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Krushelnycky PD, Berio Fortini L, Mallinson J, Felts JM. Empirical estimation of habitat suitability for rare plant restoration in an era of ongoing climatic shifts. Sci Rep 2023; 13:19257. [PMID: 37935959 PMCID: PMC10630363 DOI: 10.1038/s41598-023-46793-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/02/2023] [Accepted: 11/05/2023] [Indexed: 11/09/2023] Open
Abstract
Accurate estimates of current and future habitat suitability are needed for species that may require assistance in tracking a shifting climate. Standard species distribution models (SDMs) based on occurrence data are the most common approach for evaluating climatic suitability, but these may suffer from inaccuracies stemming from disequilibrium dynamics and/or an inability to identify suitable climate regions that have no analogues within the current range. An alternative approach is to test performance with experimental introductions, and model suitability from the empirical results. We used this method with the Haleakalā silversword (Argyroxiphium sandwicense subsp. macrocephalum), using a network of out-plant plots across the top of Haleakalā volcano, Hawai'i. Over a ~ 5-year period, survival varied strongly across this network and was effectively explained by a simple model including mean rainfall and air temperature. We then applied this model to estimate current climatic suitability for restoration or translocation activities, to define trends in suitability over the past three decades, and to project future suitability through 2051. This empirical approach indicated that much of the current range has low suitability for long-term successful restoration, but also identified areas of high climatic suitability in a region where plants do not currently occur. These patterns contrast strongly with projections obtained with a standard SDM, which predicted continued suitability throughout the current range. Under continued climatic shifts, these results caution against the common SDM presumption of equilibrium between species' distributions and their environment, even for long-established native species.
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Affiliation(s)
- Paul D Krushelnycky
- Department of Plant and Environmental Protection Sciences, University of Hawai'i at Mānoa, Honolulu, HI, USA.
| | - Lucas Berio Fortini
- U.S. Geological Survey, Pacific Island Ecosystems Research Center, Honolulu, HI, USA
| | - Jeffrey Mallinson
- Resources Management Division, Haleakalā National Park, Makawao, HI, USA
| | - Jesse M Felts
- Resources Management Division, Haleakalā National Park, Makawao, HI, USA
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Berio Fortini L, Krushelnycky PD, Drake DR, Starr F, Starr K, Chimera CG. Complex demographic responses to contrasting climate drivers lead to divergent population trends across the range of a threatened alpine plant. Glob Ecol Conserv 2022. [DOI: 10.1016/j.gecco.2021.e01954] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/01/2022] Open
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Krushelnycky PD, Felts JM, Robichaux RH, Barton KE, Litton CM, Brown MD. Clinal variation in drought resistance shapes past population declines and future management of a threatened plant. ECOL MONOGR 2020. [DOI: 10.1002/ecm.1398] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Affiliation(s)
- Paul D. Krushelnycky
- Department of Plant and Environmental Protection Sciences University of Hawaiʻi at Mānoa Honolulu Hawaiʻi 96822 USA
| | - Jesse M. Felts
- Resources Management Division Haleakalā National Park Makawao Hawaiʻi 96768 USA
| | - Robert H. Robichaux
- Department of Ecology and Evolutionary Biology University of Arizona Tucson Arizona 85721 USA
| | - Kasey E. Barton
- Department of Botany University of Hawaiʻi at Mānoa Honolulu Hawaiʻi 96822 USA
| | - Creighton M. Litton
- Department of Natural Resources and Environmental Management University of Hawaiʻi at Mānoa Honolulu Hawaiʻi 96822 USA
| | - Matthew D. Brown
- Resources Management Division Haleakalā National Park Makawao Hawaiʻi 96768 USA
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Tong RL, Grace JK, Krushelnycky PD, Spafford H. Roadside Survey of Ants on Oahu, Hawaii. Insects 2018; 9:insects9010021. [PMID: 29439503 PMCID: PMC5872286 DOI: 10.3390/insects9010021] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 09/12/2017] [Revised: 01/29/2018] [Accepted: 02/06/2018] [Indexed: 06/08/2023]
Abstract
Hawaii is home to over 60 ant species, including five of the six most damaging invasive ants. Although there have been many surveys of ants in Hawaii, the last island-wide hand-collection survey of ants on Oahu was conducted in 1988-1994. In 2012, a timed hand-collection of ants was made at 44 sites in a systematic, roadside survey throughout Oahu. Ants were identified and species distribution in relation to elevation, precipitation and soil type was analyzed. To assess possible convenience sampling bias, 15 additional sites were sampled further from roads to compare with the samples near roads. Twenty-four species of ants were found and mapped; Pheidole megacephala (F.), Ochetellus glaber (Mayr), and Technomyrmex difficilis Forel were the most frequently encountered ants. For six ant species, a logistic regression was performed with elevation, average annual precipitation, and soil order as explanatory variables. O. glaber was found in areas with lower precipitation around Oahu. Paratrechina longicornis (Latrielle) and Tetramorium simillimum (Smith, F.) were found more often in lower elevations and in areas with the Mollisol soil order. Elevation, precipitation, and soil type were not significant sources of variation for P. megacephala, Plagiolepis alluaudi Emery, and T. difficilis. P. megacephala was associated with fewer mean numbers of ants where it occurred. Ant assemblages near and far from roads did not significantly differ. Many species of ants remain established on Oahu, and recent invaders are spreading throughout the island. Mapping ant distributions contributes to continued documentation and understanding of these pests.
