rapid change, and consequently are becoming more difficult to manage. Big data and digital technologies (digital tools) provide land managers with a means to understand and adaptively manage change. An assortment of tools—including standardized field ecosystem monitoring databases; web-accessible maps of vegetation change, production forecasts, and climate risk; sensor networks and virtual fencing; mobile applications to collect and access a variety of data; and new models, interpretive tools, and tool libraries—together provide unprecedented opportunities to detect and direct rangeland change. Accessibility to and manager trust in and knowledge of these tools, however, have failed to keep pace with technological advances. Collaborative adaptive management that involves multiple stakeholders and scientists who learn from management actions is ideally suited to capitalize on an integrated suite of digital tools. Embedding science professionals and experienced technology users in social networks can enhance peer-to-peer learning about digital tools and fulfill their considerable promise.

Climate change is altering fire regimes and post-fire conditions, contributing to relatively rapid transformation of landscapes across the western US. Studies are increasingly documenting post-fire vegetation transitions, particularly from forest to non-forest conditions or from sagebrush to invasive annual grasses. The prevalence of climate-driven, post-fire vegetation transitions is likely to increase in the future with major impacts on social–ecological systems. However, research and management communities have only recently focused attention on this emerging climate risk, and many knowledge gaps remain. We identify three key needs for advancing the management of post-fire vegetation transitions, including centering Indigenous communities in collaborative management of fire-prone ecosystems, developing decision-relevant science to inform pre- and post-fire management, and supporting adaptive management through improved monitoring and information-sharing across geographic and organizational boundaries. We highlight promising examples that are helping to transform the perception and management of post-fire vegetation transitions.

While hiking in the Carolinas of the southeastern US, I was baffled by curious strands emerging from the forest floor, covered in fresh snow. Later, I learned that I had observed “needle ice” (see image), a form of ice that is related to a different phenomenon known as “hair ice”.

Hair ice, also called ice wool or frost beard, originates from the fungus Exidiopsis effusa. In 1918, Alfred Wegener (who earlier had proposed continental drift theory) suggested a fungus as the suspected source of the delicate strands of hair ice. However, E effusa was not identified as the responsible fungal agent until 2015 by Hofmann et al., whose seminal work (Biogeosciences 2015; doi.org/10.5194/bg-12-4261-2015) provides an excellent review of discoveries related to hair ice, including: (i) E effusa's gossamer-like hair ice is fragile (disintegrating if handled) and ephemeral (lasting for hours or a few days under ideal conditions); (ii) E effusa emerges only from decomposing branches of broadleaf trees and in temperatures at or below 0°C; (iii) the fungus has been reported in multiple countries between the latitudes of 45° and 55°N; (iv) the mycelium of E effusa appears to provide the supporting structure for the hairs of ice, which have a diameter of around only 0.02 mm; (v) hair ice forms from a dense concentration of mycelium, drawing water from the porous substrate of the wood; (vi) a recrystallization inhibitor is likely responsible for the stabilization of the fine hairs; and (vii) E effusa's fruiting body typically appears macroscopically weeks later on the wood surface as a thin, white rot coating.

The specimen featured in the accompanying photograph is needle ice. Often mistaken for hair ice, needle ice is a related ice type that grows from soil instead of wood, has slightly stiffer needles, and forms columns (Mätzler C, Wagner G, Preuss G, and Hofmann D. 2013. Enlightening the mystery of hair ice. IAP Research Report 2013-01-MW. Bern, Switzerland: Institute of Applied Physics, University of Bern). The source of needle ice formations is not associated with a fungus; rather, it is groundwater, which rises to the surface by capillary action and freezes. The phenomenon occurs in areas that experience frequent thaw–freeze cycles (Cold Regions Sci Technol 1988; doi.org/10.1016/0165-232X(88)90076-6). Needle ice is also recognized as a cause of soil disturbance, though its unusual appearance, like that of hair ice, is especially captivating.

Special thanks to Diana Hofmann for help with identification.

Ecologists have been using AI in research for decades (machine-learning is a more boring name for it), and today it is not uncommon for ecology graduate students to run their statistics using iterative, problem-solving AI algorithms. At its core, AI-based prediction is simply an automated version of the scientific method, designed to be an iterative learning process that becomes more refined with each iteration based on feedback and experience. In machine learning, selection for an optimized solution occurs with every iteration, somewhat similar to how natural selection operates on each generation of a species. With each iteration, the model attempts to minimize differences between its output and what it was trained to believe should be the “correct” output. Ultimately, humans control the inputs and impose artificial selection pressures (such as model parameters, thresholds, and goals for the training) that drive evolution of the outputs in a desired direction. A relevant question is whether humans can sensibly guide this evolution in a manner that parallels evolution and adaptation by natural selection.

