Acevedo, M. A., Beaudrot, L., MeléndezAckerman, E. J., Tremblay, R. L., & Shefferson, R. (2020). Local extinction risk under climate change in a neotropical asymmetrically dispersed epiphyte. J Ecol, 108(4), 1553–1564.
Abstract: The long-term fate of populations experiencing disequilibrium conditions with their environment will ultimately depend on how local colonization and extinction dynamics respond to abiotic conditions (e.g. temperature and rainfall), dispersal limitation and biotic interactions (e.g. competition, facilitation or interactions with natural enemies). Understanding how these factors influence distributional dynamics under climate change is a major knowledge gap, particularly for small ranged and dispersal-limited plant species, which are at higher risk of extinction. Epiphytes are hypothesized to be particularly vulnerable to climate change and we know little about what drives their distribution and how they will respond to climate change. To address this issue, we leveraged a 10-year dataset on the occupancy dynamics of the endemic orchid Lepanthes rupestris to identify the drivers of local colonization and extinction dynamics and assess the long-term fate of this population under multiple climate change scenarios.
We compared 290 dynamic occupancy models in their ability to predict the colonization and extinction dynamics of a L. rupestris metapopulation. The model set predicted colonization-extinction dynamics as a function of asymmetric patch connectivity, moss area, elevation, temperature (minimum, maximum and variability) and/or rainfall.
The best model predicted that local colonization increases with increasing asymmetric patch connectivity but decreases as minimum temperature and maximum temperature variability increase. The best model also predicted that local extinction increases with increasing variability in maximum temperature. Negative effects were more severe in smaller patches.
Synthesis. Overall, our results demonstrate the role of asymmetric connectivity, climate and interactions with moss area as drivers of colonization and extinction dynamics. Moreover, our results suggest that asymmetrically dispersed epiphytes may struggle to persist under climate change because their limited connectivity may not be enough to counterbalance the negative effects of increasing mean or variability in temperature.
|
|
Cacciapaglia, C., & van Woesik, R. (2018). Marine species distribution modelling and the effects of genetic isolation under climate change. J Biogeogr, 45(1), 154–163.
|
|
Drury, C., Paris, C. B., Kourafalou, V. H., & Lirman, D. (2018). Dispersal capacity and genetic relatedness in Acropora cervicornis on the Florida Reef Tract. Coral Reefs, 37(2), 585–596.
|
Feeley, K. J., Silman, M. R., & Franklin, J. (2016). Disappearing climates will limit the efficacy of Amazonian protected areas. Diversity Distrib., 22(11), 1081–1084.
Abstract: Amazonian forests support high biodiversity and provide valuable ecosystem services. Unfortunately, these forests are under extreme pressure from land use change and other anthropogenic disturbances. A recent study combined data from an Amazon-wide network of forest inventory plots with spatially explicit deforestation models to predict that by 2050, 36% or 57% of species will be 'globally threatened', as defined by IUCN Red List criteria, due to deforestation under Increased-Governance or Business-As-Usual scenarios, respectively. It was also predicted that the number of threatened species will drop by 29-44% if no deforestation occurs within protected areas. However, even the best-protected areas of the Amazon may still be susceptible to the effects of climate change and rising temperatures. To illustrate the potential dangers of climate change for Amazonian parks, we calculated the percentage of land area within all officially designated protected areas of tropical South America that will or will not have future temperature analogs under various scenarios of temperature change and park connectivity. We show that depending on the rate of warming and degree of connectivity, about 19-67% of protected areas will not have any temperature analogs in the near future (2050s). These results help to emphasize that protected areas are not immune to the effects of climate change and that large portions of Amazonian protected areas include 'disappearing climates'. In the face of these disappearing climates, the biggest determinant of many species' extinction risks may be their ability to migrate through non-protected habitats.
|
Holstein, D. M., Paris, C. B., Vaz, A. C., & Smith, T. B. (2016). Modeling vertical coral connectivity and mesophotic refugia. Coral Reefs, 35(1), 23–37.
Abstract: Whether mesophotic reefs will behave as refugia for corals threatened by global climate change and coastal development depends on vertical exchange of larvae between diverse habitats. Here we use a biophysical model of larval dispersal to estimate vertical connectivity of a broadcasting (Orbicella faveolata) and a brooding (Porites astreoides) species of coral in the US Virgin Islands. Modeling predicts subsidy to shallow areas by mesophotic larvae of both species based on local hydrology, adult reproductive characteristics, larval traits, and a wide range of scenarios developed to test depth-sensitive factors, such as fertilization rates and post-settlement survivorship. In extreme model scenarios of reduced fertilization and post-settlement survivorship of mesophotic larvae, 1-10 % local mesophotic subsidy to shallow recruitment is predicted for both species, which are demographically significant. Although direct vertical connectivity is higher for the broadcaster, the brooder demonstrates higher local multigenerational vertical connectivity, which suggests that local P. astreoides populations are more resilient than those of O. faveolata, and corroborates field studies. As shallow habitat degrades, mesophotic-shallow subsidy is predicted to increase for both species. This study is the first of its kind to simulate larval dispersal and settlement between habitats of different depths, and these findings have local, regional, and global implications for predicting and managing coral reef persistence in a changing climate.
|
Kiskaddon, E., Kiskaddon E, Chernicky, K., Chernicky K, Bell, S., & Bell S. (2019). Resource use by and trophic variability of Armases cinereum (Crustacea, Brachyura) across human-impacted mangrove transition zones. PLoS One, 14(2), e0212448.