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Affiliation(s)
- Reina L Tong
- College of Tropical Agriculture and Human Resources, University of Hawaii at Mānoa, 3050 Maile Way, Gilmore Hall 310, Honolulu, HI 96822, USA.
| | - J Kenneth Grace
- College of Tropical Agriculture and Human Resources, University of Hawaii at Mānoa, 3050 Maile Way, Gilmore Hall 310, Honolulu, HI 96822, USA.
| | - Paul D Krushelnycky
- College of Tropical Agriculture and Human Resources, University of Hawaii at Mānoa, 3050 Maile Way, Gilmore Hall 310, Honolulu, HI 96822, USA.
| | - Helen Spafford
- College of Tropical Agriculture and Human Resources, University of Hawaii at Mānoa, 3050 Maile Way, Gilmore Hall 310, Honolulu, HI 96822, USA.
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Krushelnycky PD. Evaluating the interacting influences of pollination, seed predation, invasive species and isolation on reproductive success in a threatened alpine plant. PLoS One 2014; 9:e88948. [PMID: 24551195 PMCID: PMC3925224 DOI: 10.1371/journal.pone.0088948] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/17/2013] [Accepted: 01/17/2014] [Indexed: 11/18/2022] Open
Abstract
Reproduction in rare plants may be influenced and limited by a complex combination of factors. External threats such as invasive species and landscape characteristics such as isolation may impinge on both pollination and seed predation dynamics, which in turn can strongly affect reproduction. I assessed how patterns in floral visitation, seed predation, invasive ant presence, and plant isolation influenced one another and ultimately affected viable seed production in Haleakalā silverswords (Argyroxiphium sandwicense subsp. macrocephalum) of Hawai'i. Floral visitation was dominated by endemic Hylaeus bees, and patterns of visitation were influenced by floral display size and number of plants clustered together, but not by floral herbivory or nearest flowering neighbor distance. There was also some indication that Argentine ant presence impacted floral visitation, but contradictory evidence and limitations of the study design make this result uncertain. Degree of seed predation was associated only with plant isolation, with the two main herbivores partitioning resources such that one preferentially attacked isolated plants while the other attacked clumped plants; total seed predation was greater in more isolated plants. Net viable seed production was highly variable among individuals (0-55% seed set), and was affected mainly by nearest neighbor distance, apparently owing to low cross-pollination among plants separated by even short distances (>10-20 m). This isolation effect dominated net seed set, with no apparent influence from floral visitation rates, percent seed predation, or invasive ant presence. The measured steep decline in seed set with isolation distance may not be typical of the entire silversword range, and may indicate that pollinators in addition to Hylaeus bees could be important for greater gene flow. Management aimed at maintaining or maximizing silversword reproduction should focus on the spatial context of field populations and outplanting efforts, as well as on conserving the widest possible range of pollinator taxa.
