Projected Status of the Ghost Orchid (Dendrophylax lindenii) in Florida during the Next Decade Based on Temporal Dynamic Studies Spanning Six Years

The enigmatic ghost orchid, Dendrophylax lindenii (Lindley) Bentham ex Rolfe, is a showy leafless epiphyte restricted to low-lying forests in south Florida and western Cuba. Because of its appeal and reputation for being difficult to cultivate, D. lindenii remains vulnerable to poaching and environmental changes. About 2000 individuals are assumed to remain in Florida, most confined within water-filled cypress domes in the Fakahatchee Strand, but virtually no information exists on current population numbers throughout the region. This paper provides a preliminary summary of the ghost orchid’s projected status based on six continuous years of data collected within the Florida Panther National Wildlife Refuge (FPNWR) from 2015–2020. The orchids were clustered in seven different populations, each separated by ca. 5 km. Quantitative data were collected spanning three age classes (seedlings, juveniles, mature plants) for each population, and survival, flowering, and fruiting were noted. To estimate the temporal variability in the demographic rates, size-structured integral projection models (IPMs) were constructed for each annual transition (e.g., 2015–2016, 2016–2017). Results for all seven populations pooled suggest that D. lindenii numbers will decline by 20% during the next decade in the absence of external adverse factors. Seedling recruitment is not expected to keep pace with the projected decline. Only one population, which was also from the wettest location, continuously harbored spontaneous seedlings, suggesting that most populations within the FPNWR lack conditions suitable for reproduction.

A statistical evaluation of the origin of cypress domes in Florida

Two competing explanations exist for the origin of one type of karstic landform found in Florida called the cypress dome. One explanation relies on complex ecological feedbacks stemming from nutrient cycling suggesting biota contribute more significantly to processes of landscape evolution in Florida than anywhere else in the world. The second explanation is that the landforms are sinkholes that completely preclude the biological explanation while fitting more parsimoniously with the surrounding geological narrative. This work puts forward geostatistical analyses and a model linking the landforms to sinkholes, thus bolstering the geological explanation for origin of the landform. Satellite imagery of sinkholes occurring in limestone from locations spanning the planet was analyzed. Measurements of globally distributed limestone sinkhole surface areas are best characterized by an exponential distribution indicating sinkhole formation is robust to starting conditions (i.e., climate, tectonics). This observation is supported by an analysis of sinkhole geometry and geospatial dispersion. This demonstrates the geospatial parameters space for globally distributed groups of sinkholes forming in limestone are statistically indistinguishable despite sinkhole formation in different climates, tectonic regimes, and at different times. Employing this observation as a tool, sinkholes are directly compared to the cypress domes in Florida and are found to be statistically indistinguishable. From the striking similarity in spatial parameter spaces in conjunction with the geologic history of the area, it is interpreted that these landforms originate through geologic, not biologic, processes.

A statistical evaluation of the origin of cypress domes in Florida

© 2020 Elsevier B.V. Two competing explanations exist for the origin of one type of karstic landform found in Florida called the cypress dome. One explanation relies on complex ecological feedbacks stemming from nutrient cycling suggesting biota contribute more significantly to processes of landscape evolution in Florida than anywhere else in the world. The second explanation is that the landforms are sinkholes that completely preclude the biological explanation while fitting more parsimoniously with the surrounding geological narrative. This work puts forward geostatistical analyses and a model linking the landforms to sinkholes, thus bolstering the geological explanation for origin of the landform. Satellite imagery of sinkholes occurring in limestone from locations spanning the planet was analyzed. Measurements of globally distributed limestone sinkhole surface areas are best characterized by an exponential distribution indicating sinkhole formation is robust to starting conditions (i.e., climate, tectonics). This observation is supported by an analysis of sinkhole geometry and geospatial dispersion. This demonstrates the geospatial parameters space for globally distributed groups of sinkholes forming in limestone are statistically indistinguishable despite sinkhole formation in different climates, tectonic regimes, and at different times. Employing this observation as a tool, sinkholes are directly compared to the cypress domes in Florida and are found to be statistically indistinguishable. From the striking similarity in spatial parameter spaces in conjunction with the geologic history of the area, it is interpreted that these landforms originate through geologic, not biologic, processes.

