Goettsch B.,International Union for Conservation of Nature |
Hilton-Taylor C.,International Union for Conservation of Nature |
Cruz-Pinon G.,Autonomous University of Baja California Sur |
Duffy J.P.,University of Exeter |
And 80 more authors.
Nature Plants | Year: 2015
A high proportion of plant species is predicted to be threatened with extinction in the near future. However, the threat status of only a small number has been evaluated compared with key animal groups, rendering the magnitude and nature of the risks plants face unclear. Here we report the results of a global species assessment for the largest plant taxon evaluated to date under the International Union for Conservation of Nature (IUCN) Red List Categories and Criteria, the iconic Cactaceae (cacti). We show that cacti are among the most threatened taxonomic groups assessed to date, with 31% of the 1,478 evaluated species threatened, demonstrating the high anthropogenic pressures on biodiversity in arid lands. The distribution of threatened species and the predominant threatening processes and drivers are different to those described for other taxa. The most significant threat processes comprise land conversion to agriculture and aquaculture, collection as biological resources, and residential and commercial development. The dominant drivers of extinction risk are the unscrupulous collection of live plants and seeds for horticultural trade and private ornamental collections, smallholder livestock ranching and smallholder annual agriculture. Our findings demonstrate that global species assessments are readily achievable for major groups of plants with relatively moderate resources, and highlight different conservation priorities and actions to those derived from species assessments of key animal groups. © 2015, Nature Publishing Group. All rights reserved.
Troxler T.G.,Florida International University |
Ikenaga M.,Ritsumeikan University |
Scinto L.,Florida International University |
Boyer J.N.,Florida International University |
And 4 more authors.
Wetlands | Year: 2012
Natural environmental gradients provide important information about the ecological constraints on plant and microbial community structure. In a tropical peatland of Panama, we investigated community structure (forest canopy and soil bacteria) and microbial community function (soil enzyme activities and respiration) along an ecosystem development gradient that coincided with a natural P gradient. Highly structured plant and bacterial communities that correlated with gradients in phosphorus status and soil organic matter content characterized the peatland. A secondary gradient in soil porewater NH4 described significant variance in soil microbial respiration and β-1-4-glucosidase activity. Covariation of canopy and soil bacteria taxa contributed to a better understanding of ecological classifications for biotic communities with applicability for tropical peatland ecosystems of Central America. Moreover, plants and soils, linked primarily through increasing P deficiency, influenced strong patterning of plant and bacterial community structure related to the development of this tropical peatland ecosystem. © Society of Wetland Scientists 2012.
Wilder G.J.,Naples Botanical Garden |
Barry M.J.,Institute for Regional Conservation
Journal of the Botanical Research Institute of Texas | Year: 2012
Dismal Key and Fakahatchee Island are islands and shell mounds situated within the Ten Thousand Islands region in the Gulf of Mexico. Each island has three main kinds of habitats: coastal hardwood hammock, insolated terrain, and mangrove. The islands exhibit 63 families, 138 genera, and 172 species of vascular plants, collectively. One hundred and twenty-seven species are native to Florida. Sixteen species are listed as endangered or threatened within Florida. Celtis iguanaea, present on Dismal Key, might exist at solely three other locations in Florida.
Wunderlin R.P.,Institute for Systematic Botany |
Hansen B.F.,Institute for Systematic Botany |
Franck A.R.,Institute for Systematic Botany |
Bradley K.A.,Institute for Regional Conservation |
Kunzer J.M.,Tomoka State Park
Journal of the Botanical Research Institute of Texas | Year: 2010
Thirty four taxa are reported as new to Florida, of which 26 are here reported for the first time as occurring in thecontinental United States Of the total, 33 are non-native to Florida. Of these 33, 25 are ornamentals escaped from cultivation, several of which have the potential to become invasive.
Goodman J.,Fairchild Tropical Botanic Garden |
Walters D.,Fairchild Tropical Botanic Garden |
Bradley K.,Institute for Regional Conservation |
Maschinski J.,Fairchild Tropical Botanic Garden |
Salazar A.,Fairchild Tropical Botanic Garden
Haseltonia | Year: 2012
Understanding soil seed-bank dynamics of endangered species is crucial for their effective management and conservation. Whether or not seeds of Harrisia fragrans Small, a U.S. endangered cactus endemic to Florida (USA) form persistent soil seed-banks or withstand drying and/or freezing under storage conditions was unknown. We conducted a seed burial experiment with seeds collected from three sites (North, Middle, and South) within the Savannas Preserve State Park, FL, USA. We buried the seeds in plots with three light conditions (sun, partial sun, and shade) at each of the three sites and tested their viability in germination trials after 3.5, 8, 11, 16, 19 and 23 months of burial in soil. Buried seeds remained alive throughout the 23 months of the study period with germination ranging from 64 to 100%, which suggests that this species forms a persistent soil seed-bank. Microhabitat conditions markedly affected seed-bank size and subsequent seed viability. Seeds from the South site exhibited higher and faster germination than seeds from the Middle or North sites. We also evaluated if H. fragrans seeds could withstand dry storage under low relative humidity (RH) and low temperature. In the laboratory 76% of seeds stored under 12% RH and -20°C for 1 and 24 weeks germinated faster than seeds stored under 21-23°C and 50% RH. Thus, the capacity of Harrisia fragrans to form a persistent soil seed bank influences population persistence. Its ability to be stored in orthodox ex-situ conditions offers viable options for its future conservation and regeneration. Copyright © 2013 BioOne.
Sah J.P.,Florida International University |
Ross M.S.,Florida International University |
Saha S.,Institute for Regional Conservation |
Minchin P.,Southern Illinois University at Edwardsville |
Sadle J.,Everglades National Park
Wetlands | Year: 2014
Ecosystem management practices that modify the major drivers and stressors of an ecosystem often lead to changes in plant community composition. This paper examines how closely the trajectory of vegetation change in seasonally-flooded wetlands tracks management-induced alterations in hydrology and soil characteristics. We used trajectory analysis, a multivariate method designed to test hypotheses about rates and directions of community change, to examine vegetation shifts in response to changes in water management practices within the Taylor Slough basin of Everglades National Park. We summarized vegetation data by non-metric multidimensional scaling ordination, and examined the time trajectory of each site along environmental vectors representing hydrology and soil phosphorus gradients. In the Taylor Slough basin, vegetation change trajectories closely followed the hydrologic changes caused by the operation of water pumps and detention ponds adjacent to the canals. We also observed a shift in vegetation composition along a vector of increasing soil phosphorus, which suggests the need for implementing measures to avoid Penrichment in southern Everglades marl prairies. This study indicates that shifts in vegetation composition in response to changes in hydrologic conditions and associated parameters may be detected through trajectory analysis, thereby providing feedback for adaptive management of wetland ecosystems. © Society of Wetland Scientists 2013.