scholarly journals Baseline Alligator Nesting Data in Arthur R. Marshall Loxahatchee National Wildlife Refuge to Inform Monitoring

2018 ◽  
Vol 10 (1) ◽  
pp. 266-276
Author(s):  
Laura A. Brandt
Keyword(s):  
Baseline Data ◽  
Alligator Mississippiensis ◽  
Spatial And Temporal Variability ◽  
National Wildlife Refuge ◽  
Wildlife Refuge ◽  
Management Actions ◽  
Monitoring Strategies ◽  
Loxahatchee National Wildlife Refuge ◽  
Monitoring Protocols ◽  
Hydrologic Conditions

Abstract Monitoring key ecological attributes helps land managers understand the current state of the resource and decide if management action is necessary. Baseline data on spatial and temporal variability of attributes to be monitored is important for development of successful monitoring programs. In this study, I collected data from 2000 to 2004 on American alligator Alligator mississippiensis nesting in the Arthur R. Marshall Loxahatchee National Wildlife Refuge to determine feasibility of conducting alligator nest surveys and collect baseline data on alligator nesting status and variability. I used nest data to provide examples of potential monitoring strategies for tracking trends over time or understanding the effects of different hydrologic conditions on alligator nesting. Conducting ground surveys with airboats in Arthur R. Marshall Loxahatchee National Wildlife Refuge proved to be an effective method of finding alligator nests. Number of nests per 1.6 km × 1.6 km (256-ha) plot ranged from 1 to 12, and by year from 28 to 53. Overall, average number of nests per hour ranged from 1.8 ± 0.26 (SE) in 2000 to a low of 0.84 ± 0.08 in 2004. Using data from this study for the six plots sampled each year, and assuming no change in variability, power analysis shows that 10 y of sampling would allow for detection of an annual 10% change in number of nests per hour, with power and level of certainty set equal at 90% (β and α both 0.10). Additionally, 15 y of data would allow for a detection of a 5% change per year. Thirty-seven plots per area would be necessary to assess a 40% difference in number of alligator nests per hour in areas with different hydrologic conditions with power and level of certainty at 90%. Land managers can use these data and analyses, along with examples of monitoring strategies, to guide development of more specific monitoring protocols that address restoration objectives and management actions throughout the Florida Everglades.

Reconstructing Vegetation Response to AlteredHydrology and its Use for Restoration, Arthur R. Marshall Loxahatchee National Wildlife Refuge, Florida

Wetlands ◽  
2013 ◽  
Vol 33 (6) ◽  
pp. 1139-1149 ◽  
Author(s):  
Christopher E. Bernhardt ◽  
Laura A. Brandt ◽  
Bryan Landacre ◽  
Marci E. Marot ◽  
Debra A. Willard
Keyword(s):  
Vegetation Response ◽  
National Wildlife Refuge ◽  
Wildlife Refuge ◽  
Loxahatchee National Wildlife Refuge

Hurricane Impacts to Tree Islands in Arthur R. Marshall Loxahatchee National Wildlife Refuge, Florida

2006 ◽  
Vol 5 (4) ◽  
pp. 737-746 ◽  
Author(s):  
Cristina A. Ugarte ◽  
Laura A. Brandt ◽  
Stefani Melvin ◽  
Frank J. Mazzotti ◽  
Kenneth G. Rice
Keyword(s):  
Tree Islands ◽  
National Wildlife Refuge ◽  
Wildlife Refuge ◽  
Hurricane Impacts ◽  
Loxahatchee National Wildlife Refuge

WILDLIFE AND VEGETATION OF BAYHEAD ISLANDS IN THE A.R.M. LOXAHATCHEE NATIONAL WILDLIFE REFUGE

2003 ◽  
Vol 2 (2) ◽  
pp. 179-194 ◽  
Author(s):  
Laura A. Brandt ◽  
Dennis Ecker ◽  
Ivonne Gomez Rivera ◽  
Ashley Traut ◽  
Frank J. Mazzotti
Keyword(s):  
National Wildlife Refuge ◽  
Wildlife Refuge ◽  
Loxahatchee National Wildlife Refuge

scholarly journals High Times and Dry Times In a Salt Marsh: Budgeting For Supplemental Freshwater Needs at the Big Boggy National Wildlife Refuge, USA