A statistical evaluation of the origin of cypress domes in Florida

Two competing explanations exist for the origin of one type of karstic landform found in Florida called the cypress dome. One explanation relies on complex ecological feedbacks stemming from nutrient cycling suggesting biota contribute more significantly to processes of landscape evolution in Florida than anywhere else in the world. The second explanation is that the landforms are sinkholes that completely preclude the biological explanation while fitting more parsimoniously with the surrounding geological narrative. This work puts forward geostatistical analyses and a model linking the landforms to sinkholes, thus bolstering the geological explanation for origin of the landform. Satellite imagery of sinkholes occurring in limestone from locations spanning the planet was analyzed. Measurements of globally distributed limestone sinkhole surface areas are best characterized by an exponential distribution indicating sinkhole formation is robust to starting conditions (i.e., climate, tectonics). This observation is supported by an analysis of sinkhole geometry and geospatial dispersion. This demonstrates the geospatial parameters space for globally distributed groups of sinkholes forming in limestone are statistically indistinguishable despite sinkhole formation in different climates, tectonic regimes, and at different times. Employing this observation as a tool, sinkholes are directly compared to the cypress domes in Florida and are found to be statistically indistinguishable. From the striking similarity in spatial parameter spaces in conjunction with the geologic history of the area, it is interpreted that these landforms originate through geologic, not biologic, processes.

A statistical evaluation of the origin of cypress domes in Florida

© 2020 Elsevier B.V. Two competing explanations exist for the origin of one type of karstic landform found in Florida called the cypress dome. One explanation relies on complex ecological feedbacks stemming from nutrient cycling suggesting biota contribute more significantly to processes of landscape evolution in Florida than anywhere else in the world. The second explanation is that the landforms are sinkholes that completely preclude the biological explanation while fitting more parsimoniously with the surrounding geological narrative. This work puts forward geostatistical analyses and a model linking the landforms to sinkholes, thus bolstering the geological explanation for origin of the landform. Satellite imagery of sinkholes occurring in limestone from locations spanning the planet was analyzed. Measurements of globally distributed limestone sinkhole surface areas are best characterized by an exponential distribution indicating sinkhole formation is robust to starting conditions (i.e., climate, tectonics). This observation is supported by an analysis of sinkhole geometry and geospatial dispersion. This demonstrates the geospatial parameters space for globally distributed groups of sinkholes forming in limestone are statistically indistinguishable despite sinkhole formation in different climates, tectonic regimes, and at different times. Employing this observation as a tool, sinkholes are directly compared to the cypress domes in Florida and are found to be statistically indistinguishable. From the striking similarity in spatial parameter spaces in conjunction with the geologic history of the area, it is interpreted that these landforms originate through geologic, not biologic, processes.

Big Cypress fox squirrel ( Sciurus niger avicennia ) ecology and habitat use in a cypress dome swamp-pine forest mosaic

Forested wetlands are in decline, as are many species that are obligate residents. Big Cypress fox squirrels (BCFS; Sciurus niger avicennia ) are a threatened endemic to wet pine and cypress forests in southwestern Florida. The region is characterized by development resulting in habitat loss, habitat fragmentation, and hydrological change that influence the quality of these wet forests. Through radiotelemetry and field observations, we examined the ecology and habitat use of BCFS in a natural cypress dome-pine forest mosaic. BCFS selected cypress domes for food and nests throughout the year. Cypress dome habitats were the only habitat type to be used more than available; however, the availability of nearby pine forest was also important. Home ranges were large relative to other tree squirrels, with male home ranges exceeding female ranges. Males overlapped more females than males, while sharing similar food preferences and use patterns with females, suggesting that the sexual dimorphism in home range size is related to mate searching. Roads and oil extraction pads were used less frequently than expected and were incorporated into home ranges less than randomly generated features. The importance of cypress domes within the wet forests and grasslands of Big Cypress National Preserve demonstrates the value of maintaining this delicate mosaic.