No effect of seed source on multiple aspects of ecosystem functioning during ecological restoration: cultivars compared to local ecotypes of dominant grasses

Genetic principles underlie recommendations to use local seed, but a paucity of information exists on the genetic distinction and ecological consequences of using different seed sources in restorations. We established a field experiment to test whether cultivars and local ecotypes of dominant prairie grasses were genetically distinct and differentially influenced ecosystem functioning. Whole plots were assigned to cultivar and local ecotype grass sources. Three subplots within each whole plot were seeded to unique pools of subordinate species. The cultivar of the increasingly dominant grass, Sorghastrum nutans, was genetically different than the local ecotype, but genetic diversity was similar between the two sources. There were no differences in aboveground net primary production, soil carbon accrual, and net nitrogen mineralization rate in soil between the grass sources. Comparable productivity of the grass sources among the species pools for four years shows functional equivalence in terms of biomass production. Subordinate species comprised over half the aboveground productivity, which may have diluted the potential for documented trait differences between the grass sources to influence ecosystem processes. Regionally developed cultivars may be a suitable alternative to local ecotypes for restoration in fragmented landscapes with limited gene flow between natural and restored prairie and negligible recruitment by seed

Threatened and Endangered Subspecies with Vulnerable Ecological Traits Also Have High Susceptibility to Sea Level Rise and Habitat Fragmentation

The presence of multiple interacting threats to biodiversity and the increasing rate of species extinction make it critical to prioritize management efforts on species and communities that maximize conservation success. We implemented a multi-step approach that coupled vulnerability assessments evaluating threats to Florida taxa such as climate change, sea-level rise, and habitat fragmentation with in-depth literature surveys of taxon-specific ecological traits. The vulnerability, adaptive capacity, and ecological traits of 12 threatened and endangered subspecies were compared to non-listed subspecies of the same parent species. Overall, the threatened and endangered subspecies showed high vulnerability and low adaptive capacity, in particular to sea level rise and habitat fragmentation. They also exhibited larger home ranges and greater dispersal limitation compared to non-endangered subspecies, which may inhibit their ability to track changing climate in fragmented landscapes. There was evidence for lower reproductive capacity in some of the threatened or endangered taxa, but not for most. Taxa located in the Florida Keys or in other low coastal areas were most vulnerable to sea level rise, and also showed low levels of adaptive capacity, indicating they may have a lower probability of conservation success. Our analysis of at-risk subspecies and closely related non-endangered subspecies demonstrates that ecological traits help to explain observed differences in vulnerability and adaptive capacity. This study points to the importance of assessing the relative contributions of multiple threats and evaluating conservation value at the species (or subspecies) level when resources are limited and several factors affect conservation success

Satellite Tracking Reveals Use of Biscayne National Park by Sea Turtles Tagged in Multiple Locations

Although historical observations date back to the 1800’s, there is little information on sea turtle occupancy within Biscayne National Park (BNP). The park is located along the Florida reef tract and is dominated by the Gulfstream, which acts as a corridor for many marine animals. Here we used satellite telemetry to determine areas of use in BNP for two species of imperiled sea turtles, loggerhead (Caretta caretta) and green (Chelonia mydas) turtles. We included data for turtles tagged between 2009–2021 at sites both within park waters and in five locations outside the park boundary; individuals were captured both in the water and on land. We tagged 60 individuals (female, n=48; male, n=3; immature, n=9); loggerheads (n=33) ranged in size from 66.2 cm to 109.9 cm CCL (curved carapace length) and green turtles (n=27) ranged in size from 39.1 to 111.9 cm CCL. We used behavior switching state-space modeling (SSM) to obtain daily predicted positions for each turtle, classified turtle behavior within the park as either foraging, migration, or both foraging and migration, and summarized high use areas for each species across all months of the year. Turtles used park waters year-round, with concentrated use of deeper waters during seasonal migrations. Across all 60 turtles, 21 spent their tracking time foraging within BNP boundaries and 30 used the park as part of their migratory pathway; five turtles used the park for both foraging and migration, and the remaining four had SSM points very close to the park. Loggerhead migration occurred from February through November, whereas green turtle migration was concentrated in August. Both turtle species exhibited high overlap (i.e., usage) with seagrass habitat. These findings are relevant as managers consider strategies to minimize anthropogenic impacts to resident and migratory sea turtles using park waters

Data from: No effect of seed source on multiple aspects of ecosystem functioning during ecological restoration: cultivars compared to local ecotypes of dominant grasses

Genetic principles underlie recommendations to use local seed, but a paucity of information exists on the genetic distinction and ecological consequences of using different seed sources in restorations. We established a field experiment to test whether cultivars and local ecotypes of dominant prairie grasses were genetically distinct and differentially influenced ecosystem functioning. Whole plots were assigned to cultivar and local ecotype grass sources. Three subplots within each whole plot were seeded to unique pools of subordinate species. The cultivar of the increasingly dominant grass, Sorghastrum nutans, was genetically different than the local ecotype, but genetic diversity was similar between the two sources. There were no differences in aboveground net primary production, soil carbon accrual, and net nitrogen mineralization rate in soil between the grass sources. Comparable productivity of the grass sources among the species pools for four years shows functional equivalence in terms of biomass production. Subordinate species comprised over half the aboveground productivity, which may have diluted the potential for documented trait differences between the grass sources to influence ecosystem processes. Regionally developed cultivars may be a suitable alternative to local ecotypes for restoration in fragmented landscapes with limited gene flow between natural and restored prairie and negligible recruitment by seed

Reproduction within taxon-pairs.

