Joshua H. Daskin

Applying science to conservation requires deliberate planning and action infrequently taught in academic settings. To illustrate impactful analysis and science communication, we describe scientific activities targeting the needs of land trusts, NGOs, landowners, and government agencies working to conserve the Florida Wildlife Corridor (“Corridor”). This 7.2 million hectare area is prioritized for habitat connectivity conservation in the US state of Florida. Our activities are built on decades of science guiding Florida land conservation. We quantified threats (e.g., average of over 14,000 ha of development/year from 2001 to 2019) and socio‐ecological benefits of Corridor conservation, prioritized yet‐to‐be‐conserved Corridor areas, produced and shared a new statewide connectivity model, and convened groups to identify campaign science needs. The new connectivity model—the Florida Circuit Model—supported the geography of the Corridor, as designated, and facilitates local (10 km radius, or less) conservation planning. Our efforts have contributed to allocation of over $2 billion for land conservation and the permanent protection of over 82,000 ha within the Corridor by state agencies from June 2021 to March 2024. Targeting science to outreach and policy, planning, and management decisions can motivate public, media, researcher, and government support for land conservation, improve conservation interventions, and attract research funding.

Demographic modelling can reveal options for improved conservation management, especially for rare or long-lived species not amenable to experimentation. Sturgeon (Acipenseridae) include many such species, endangered by demand for caviar, their unfertilized roe, and by dams blocking their migrations. Restocking of sturgeon populations with farm-raised individuals has probably prevented extinctions and widespread extirpations of some species, but it has rarely led to true recovery in Eurasia, given ongoing harvest. We used modified Leslie matrix models to test whether restocking with year-old juveniles instead of weeks-old fry could recover the critically endangered Amur sturgeon (Acipenser schrenckii), endemic to the Amur River basin along the Russia–China border. Without restocking, or even releasing an expert-recommended annual volume of young fry (10 million), we project that three of four Amur sturgeon populations will be nearly extirpated within 30 years. However, restocking with 5% as many (500 000) year-old juveniles annually could grow three populations (currently 0–425 mature females) and slow declines in another so that each has over 6400 mature females within 30 years. Retooling stocking efforts to use fewer juveniles that survive at higher rates than do small fry could buy time to reduce harvesting pressure on Amur sturgeon and for other related sturgeon species.

Tree cover differentiates forests from savannas and grasslands. In tropical floodplains, factors differentiating these systems are poorly known, even though floodplains cover 10% of the tropical landmass. Seasonal inundation potentially presents trees with both challenges (soil anoxia) and benefits (moisture and nutrient deposition), the relative importance of which may depend on ecological context, e.g. if floods alleviate water stress more in more arid ecosystems. Here, we use remotely sensed data across 13 large tropical and sub-tropical floodplain ecosystems on five continents to show that climatic water balance (i.e. precipitation—potential evapotranspiration) strongly increases floodplain tree cover in interaction with flooding, fire and topography. As predicted, flooding increases tree cover in more arid floodplains, but decreases tree cover in climatically wetter ones. As in uplands, frequent fire reduced tree cover, particularly in wet regions, but—in contrast with uplands—lower elevation and sandier soils decreased tree cover. Our results suggest that predicting the impacts of changing climate, land use and hydrology on floodplain ecosystems depends on considering climate-disturbance interactions. While outright wetland conversion proceeds globally, additional anthropogenic activities, including alteration of fire frequencies and dam construction, will also shift floodplain tree cover, especially in wet climates.

Ecosystems feel war's effects: War ravages human lives and landscapes, but nonhuman victims are no less affected. The Mozambican Civil War resulted in the rapid decline of predators in Gorongosa National Park and led to a trophic cascade that shifted prey behaviors and plant communities. Atkins et al. monitored this shift and found that the absence of wild dogs and leopards resulted in a change in habitat use and plant consumption by bushbuck, which are forest-dwelling antelopes. Experiments further showed that changes in prey behavior were reversible when signs of predator activity were introduced, supporting the impact of the predator loss. These results confirm patterns seen elsewhere and go further in providing mechanistic detail about the importance of the “landscape of fear” perceived by prey animals. Science , this issue p. 173

It is well known in ecology, evolution and medicine that both the nature (commensal, parasitic and mutualistic) and outcome (symbiont fitness, survival) of symbiotic interactions are often context-dependent. Less is known about the importance of context-dependence in symbioses involved in wildlife disease. We review variable symbioses, and use the amphibian disease chytridiomycosis to demonstrate how understanding context-dependence can improve the understanding and management of wildlife diseases. In chytridiomycosis, the host–pathogen interaction is context-dependent; it is strongly affected by environmental temperature. Skin bacteria can also modify the interaction; some bacteria reduce amphibians' susceptibility to chytridiomycosis. Augmentation of protective microbes is being considered as a possible management tool, but informed application of bioaugmentation requires understanding of how the interactions between host, beneficial bacteria and pathogen depend upon environmental context. The community-level response of the amphibian skin microbiota to environmental conditions may explain the relatively narrow range of environmental conditions in which past declines have occurred. Environmental context affects virulence and the protection provided by mutualists in other host–pathogen systems, including threatened bats and corals. Increased focus on context-dependence in interactions between wildlife and their symbionts is likely to be crucial to the future investigation and management of emerging diseases of wildlife.

Environmental conditions can alter the outcomes of symbiotic interactions. Many amphibian species have declined due to chytridiomycosis, caused by the pathogenic fungus Batrachochytrium dendrobatidis (Bd), but many others persist despite high Bd infection prevalence. This indicates that Bd's virulence is lower, or it may even be a commensal, in some hosts. In the Australian Wet Tropics, chytridiomycosis extirpated Litoria nannotis from high-elevation rain forests in the early 1990 s. Although the species is recolonizing many sites, no population has fully recovered. Litoria lorica disappeared from all known sites in the early 1990 s and was thought globally extinct, but a new population was discovered in 2008, in an upland dry forest habitat it shares with L. nannotis. All frogs of both species observed during three population censuses were apparently healthy, but most carried Bd. Frogs perch on sun-warmed rocks in dry forest streams, possibly keeping Bd infections below the lethal threshold attained in cooler rain forests. We tested whether short-term elevated temperatures can hamper Bd growth in vitro over one generation (four days). Simulating the temperatures available to frogs on strongly and moderately warmed rocks in dry forests, by incubating cultures at 33°C for one hour daily, reduced Bd growth below that of Bd held at 15°C constantly (representing rain forest habitats). Even small decreases in the exponential growth rate of Bd on hosts may contribute to the survival of frogs in dry forests.