Abstract: In Florida, resource use patterns by Armases cinereum (Armases), a highly abundant crab in coastal habitats, may serve as important indicators of habitat condition. Here we investigated feeding patterns of Armases in coastal palm scrub forest to intertidal mangrove forest transition zones (transitions) as well as the relationship between habitat disturbance and Armases' trophic position across three pairs of geographically separated populations in Tampa FL, USA. Each pair of sites represented an unmodified "natural" location as well as a "disturbed" location lacking upland terrestrial palm scrub forested habitat. Laboratory experiments established a baseline understanding of feeding preference of Armases offered strictly mangrove material as well as sources abundant at the transition. In-situ feeding behavior was examined using MixSIAR mixing models with delta13C and delta15N stable isotope tracers. Armases showed a strong preference for consuming partially-decomposed mangrove material from Avicennia germinans and an equally strong preference for Iva frutescens. Armases also displayed predatory behavior under laboratory conditions, confirming omnivory in the presence of mangrove material. Stable isotopes revealed a pattern of elevated trophic position of Armases in disturbed habitats over paired natural locations. Diet reconstruction provided coarse resolution of in-situ feeding and results show high spatial variation: in natural habitats, Armases appears to rely heavily upon upland plant material compared to disturbed habitats where it may consume more animal prey. Combined, these findings support that Armases trophic position and diet may indicate habitat quality in mangrove transitions in the southeastern United States.
|
Maynard, J. A., McKagan, S., Raymundo, L., Johnson, S., Ahmadia, G. N., Johnston, L., et al. (2015). Assessing relative resilience potential of coral reefs to inform management. Biological Conservation, 192, 109–119.
Abstract: Ecological resilience assessments are an important part of resilience-based management (REM) and can help prioritize and target management actions. Use of such assessments has been limited due to a lack of clear guidance on the assessment process. This study builds on the latest scientific advances in REM to provide that guidance from a resilience assessment undertaken in the Commonwealth of the Northern Mariana Islands (CNMI). We assessed spatial variation in ecological resilience potential at 78 forereef sites near the populated islands of the CNMI: Saipan, Tinian/Aguijan, and Rota. The assessments are based on measuring indicators of resilience processes and are combined with information on anthropogenic stress and larval connectivity. We find great spatial variation in relative resilience potential with many high resilience sites near Saipan (5 of 7) and low resilience sites near Rota (7 of 9). Criteria were developed to identify priority sites for six types of management actions (e.g., conservation, land-based sources of pollution reduction, and fishery management and enforcement) and 51 of the 78 sites met at least one of the sets of criteria. The connectivity simulations developed indicate that Tinian and Aguijan are each roughly 10 x the larvae source that Rota is and twice as frequent a destination. These results may explain the lower relative resilience potential of Rota reefs and indicates that actions in Saipan and Tinian/Aguijan will be important to maintaining supply of larvae. The process we describe for undertaking resilience assessments can be tailored for use in coral reef areas globally and applied to other ecosystems.
|
Milligan RJ, Scott EM, Jones DOB, Bett BJ, Jamieson AJ, O'Brien, R., et al. (2020). Evidence for seasonal cycles in deep-sea fish abundances: A great migration in the deep SE Atlantic? J Anim Ecol, 89(7), 1593–1603.
Abstract: Animal migrations are of global ecological significance, providing mechanisms for the transport of nutrients and energy between distant locations. In much of the deep sea (>200 m water depth), the export of nutrients from the surface ocean provides a crucial but seasonally variable energy source to seafloor ecosystems. Seasonal faunal migrations have been hypothesized to occur on the deep seafloor as a result, but have not been documented. Here, we analyse a 7.5-year record of photographic data from the Deep-ocean Environmental Long-term Observatory Systems seafloor observatories to determine whether there was evidence of seasonal (intra-annual) migratory behaviours in a deep-sea fish assemblage on the West African margin and, if so, identify potential cues for the behaviour. Our findings demonstrate a correlation between intra-annual changes in demersal fish abundance at 1,400 m depth and satellite-derived estimates of primary production off the coast of Angola. Highest fish abundances were observed in late November with a smaller peak in June, occurring approximately 4 months after corresponding peaks in primary production. Observed changes in fish abundance occurred too rapidly to be explained by recruitment or mortality, and must therefore have a behavioural driver. Given the recurrent patterns observed, and the established importance of bottom-up trophic structuring in deep-sea ecosystems, we hypothesize that a large fraction of the fish assemblage may conduct seasonal migrations in this region, and propose seasonal variability in surface ocean primary production as a plausible cause. Such trophic control could lead to changes in the abundance of fishes across the seafloor by affecting secondary production of prey species and/or carrion availability for example. In summary, we present the first evidence for seasonally recurring patterns in deep-sea demersal fish abundances over a 7-year period, and demonstrate a previously unobserved level of dynamism in the deep sea, potentially mirroring the great migrations so well characterized in terrestrial systems.
|
Rassweiler, A., Ojea, E., & Costello, C. (2020). Strategically designed marine reserve networks are robust to climate change driven shifts in population connectivity. Environ. Res. Lett., .
