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In response to declining coral populations worldwide, conservation groups are increasingly applying restoration strategies to bolster abundance and diversity, including sexual propagation of corals. Collection and fertilization of coral gametes as well as larval rearing and settlement have been successful. However, post‐settlement stages remain a bottleneck (80–100% mortality), which makes this technique costly to implement at scale. To address this challenge, we compared the survival and colony size of three sexually propagated Caribbean coral species,Diploria labyrinthiformis,Pseudodiploria strigosa, andOrbicella faveolata, reared at three levels of investment: direct outplant to reef, in situ field nursery rearing, and ex situ aquaculture facility rearing. As part of coral sexual propagation work in St. Croix, United States Virgin Islands, recruits were reared for 1 year before being outplanted to reef plots and were monitored annually for three subsequent years. The cost‐effectiveness of each rearing strategy was calculated at each monitoring time point via coral seeding unit yield and cost per seeding unit. Although survival was low at 4 years (0–1.8%), corals reared in the in situ nursery displayed significantly higher survival and therefore lower cost per seeding unit than the other two investment strategies. These results highlight the benefits of an in situ nursery stage to increase long‐term juvenile survival and cost‐effectiveness. The return on investment of corals reared in the in situ nursery suggests that outplanting sexually propagated corals may be a viable restoration strategy; however, the low proportion of corals surviving at 4 years highlights current limitations when outplanting on degraded reefs. 

ABSTRACT Climate warming is especially pronounced in winter and at high latitudes. Warming winters are leading to the loss of lake ice and changing snow cover on lakes. Historically, lake scientists have paid less attention to the ice cover period, leading to data and theory gaps about the role of winter conditions in lake ecosystem function and the consequences of changing winters. Here we use simple models to show that the latitudinal interaction between ice cover duration and light flux seasonality has profound and underappreciated implications for lakes. Our models focus on light and temperature, two key drivers of ecosystem processes. We show that the relative amount of light arriving in lakes during ice cover increases non‐linearly with latitude and that the light climate of high latitude lakes is much more sensitive to changing winter conditions than that of lower latitude lakes. We also demonstrate that the synchronicity between high light and warm temperatures may decrease with latitude, with implications for primary and secondary production. Our results suggest that ice loss may lead to greater relative change to productivity and biotic interactions in higher latitude lakes and also offer several testable predictions for understanding the consequences of climate‐induced changes across latitudinal gradients. 

Abstract This paper deals with the derivation of the mean‐field limit for multi‐agent systems on a large class of sparse graphs. More specifically, the case of non‐exchangeable multi‐agent systems consisting of non‐identical agents is addressed. The analysis does not only involve PDEs and stochastic analysis but also graph theory through a new concept of limits of sparse graphs (extended graphons) that reflect the structure of the connectivities in the network and has critical effects on the collective dynamics. In this article some of the main restrictive hypothesis in the previous literature on the connectivities between the agents (dense graphs) and the cooperation between them (symmetric interactions) are removed. 

Abstract The hot deserts of the southwestern United States are experiencing increased frequency, severity, and duration of drought due to anthropogenic climate change. Plant communities in these deserts differ in composition, specifically the abundance of annual and perennial species, which could differentiate responses among these ecosystems to drought. Thus, identifying how these desert plant communities respond to prolonged, severe drought is critical to assess vulnerability to climate change. We measured the response of herbaceous plant communities to 4 years of experimentally imposed severe drought in Chihuahuan, Sonoran, and Mojave Desert sites in the southwestern US.We imposed year‐round passive rain exclusion treatments with a 66% reduction in ambient rainfall for 4 years at two sites in each of the three US hot deserts. We measured plant species composition and abundance in treatment and control plots during the peak growing season.Vegetative cover increased with seasonal precipitation at all six sites. Species richness and evenness varied in response to drought across all sites over the duration of the experiment. At three of the six sites, species richness increased with seasonal precipitation and at three sites species evenness decreased with seasonal precipitation.In general, we found that community structure was linked to seasonal precipitation more so than cumulative drought in these herbaceous communities of southwestern US deserts, and that these desert communities are highly resilient following prolonged, extreme drought. 