<p>Mean litter or clutch size (± SE) for taxon-pairs with a minimum of three independent observations per taxon. For each taxon-pair, bars with different letters are significantly different (shaded bars = threatened and endangered subspecies; white bars = non-listed subspecies; p<0.05). Taxon-pairs are labeled according to the federally listed subspecies: <i>Pcc</i> = <i>Puma concolor coryi</i>, <i>Ppp</i> = <i>Peromyscus polionotus phasma</i>, <i>Asf</i> = <i>Ammodramus savannarum floridanus</i>, <i>Amm</i> = <i>Ammodramus maritimus mirabilis</i>, <i>Ppa</i> = <i>Polyborus plancus audubonii</i>, <i>Rsp</i> = <i>Rostrhamus sociabilis plumbeus</i>.</p

Ecological trait values.

<p>Mean ecological trait values (± SE) in threatened and endangered subspecies (shaded bars) and non-listed subspecies (white bars) for litter or clutch size, home range size, dispersal distance, and annual adult survival. Data were transformed to proportions of the maximum value for each taxon-pair x trait combination. For each trait, bars with different letters are significantly different (p<0.05).</p

Study species.

<p>Study species comprised 12 taxon-pairs, each included a federally threatened or endangered subspecies and a closely related non-listed subspecies in the same parent species group (in some cases, two non-listed subspecies were used for comparison). Scientific nomenclature for listed subspecies followed the U.S. Fish and Wildlife Service Endangered Species Program <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0070647#pone.0070647-US1" target="_blank">[11]</a>; nomenclature for non-listed subspecies followed the Integrated Taxonomic Information System <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0070647#pone.0070647-IntegratedTaxonomicInformation1" target="_blank">[27]</a> and supplemental literature when indicated.</p>a<p>The endangered taxon <i>Oryzomys palustris natator</i><a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0070647#pone.0070647-US1" target="_blank">[11]</a> is also referred to as <i>Oryzomys argentatus</i><a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0070647#pone.0070647-Indorf1" target="_blank">[66]</a>.</p>b<p>Subspecies taxonomy for <i>O. palustris</i> has undergone several revisions. For this study, we compared the federally endangered population (<i>O</i>. <i>p. natator</i> aka <i>O. argentatus</i>) to two mainland subspecies of <i>O. palustris</i> located in Florida and the southeastern United States. According to <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0070647#pone.0070647-Indorf1" target="_blank">[66]</a>, <i>O. p. natator</i> is a subspecies that occurs in central Florida; it does not interact with the endangered population.</p>c<p>Subspecies taxonomy for <i>Puma concolor</i> has undergone several revisions. According to <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0070647#pone.0070647-Hothorn1" target="_blank">[46]</a>, <i>P</i>. <i>c</i>. <i>couguar</i> refers to cougars throughout North America.</p>d<p><i>Polyborus plancus audubonii</i><a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0070647#pone.0070647-US1" target="_blank">[11]</a> is included as a sub-population of the species <i>Caracara cheriway</i> (northern crested caracara) according to ITIS <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0070647#pone.0070647-IntegratedTaxonomicInformation1" target="_blank">[27]</a> nomenclature. We compared the <i>P</i>. <i>p</i>. <i>audubonii</i> population to other non-interacting individuals with the most geographic similarity in the <i>C. cheriway</i> complex.</p

Threatened and endangered subspecies vulnerability.

<p>Vulnerability of 12 federally threatened and endangered subspecies to sea level rise, habitat fragmentation, altered temperature, and altered precipitation. Sea level rise vulnerability was derived from the percent of habitat inundated under 1 m of sea level rise (Low = 0–25%, Moderate = 26–50%, High = 51–75%, Very high = 76–100%). Vulnerability to habitat fragmentation, altered temperature, and altered precipitation were based on the Standardized Index for Vulnerability and Value Assessment (SIVVA) criteria scores (Neutral = 3, Low = 3–3.75, Moderate = 3.75–4.5, High = 4.5–5.25, Very high = 5.25–6).</p>a<p><i>P. p. audubonii</i> was evaluated to respond positively to altered temperature.</p

Associations between geographic distance to the coast and vulnerability.

<p>Correlation between geographic distance to the coast (natural log) and (<b>A</b>) the vulnerability module of the Standardized Index for Vulnerability and Value Assessment (SIVVA) (r = −0.842, p<0.001), (<b>B</b>) the proportion of habitat inundated under 1 m of sea level rise (r = −0.675, p<0.001), and (<b>C</b>) vulnerability to habitat fragmentation (r = −0.672, p<0.001). Black circles = threatened and endangered subspecies; white squares = non-listed subspecies.</p