Abstract: Marine reserves can be effective conservation and fishery management tools, particularly when their design accounts for spatial population connectivity. Yet climate change is expected to significantly alter larval connectivity of many marine species, questioning whether marine reserves designed today will still be effective in the future. Here we predict how alternative marine reserve designs will affect fishery yields. We apply a range of empirically-grounded scenarios for future larval dispersal to fishery models of seven species currently managed through marine reserves in the nearshore waters in Southern California, USA. We show that networks of reserves optimized for future climate conditions differ substantially from networks designed for today's conditions. However, the benefits of redesign are modest: a set of reserves designed for current conditions commonly produces outcomes within 10% of the best redesigned network, and far outperforms haphazardly designed networks. Thus, investing in the strategic design of marine reserves networks today may pay dividends even if the networks are not modified to keep up with environmental change.
|
Valle-Levinson, A., Kourafalou, V. H., Smith, R. H., & Androulidakis, Y. (2020). Flow structures over mesophotic coral ecosystems in the eastern Gulf of Mexico. Continental Shelf Research, 207(16).
Abstract: Simultaneous time series of current velocity profiles are used to characterize flow structures over intermediate-depth coral ecosystems in the eastern Gulf of Mexico. Understanding of temporal variability and spatial coherence in flow is necessary to establish connectivity among these ecosystems. Time series were collected at Pulley Ridge (the westernmost site), Northern Dry Tortugas, and Southern Dry Tortugas. Overlapping data spanned the period from March 22, 2013 to June 20, 2015. The strongest currents were approximately 1 m s-1 southeastward at Pulley Ridge. Subtidal velocities from the three sites were decomposed into real-vector, concatenated empirical orthogonal functions (EOFs). Results from EOFs indicated that Mode 1, which explained 63% of the subtidal variance, was roughly in the same direction at each of the three sites. Mode 1 directionality indicated potential interconnectivity between Pulley Ridge and Southern Dry Tortugas, and between Northern Dry Tortugas and Pulley Ridge. Mode 1 also suggested limited to no connectivity between the two Dry Tortugas sites as the flows over the two sites were parallel. Mode 2 explained close to 24% of the variance and showed incoherence among the three sites. Wavelet analysis of EOF coefficients indicated dominance of >1 week variability in this region. Flow variability may be associated with wind forcing and Loop Current variability as confirmed by satellite altimetry. Wind forcing caused part of the intra-monthly (<1 month) periodicity in flows. Sea level in the area of the Loop Current, as derived from EOF application on altimetry data during the period of velocity measurements, was related to Mode 1 of the currents at sub-monthly (>1 month) periods. The relationship was more robust, but inverse, when comparing sea level off the northwestern coast of Cuba to the Mode 1 of the currents. These results characterize physical connectivity among South Florida coral ecosystems and have biophysical implications for coral fish populations.
|
Zhu, M. - J., Hoctor, T. S., Volk, M., Frank, K. I., Zwick, P. D., Carr, M. H., et al. (2015). Spatial conservation prioritization to conserve biodiversity in response to sea level rise and land use change in the Matanzas River Basin, Northeast Florida. Landscape and Urban Planning, 144, 103–118.
Abstract: Sea level rise and land use change are likely to be some of the most fundamental and important challenges for biodiversity conservation in low-lying coastal areas in the 21st century. To protect biodiversity in coastal areas, there is an urgent need to identify conservation priorities in response to sea level rise and land use change. In this study, an integrated modeling process using a geomorphological model, species habitat models, and conservation prioritization is developed to identify conservation priorities in the face of sea level rise and land use change. We present a case study in the Matanzas River Basin of Northeast Florida that utilizes this integrated modeling approach with data for 38 focal species. We incorporate species-specific connectivity requirements in the analysis and compare the conservation priorities with existing conservation datasets including current conservation areas and the Florida Ecological Greenways Network (FEGN). Results show that current reserves are not adequate to protect some of the most important conservation priorities in response to sea level rise but the updated FEGN does serve as a good foundation to inform future conservation decisions relevant to sea level rise. To protect the top 10% conservation priorities, approximately 11,700, 10,900 and 15,200 acres of additional land will need to be acquired for the 0.5, 1.0, and 2.5 m sea level rise scenarios respectively.
|