ABSTRACT Water data are evolving rapidly, driven by the expansion of diverse data platforms and the implementation of new policy frameworks. Despite advancements, the utilization of water data by water users remains uncertain. We surveyed 173 water permit holders across New York State to understand what water data are collected and for what purpose across geography, sector, and withdrawal volume. This study reveals that water data primarily serve regulatory purposes and play little role in permittees' operational, sustainability, or risk management decisions. To unlock the full potential of water data for users, we recommend educational initiatives such as training programs for data‐driven assessments, alongside technological advancements like developing web data portals that support risk and impact assessments. These recommendations aim to foster collaboration for navigating the complexities of stressors and achieving a more informed and adaptable approach to water usage. 

Human‐induced changes to the climate and environment have precipitated dramatic declines in abundance and shifts in plant and animal phenologies. These changes have been especially pronounced for migratory species that rely on numerous geographic locations throughout the year. Migratory bird species are notable in the number of species that have experienced both declines in abundance and shifts in phenology over the past 50 years, although the magnitude and direction of changes vary considerably across species. The community‐level impacts of species declines and phenological shifts have been explored in stationary communities, but we know little about the effects of these changes on species relationships during migration seasons when species may interact in ways that influence their route, timing, or success of the journey (e.g., through competition or access to information about resources). Therefore, we assessed the extent to which co‐migrating bird communities have changed over time, and whether changes in species co‐occurrence are associated with changes in abundance or shifts in migration timing. We used over 700,000 records of birds captured at five long‐term migration monitoring stations in eastern North America and found that pairwise species co‐occurrences have changed by as much as 40% over the past 50 years. Changes in co‐occurrence were consistently associated with species‐specific changes in phenology and sometimes associated with changes in abundance. Overall, stopover communities at three sites have significantly changed over the past few decades. Numerous and dramatic changes in co‐occurrence could be affecting the types and frequencies of interspecific interactions like competition and the exchange of social information, transforming the journeys of migratory birds in innumerable ways that could be altering their timing, energy, and safety. 

Abstract Blow flies (Diptera: Calliphoridae) occur worldwide and exhibit a wide range of larval feeding habits, including saprophagy, coprophagy, parasitism and predation. Understanding their biology is critical for medical and veterinary science and ecology. Calliphorids thrive across a range of habitats and exhibit complex life histories, with larvae developing immersed in their food substrate, while adults are free‐living and have diverse feeding strategies. Some species have evolved specialized parasitic associations with vertebrate or invertebrate hosts, which are behaviors with important implications for agriculture and for understanding evolutionary transitions between saprophagy and parasitism. This study presents a comprehensive phylogenetic analysis of the Calliphoridae, utilizing 711 of 736 analysed nuclear genes, using anchored hybrid enrichment, from a global collection of blow flies and their relatives. Our results provide a robust and novel reconstruction of the evolutionary history of this group, pinpointing major transitions in larval feeding habits. We argue that saprophagy evolved independently multiple times from invertebrate parasitic ancestors, with vertebrate parasitism emerging from a number of different feeding strategies. These findings challenge prior hypotheses and offer new insights into the adaptive traits driving trophic specialization and diversification in this group. 

