Frontiers in Ecology and the Environment最新文献

“When you can't breathe, nothing else matters.”—slogan of The American Lung Association

The world's waters are losing oxygen, and we should be very concerned.

In 2017, Denise Breitburg, Lisa Levin, and I wrote a guest editorial for this column about ocean deoxygenation—the loss of dissolved oxygen in our oceans, estuaries, and coastal zones. At the time, deoxygenation was little known among many scientists, let alone the general public or policy makers, except as related to eutrophication. We pointed out that although many low oxygen events are tied to sewage pollution and agricultural runoff, deoxygenation is increasingly recognized as a climate-driven problem, affecting even waters without excess nutrients.

2017 was the year when we learned that the oceans had lost ~2% of their oxygen inventory since 1960. Then in 2018, scientists led by Denise and Lisa published a groundbreaking synthesis of what we then knew about coastal “dead zones” and oxygen minimum zones (OMZs), those vast regions of the open ocean where oxygen depletion occurs naturally, which are expanding due to the physics of warming on ocean circulation and ventilation. And in 2019, the IUCN published a summary volume on ocean deoxygenation, which was featured at that year's UN Climate Change Conference (COP25). These works were supported by a UNESCO–Intergovernmental Oceanographic Commission working group, the Global Ocean Oxygen Network (GO₂NE), whose mission is to promote awareness, stimulate research, and provide advice to policy makers on all aspects of ocean deoxygenation.

Currently, efforts are underway to produce an open-access and community-driven Global Ocean Oxygen Database and Atlas (GO₂DAT), to make the growing volume of coastal and open ocean data accessible for displays and analyses. This will be part of the Global Ocean Oxygen Decade, a program within the UN Ocean Decade, and should help us with a better understanding of where problem areas are happening.

But deoxygenation is not limited to oceans: inland water bodies are also losing oxygen, due to a combination of warming, elevated organic matter loading from increased precipitation, longer seasonal stratification, and the attendant impacts of human population growth. In a survey of nearly 400 temperate lakes and reservoirs between 1980 and 2017, Stephen Jane and colleagues reported that surface waters lost >5%, and hypolimnions >18%, of their oxygen. Even rivers are deoxygenating, despite their flowing nature; Penn State's Wei Zhi and colleagues discovered that 70% of 580 rivers surveyed lost oxygen.

Colleagues of mine working in the Adirondack Mountains of New York are concerned about oxygen-related threats to coldwater fishes. Thermal refugia in Adirondack lakes are shrinking as hypoxic/anoxic periods extend longer into the fall. And in New York's Hudson River estuary, 28 years of high-resolution, continuous monito

Human development and population growth are placing immense pressure on natural ecosystems, necessitating the establishment of a balance between development and biodiversity preservation. Citizen science may serve as a valuable resource for monitoring biodiversity and informing decision-making processes, but its use has not been investigated within the realm of environmental review. We sought to quantify the extent to which citizen science data are currently being used, mentioned, or suggested in environmental impact statements (EISs) by analyzing more than 1300 EISs produced under the US National Environmental Policy Act. Among the sampled EISs, we found increasing incorporation of citizen science within the environmental review process, with 40% of EISs in 2022 using, mentioning, or suggesting use of such information, as compared with just 3% in 2012. Citizen science offers substantial potential to enhance biodiversity monitoring and conservation efforts within environmental review, but numerous considerations must be broadly discussed before citizen science data can be widely adopted.

Combating climate change and achieving the UN Sustainable Development Goals (SDGs) are two important challenges facing humanity. Natural climate solutions (NCSs) can contribute to the achievement of these two commitments but can also generate conflicting trade-offs. Here, we reviewed the literature and drew on expert knowledge to assess the co-benefits of and trade-offs between 150 SDG targets and NCSs within 12 selected ecosystems. We demonstrate that terrestrial, coastal, and marine NCSs enable the attainment of different sets of SDG targets, with low redundancy. Implementing NCSs in various ecosystems would therefore maximize achievement of SDG targets but would also induce trade-offs, particularly if best practices are not followed. Reliance on NCSs at large scales will require that these trade-offs be taken into consideration to ensure the simultaneous realization of positive climate outcomes and multiple SDG targets for diverse stakeholders.