Those worried about AI fear that we humans will end up on the wrong side of this selection process, in a zero-sum game between biology and technology. But the reality is that selection is driving biology and computing more closely together, toward an obligate symbiosis rather than a divergence. One could argue that this coevolution has already commenced and that we are already part human, part machine. For example, many of us have instant and unrestricted access to the vast knowledge of the internet via smartphones in the palms of our hands. It is relatively easy to imagine that humans will become more integrated with and dependent on AI in the future, because AI can help humans optimize solutions for complex problems (whether for morally good or bad reasons). If a hypothetical tipping point is crossed in which AI surpasses human intelligence and gains some degree of autonomy and sentience, it is unlikely that AI will annihilate humans, because that would be akin to attacking itself.

Instead, the more likely risk is that humans are becoming, and will continue to become, something new. Who better to understand the limits than ecologists, with their understanding of the fundamental principles of adaptation and evolution? In The Origin of Species, Darwin described natural selection as a process analogous to selective breeding in domesticated pigeons and horses, and this analogy can be further generalized to our coevolution with AI. If humanity becomes entangled within a mutualistic association with AI, its outputs and capabilities will be refined and its early forms will eventually either become extinct or morph into better adapted versions. This evolution is likely to be slow, though punctuated by moments of rapid and drastic change.

Are there risks? Of course, but they are more likely of the variety that we currently fa

While conducting field research on plants in China's western Sichuan Plateau during July 2022, we observed the perennial herb Przewalskia tangutica (Solanaceae) with pocket-like green bracts (hereafter, “green pockets” or simply “pockets”). Each plant had multiple green pockets, and each green pocket contained a single fruit along its interior base. Interestingly, we found that the pocket would naturally fall off the plant once its fruit was mature. Then, as the pocket—now disconnected from its plant—gradually desiccated, it became so light that it could easily be blown far away by the wind. A few days after gaining its independence, the pocket almost entirely decayed, leaving only a mesh-like framework of veins, thereby allowing the seeds to escape. This finding suggests that the pocket plays a role in seed dispersal and promotes the spread of P tangutica, an imperiled species found at high elevations and subject to overharvesting due to its medicinal properties. However, some questions remain unanswered. Because each pocket has a small mouth-like opening at its top, if rain falls into a pocket, does it affect fruit and seed development? Does the green pocket contribute resources (such as carbon and energy) to fruit and seed development through photosynthesis? Was the evolution of the pocket driven by harsh physical conditions (such as low temperatures, ultraviolet radiation from intense sunlight, or heavy rains) on the plateau? Does the pocket provide protection against potential seed predators?

Sound plays a key role in ecosystem function and is a defining part of how humans experience nature. In the seminal book Silent Spring (Carson 1962), Rachel Carson warned of the ecological and environmental harm of pesticide usage by envisioning a future without birdsong. Soundscapes, or the acoustic patterns of a landscape through space and time, encompass both biological and physical processes (Pijanowski et al. 2011). Yet, they are often an underappreciated element of the natural world and the ways in which it is perceived. Scientists are only beginning to quantify changes to soundscapes, largely in response to anthropogenic sounds, but soundscape alteration is likely linked to many dimensions of global change. For example, invasive non-native species (hereafter, invasive species) are near-ubiquitous members of ecosystems globally and threaten both natural and managed ecosystems at great expense. Their impacts to soundscapes may be an important, yet largely unknown, threat to ecosystems and the human and economic systems they support.

The proper functioning of sound-based cues depends on the overall soundscape of an environment, which is determined by a range of biological and physical factors, many of which may be influenced by invasive species. To date, research on the effects of invasive species on sound focuses primarily on specific invasive species that make sounds or the loss of sound-making native biota (Hopkins et al. 2022) rather than on the soundscape overall.