ABSTRACT Siberian boreal forests have experienced increases in fire extent and intensity in recent years, which may threaten their role as carbon (C) sinks. Larch forests (Larixspp.) cover approximately 2.6 million km²across Siberia, yet little is known about the magnitude and drivers of carbon combustion in these ecosystems. To address the paucity of field‐based estimates of fuel load and consumption in Siberian larch forests, we sampled 41 burned plots, one to two years after fire, in Cajander larch (Larix cajanderi) forests in the Republic of Sakha (Yakutia), Russia. We estimated pre‐fire carbon stocks and combustion with the objective of identifying the main drivers of carbon emissions. Pre‐fire aboveground (trees and woody debris) and belowground carbon stocks at our study plots were 3.12 ± 1.26 kg C m⁻²(mean ± standard deviation) and 3.50 ± 0.93 kg C m⁻². We found that combustion averaged 3.20 ± 0.75 kg C m⁻², of which 78% (2.49 ± 0.56 kg C m⁻²) stemmed from organic soil layers. These results suggest that severe fires in Cajander larch forests can result in combustion rates comparable to those observed in North American boreal forests and exceeding those previously reported for other forest types and burning conditions in Siberia. Carbon combustion was driven by both fire weather conditions and landscape variables, with pre‐fire organic soil depth being the strongest predictor across our plots. Our study highlights the need to better account for Siberian larch forest fires and their impact on the carbon balance, especially given the expected climate‐induced increase in fire extent and severity in this region. 

Abstract The Amazon River exports over 10% of the global riverine dissolved organic carbon (DOC) flux to the ocean. However, several downstream clearwater tributaries, such as the Tapajós River, are typically not included in these measurements, omitting a crucial part of the Amazon carbon cycle. This study investigated near‐monthly DOC and dissolved organic matter (DOM) composition via optical, fluorescence spectroscopy, and ultra‐high resolution mass spectrometry (FT‐ICR MS) of the Tapajós River for 8 years (2016–2024) to better understand patterns and drivers of potential organic carbon export to the lower Amazon River. DOM composition and DOC export were driven by the seasonal flood pulse of the Tapajós River, exporting aromatic terrestrial DOM from the watershed during high discharge and internally produced algal or microbial DOM during dry periods. On average, we report that the Tapajós River exports 1.38 Tg DOC annually to the downstream Amazon mixing zone, representing an amount of DOC exported by other major world rivers such as the Yukon or Mekong River. Furthermore, organic carbon export varied interannually with less DOC exported during dry El Niño events and more algal‐derived DOM exported during bloom periods. Finally, as grassland and cropland landcover increased over the study period, we observed an average decrease in aromatic DOM and an increase in microbially processed fluorophores. Our study suggests that temperature, precipitation, and anthropogenic land use changes in clearwater rivers will impact carbon export across the lower Amazon River network. 

ABSTRACT Mixed‐species forestry is a promising approach to enhance productivity, increase carbon sequestration, and mitigate climate change. Diverse forests, composed of species with varying structures and functional trait profiles, may have higher functional and structural diversity, which are attributes relevant to a number of mechanisms that can influence productivity. However, it remains unclear whether the context‐dependent roles of functional identity, functional diversity, and structural diversity can lead to a generalized understanding of tree diversity effects on stand productivity. To address these gaps, we analyzed growth data from 83,600 trees from 89 species across 21 young tree diversity experiments spanning five continents and three biomes. Results revealed a positive saturating relationship between tree species richness and stand productivity, with reduced variability in growth rates among more diverse stands. Structural equation modeling demonstrated that functional diversity mediated the positive effects of species richness on productivity. We additionally report a negative relationship between structural diversity and productivity, which decreased with increasing species richness. When partitioning net diversity effects, we found that selection effects played a dominant role in driving the overall increase in productivity in these predominantly young stands, contributing 77% of the net diversity effect. Selection effects increased with diversity in wood density. Furthermore, acquisitive species with lower wood density and higher leaf nitrogen content had higher productivity in more diverse stands, while conservative species showed neutral to slightly negative responses to species mixing. Together, these results suggest that combining acquisitive with conservative species allows acquisitive species to drive positive selection effects while conservative species tolerate competition. Thus, contrasting resource‐use strategies can enhance productivity to optimize mixed‐species forestry, with potential for both ecological and economic benefits.