2022 ◽  
Author(s):  
Matthew Madewell ◽  
Rusty Feagin ◽  
Thomas Huff ◽  
Bill Balboa
Keyword(s):  
Salt Marsh ◽  
Salt Marshes ◽  
Freshwater Input ◽  
National Wildlife Refuge ◽  
Management Options ◽  
Wildlife Refuge ◽  
Management Actions ◽  
Seasonal Droughts ◽  
Freshwater Inflows ◽  
Vegetation Loss

Abstract Salt marshes can be vulnerable to reduced freshwater input. Reduced freshwater inflows, particularly during a hot or dry summer season, can be catastrophic for vegetation productivity, organic accretion and inorganic sedimentation, and the ability of a marsh to maintain a sustainable elevation facing relative sea level rise (RSLR). Unfortunately, it is challenging for scientists to obtain inflow records for ungauged watersheds and link them with historical trends of salt marsh loss. We sought to address this challenge in Big Boggy National Wildlife Refuge (NWR), a small watershed in East Matagorda Bay, Texas. Our objective was to link the quantity of freshwater inflow with salt marsh sustainability and recommend management actions for the NWR. We first explored land cover trends and found that this watershed lost more than one-third of its low marsh since 1953. We then measured the streamflow into and out of the watershed, created a water budget, and modeled historical and future inflows from 1953 to 2100. Freshwater inflows have been increasing on average since 1953, but a combination of RSLR, sediment starvation, and punctuated seasonal droughts are likely responsible for the loss of salt marsh. We also estimated supplemental water needs during potential droughts out to 2100. We conclude that managers cannot fundamentally alter the accretion versus RSLR balance in this basin except by modifying freshwater input. Thus, during droughts, they should focus on providing these inputs and avoiding vegetation loss. Our work points to both water purchases and land management options that can achieve this goal.

A Markov Decision Process for Managing Habitat for Florida Scrub-Jays

2011 ◽  
Vol 2 (2) ◽  
pp. 234-246 ◽  
Author(s):  
Fred A. Johnson ◽  
David R. Breininger ◽  
Brean W. Duncan ◽  
James D. Nichols ◽  
Michael C. Runge ◽  
...  
Keyword(s):  
Transition Probabilities ◽  
Survival Rates ◽  
Monitoring Program ◽  
Optimal Management ◽  
Prescribed Burn ◽  
National Wildlife Refuge ◽  
Florida Scrub ◽  
Wildlife Refuge ◽  
Management Actions ◽  
Optimal Action

Abstract Florida scrub-jays Aphelocoma coerulescens are listed as threatened under the Endangered Species Act due to loss and degradation of scrub habitat. This study concerned the development of an optimal strategy for the restoration and management of scrub habitat at Merritt Island National Wildlife Refuge, which contains one of the few remaining large populations of scrub-jays in Florida. There are documented differences in the reproductive and survival rates of scrub-jays among discrete classes of scrub height (<120 cm or “short”; 120–170 cm or “optimal”; >170 cm or “tall”; and a combination of tall and optimal or “mixed”), and our objective was to calculate a state-dependent management strategy that would maximize the long-term growth rate of the resident scrub-jay population. We used aerial imagery with multistate Markov models to estimate annual transition probabilities among the four scrub-height classes under three possible management actions: scrub restoration (mechanical cutting followed by burning), a prescribed burn, or no intervention. A strategy prescribing the optimal management action for management units exhibiting different proportions of scrub-height classes was derived using dynamic programming. Scrub restoration was the optimal management action only in units dominated by mixed and tall scrub, and burning tended to be the optimal action for intermediate levels of short scrub. The optimal action was to do nothing when the amount of short scrub was greater than 30%, because short scrub mostly transitions to optimal height scrub (i.e., that state with the highest demographic success of scrub-jays) in the absence of intervention. Monte Carlo simulation of the optimal policy suggested that some form of management would be required every year. We note, however, that estimates of scrub-height transition probabilities were subject to several sources of uncertainty, and so we explored the management implications of alternative sets of transition probabilities. Generally, our analysis demonstrated the difficulty of managing for a species that requires midsuccessional habitat, and suggests that innovative management tools may be needed to help ensure the persistence of scrub-jays at Merritt Island National Wildlife Refuge. The development of a tailored monitoring program as a component of adaptive management could help reduce uncertainty about controlled and uncontrolled variation in transition probabilities of scrub-height and thus lead to improved decision making.

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