For instance, invasive amphibians, such as the American bullfrog (Lithobates catesbeianus), can dominate a soundscape, resulting in alterations to vocalizations, increased energy expenditure, and reduction in breeding success of native amphibians (Both and Grant 2012). The arrival of sound-making invasive species may thus increase the overall diversity of a soundscape, but with negative consequences for native species. Alternatively, invasive species may eliminate the most dominant and recognizable parts of soundscapes. The invasive brown tree snake (Boiga irregularis) has driven the functional extinction of an entire avian community, resulting in Guam's “silent forests” with cascading effects on ecosystem function (Rogers et al. 2017). In some cases, invasive species may change soundscapes by driving community turnover and diversity through environmental change. Through alterations in the physical environment, invasive beavers (Castor canadensis) in South America shifted avian community composition, subsequently changing the soundscape (Francomano et al. 2021). Even when beaver dams were removed, the original composition of the avian community, and resulting soundscape, remained altered (Francomano et al. 2021).

As Hopkins et al. (2022) noted in their review of contemporary studies on

In mixed-species groups, moray eels (Muraenidae) can function as focal species, hunting for prey within the deep interstices of reefs and, in the process, flushing out potential prey that are then vulnerable to attack by the moray's companions. On 7 December 2021, we observed an unusually large mixed-species hunting group of piscivorous fishes, composed of 26 bluefin trevally (Caranx melampygus), two black jack (Caranx lugubris), and three whitetip reef sharks (Triaenodon obesus) following a single yellow-edged moray (Gymnothorax flavimarginatus) at dusk along the deep (21 m) reef–sand margin off Manuelita Island in Isla del Coco National Park (Pacific Costa Rica). The moray entered a crevice (indicated by the arrow, in the top image) in an isolated coral framework while the primary hunting group circled the vicinity in both clockwise and counterclockwise directions, and the sharks entered and exited the crevice for about seven minutes before dispersing with only the moray remaining. The association of the hunting group may have enabled its members to encounter disturbed prey and then to provoke the moray to continue swimming and hunting, and thus flush out additional prey at other nearby locations. Current understanding remains limited for how predators determine trade-offs for hunting in groups versus individually, how predators share information related to group formation and dissolution, and what the outcomes of such behaviors are in terms of individual fitness. How short-term mutualisms such as these shape the functional relationships between predators and prey in fish communities is an area in need of enhanced attention, given the existing threats to large predators from overfishing and the need to conserve species interactions as a component of ecosystem management.

Future dynamics of biological invasions are highly uncertain because they depend on multiple social–ecological drivers. We used a scenario-based approach to explore potential management options for invasive species in Europe. During two workshops involving a multidisciplinary team of experts, we developed a management strategy arranged into 19 goals relating to policy, research, public awareness, and biosecurity. We conceived solutions for achieving these goals under different plausible future scenarios, and identified four interrelated recommendations around which any long-term strategy for managing invasive species can be structured: (1) a European biosecurity regime, (2) a dedicated communication strategy, (3) data standardization and management tools, and (4) a monitoring and assessment system. Finally, we assessed the feasibility of the management strategy and found substantial differences among scenarios. Collectively, our results indicate that it is time for a new strategy for managing biological invasions in Europe, one that is based on a more integrative approach across socioeconomic sectors and countries.

Managing ecosystems to sequester soil carbon requires a thorough understanding of complex soil processes. Here, we integrate these soil processes through the metaphor of a game—one that moves through multiple dimensions (from macro-aggregates to micropores and clay particles) and scales (from centimeters to nanometers) of the soil. The rules of the game are based on current understanding of soil carbon persistence, which differs from the classic humus concept of molecular complexity. The game's objective is to win points, by keeping “tokens” (plant-derived organic compounds) within the soil organic matter for as long as possible. The game begins when tokens enter different “pool-levels” (plant litter, particulate organic matter, dissolved organic matter, and mineral-associated organic matter) of the soil, either directly or after metabolic transformation by soil biota. Points are lost through either respiration by soil biota or leaching. We invite readers to play this game and explore different natural ecosystems and land-use scenarios to better comprehend complex soil processes.

Information on natural resource exploitation is vital for conservation but scarce in developing nations, which encompass most of the world and often lack the capacity to produce it. A growing approach to generate information about resource use in the context of developing nations relies on surveys of resource users about their recollections (recall) of past harvests. However, the reliability of harvest recalls remains unclear. Here, we show that harvest recalls can be as accurate to data collected by standardized protocols, despite that recalls are variable and affected by the age of the recollecting person and the length of time elapsed since the event. Samples of harvest recalls permit relatively reliable reconstruction of harvests for up to 39 years in the past. Harvest recalls therefore have strong potential to inform data-poor resource systems and curb shifting baselines around the world at a fraction of the cost of conventional approaches.