Conservation conflicts are arguably one of the most complex challenges facing global biodiversity conservation. Social–ecological systems (SES) science is uniquely positioned to address this challenge. However, there is scarce scientific evidence to demonstrate that global empirical research on conservation conflicts has been conducted through an SES lens. We systematically mapped the scientific literature on a global scale to understand the landscape of conservation conflict research addressed from an SES perspective. Our mapping and subsequent analysis of 865 studies over the past three decades revealed that most research has been conducted in the US and Mexico, with conflicts arising from decisions over land use and ocean management as the most frequently studied. Of the analyzed studies, the most influential SES frameworks used were ascribed to three key publications. Our findings highlight the relative scarcity of research on conflicts in biodiversity hotspots of the Middle East, the Caribbean, and North and Central Africa.

Drones are increasingly being used to monitor, film, and survey birds. Many studies also report that, as compared to traditional methods such as ground counts or helicopter surveys, drones can reduce bird disturbance. Yet, best practices on how drones should be flown to reduce adverse behavior are usually species-specific and context-dependent, and are therefore often difficult to apply to new management scenarios. Here, we reviewed 149 avian studies, all of which involved drone use and were published in peer-reviewed scientific journals, and conducted a phylogenetically informed meta-analysis to better understand which factors can help to reduce flushing response in birds. The distance between the drone and the bird, drone speed, bird breeding status, and species size all strongly influenced the chances of a flushing response. Finally, we provide drone operational guidelines that are specific to and applicable across both drone type and taxa of interest.

Cleaning symbiosis is an ecological phenomenon characterized by a mutually beneficial relationship between two species, where one individual (known as the cleaner) removes external parasites, debris, or other unwanted material from the body of the host (referred to as the client). One remarkable example of cleaning symbiosis involves the interaction between birds and capybaras, as shown by the photograph. Capybaras (Hydrochoerus hydrochaeris) are large rodents that inhabit wetlands, such as the Brazilian Pantanal, where they are exposed to numerous ectoparasites, including ticks and lice. In these settings, certain bird species, such as the cattle tyrant (Machetornis rixosa), take on the role of cleaners by landing on the capybara's body, picking the parasites, and consuming them. Interestingly, this cleaning symbiosis is not merely a one-way interaction. Capybaras also play an active role by lying on the ground and exposing their heads, backs, and bellies, thereby allowing the birds easy access to body parts that would not be reached otherwise (Biota Neotrop 2010; https://doi.org/10.1590/S1676-06032010000100028).

Changing climatic conditions are increasing overstory tree mortality in forests globally. This restructuring of the distribution of biomass is making already flammable forests more combustible, posing a major challenge for managing the transition to a lower biomass state. In western US dry conifer forests, tree density resulting from over a century of fire-exclusion practices has increased the risk of high-severity wildfire and susceptibility to climate-driven mortality. Reducing dead fuel loads will require new approaches to mitigate risk to the remaining live trees by preparing forests to withstand future wildfire. Here, we used data from the Teakettle Experimental Forest in California to evaluate different prescribed fire burn frequencies and their impact on accumulated dead fuels after a 4-year drought. Increasing burn frequency could reduce surface fuel build-up but comes with additional challenges that will require creativity and experimentation to overcome.

Local-scale environmental justice studies of freshwaters have found that marginalized populations are more likely than others to be burdened with poor-quality waters. However, studies have yet to examine whether monitoring data are sufficient to determine the generality of such results at the national scale. We analyzed racial and ethnic community composition surrounding lakes and the presence of one-time and long-term (≥15 years) water-quality data across the conterminous US. Relative to lakes in White and non-Hispanic communities, lakes in communities of color and Hispanic communities were three times less likely to be monitored at least once. Moreover, as compared to lakes in White communities, lakes in communities of color were seven times less likely to have long-term monitoring data; similarly, as compared to lakes in non-Hispanic communities, lakes in Hispanic communities were nineteen times less likely to have long-term monitoring data. Given this evidence, assessing the current water quality of and temporal changes in lakes in communities of color and Hispanic communities is extremely difficult. To achieve equitable management outcomes for people of all racial and ethnic backgrounds, freshwater monitoring programs must expand their sampling and revise their designs.

Transformative change is needed to align common small-scale ecological restoration approaches with expectations to restore millions of hectares of degraded lands globally. Currently, most restoration projects target small areas using costly manual methods that cannot be scaled up to meet global commitments. We propose that a judicious integration of agricultural practices into ecological restoration offers an opportunity to address this issue. This transformative process relies on three sequential and interconnected steps: (1) ensure that sufficient land is truly available for restoration; (2) compensate for the loss of agricultural production, income, or land value to encourage landholders to opt for restoration; and (3) develop scalable, affordable, and effective methods for restoring native ecosystems across the pledged hundreds of millions of hectares to deliver benefits to both nature and people. Large-scale terrestrial restoration will require incorporating agronomic practices into the restoration toolbox to go beyond vague, ambitious promises and wishful thinking.