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Affiliation(s)
- Paul D. Krushelnycky
- Department of Plant and Environmental Protection Sciences, University of Hawai’i at Mānoa, Honolulu, Hawai’i, United States of America
- * E-mail:
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Krushelnycky PD, Loope LL, Giambelluca TW, Starr F, Starr K, Drake DR, Taylor AD, Robichaux RH. Climate-associated population declines reverse recovery and threaten future of an iconic high-elevation plant. Glob Chang Biol 2013; 19:911-922. [PMID: 23504847 DOI: 10.1111/gcb.12111] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/10/2012] [Accepted: 10/29/2012] [Indexed: 06/01/2023]
Abstract
Although climate change is predicted to place mountain-top and other narrowly endemic species at severe risk of extinction, the ecological processes involved in such extinctions are still poorly resolved. In addition, much of this biodiversity loss will likely go unobserved, and therefore largely unappreciated. The Haleakalā silversword is restricted to a single volcano summit in Hawai'i, but is a highly charismatic giant rosette plant that is viewed by 1-2 million visitors annually. We link detailed local climate data to a lengthy demographic record, and combine both with a population-wide assessment of recent plant mortality and recruitment, to show that after decades of strong recovery following successful management, this iconic species has entered a period of substantial climate-associated decline. Mortality has been highest at the lower end of the distributional range, where most silverswords occur, and the strong association of annual population growth rates with patterns of precipitation suggests an increasing frequency of lethal water stress. Local climate data confirm trends toward warmer and drier conditions on the mountain, and signify a bleak outlook for silverswords if these trends continue. The silversword example foreshadows trouble for diversity in other biological hotspots, and illustrates how even well-protected and relatively abundant species may succumb to climate-induced stresses.
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Affiliation(s)
- Paul D Krushelnycky
- Department of Plant and Environmental Protection Sciences, University of Hawai'i at Mānoa, Honolulu, HI 96822, USA.
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Shiels AB, Flores CA, Khamsing A, Krushelnycky PD, Mosher SM, Drake DR. Dietary niche differentiation among three species of invasive rodents (Rattus rattus, R. exulans, Mus musculus). Biol Invasions 2012. [DOI: 10.1007/s10530-012-0348-0] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
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Krushelnycky PD, Gillespie RG. Sampling across space and time to validate natural experiments: an example with ant invasions in Hawaii. Biol Invasions 2009. [DOI: 10.1007/s10530-009-9471-y] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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Abstract
There is a general consensus that the diversity of a biotic community can have an influence on its stability, but the strength, ubiquity, and relative importance of this effect is less clear. In the context of biological invasions, diversity has usually been studied in terms of its effect on a community's invasibility, but diversity may also influence stability by affecting the magnitude of compositional or functional changes experienced by a community upon invasion. We examined the impacts of invasive ants on arthropod communities at five natural area sites in the Hawaiian Islands, and assessed whether differences among sites in community diversity and density variables were related to measures of stability. Ant invasion was usually associated with significant changes in overall community composition, as measured by Bray-Curtis distances, particularly among endemic subsets of the communities. Changes in mean species richness were also strong at three of the five sites. Among sites, diversity was negatively related to stability as measured by resistance to overall compositional change, but this effect could not be separated from the strong negative effect of invasive ant density on compositional stability. When compositional stability was measured as proportional change in richness, the best predictor of stability among endemic community subsets was endemic richness, with richer communities losing proportionately more species than species-poor communities. This effect was highly significant even after controlling for differences in invasive ant density and suggested that communities that had already lost many endemic species were resistant to further species loss upon ant invasion, while more intact communities remained vulnerable to species loss. Communities underwent strong but idiosyncratic functional shifts in association with ant invasion, both in terms of trophic structure and total arthropod biomass. There were no apparent relationships, however, between functional stability and community diversity or density measures. Instead, invasive ant density was the best among-site predictor of the magnitude of functional change. Overall, diversity appeared to be a poor predictor of stability in the face of ant invasion in these communities, possibly because any actual diversity effects were overshadowed by community-specific factors and variation in the magnitude of the ant-mediated perturbation.
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Affiliation(s)
- Paul D Krushelnycky
- Department of Environmental Science, Policy and Management, 137 Mulford Hall, University of California, Berkeley, California 94720-3114, USA.
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Krushelnycky PD, Joe SM, Medeiros AC, Daehler CC, Loope LL. The role of abiotic conditions in shaping the long-term patterns of a high-elevation Argentine ant invasion. DIVERS DISTRIB 2005. [DOI: 10.1111/j.1366-9516.2005.00151.x] [Citation(s) in RCA: 45] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022] Open
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Krushelnycky PD, Loope LL, Joe SM. Limiting Spread of a Unicolonial Invasive Insect and Characterization of Seasonal Patterns of Range Expansion. Biol Invasions 2004. [DOI: 10.1023/b:binv.0000010121.45225.cc] [Citation(s) in RCA: 32] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
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