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Interactions between species in an anthropogenically altered ridge-top wetland ecosystem Contact Information: Eastern Kentucky University Department of Biological sciences 521 Lancaster Ave. Richmond, KY 40475 Chelsea S. Kross and Stephen C. Richter METHODS RESULTS I used 12 wetlands, 6 constructed and 6 naturals, that were located in the Cumberland District of the Daniel Boone National Forest (DBNF; Figure 1). Wood frog eggs were observed at three constructed wetlands and six natural wetlands (Table 1) and laid in February and March 2013. Wood Frog eggs experienced mortality from abiotic factors (e.g. freezing, drying) and predation (Table 1). Wood Frog Sampling: • Egg mass surveys (January–April 2013; Figure 2A). • Mesh minnow traps for presence or absence of wood frog larva (May 2013; Figure 2B) . Figure 1. Wetlands across the Daniel Boone National Forest. Not all constructed wetlands are shown. The outbox shows the location and distribution of wetlands used in this study. ABSTRACT No wood frog larvae were caught in traps from constructed wetlands (Table 1). Newts were observed eating wood frog eggs and on average ate 37% of wood frog egg masses (Table 1). B. • Mesh minnow traps were used to capture newts in May, July, September, November of 2013 and January–March 2014 (Figure 2B). • Dipnetting was used to capture newts (Sampling was considered completed when no newts were caught after 20 consecutive dips). • SVL, Mass, and Sex were measured • Each individual was marked with a unique code using Visual Implant Elastomer (VIE) for mark-recapture. INTRODUCTION Over 400 wetlands have been constructed on ridge tops within the Daniel Boone National Forest (DBNF) in Kentucky. A. Newt Sampling: Hundreds of wetlands have been constructed as permanent water sources in a ridgetop ecosystem in eastern Kentucky where there were naturally only ephemeral wetlands. Consequently, the ecosystem was colonized by an amphibian community of species with a larval period that requires a long hydroperiod (e.g., Newts) and many that are top amphibian predators. In contrast, the natural ephemeral wetlands support amphibians with a shorter larval period (e.g., Wood Frogs). Some ephemeral wetland species will breed in constructed wetlands; thus, there could be negative impacts on these species. Our objectives were to: (1) determine if species of the ephemeral and constructed amphibian communities interact, and (2) evaluate positive and negative impacts on these communities. We selected Eastern Newts (Notophthalmus viridescens) and Wood Frogs (Lithobates sylvaticus) to represent the constructed and natural amphibian communities, respectively. We sampled six constructed and six ephemeral wetlands throughout 2013 and 2014. We counted wood frog egg masses and estimated survival bi-weekly throughout the breeding season (February–May) at each wetland. Newt populations were sampled once in May, July, September, and November, 2013 and January, Febrauary, and March, 2014. Individuals were measured and weighed to determine body condition and individually marked using visual implant elastomer for recapture. Data suggest that wood frog reproductive success is negatively impacted when eggs are laid in constructed wetlands. Newts in constructed wetlands with Wood Frog eggs present had higher body condition. Understanding the impacts of how amphibian species interact as habitat loss and modification increase will continue to be critical for amphibian conservation. Newts in constructed wetlands with wood frogs had a higher BMI than Newts in wetlands without Wood Frog eggs (F1, 743 = 118.027, p < 0.001). Newts in constructed wetlands with wood frog eggs had a higher mass than newts in wetlands without wood frog eggs (Figure 3). Newts in constructed wetlands without wood frog eggs had a higher average SVL compared to newts in wetlands with wood frog eggs. (Figure 4). We used ANCOVA to determine body condition indices (BMI) of captured newts from constructed wetlands. # Clutches Predation (%) 977 C 977 N Big Perry C Big Perry N Elk Lick C Elk Lick N Gas Line C Gas Line N High Energy C High Energy N Jones Ridge C Jones Ridge N The constructed wetlands negatively affect the natural community of amphibians (Denton and Richter 2012) because they might: • Act as a population sink for natural community amphibians due to increased predation. How the communities interact and impact each other are unknown. 0 37 68 54 0 125 89 143 0 76 69 46 Elk Lick 977 High Energy Gas Line Big Perry Jones Ridge Average Absent Average Present 3.6 3.4 3.2 3 0 2.) To evaluate positive and negative impacts on these communities. Late Stage Larva Capture 0 100 10 0 0 68 50 20 0 40 25 50 0 0 0 0 0 0 0 907 0 28 0 82 Absent Overall Present 1 2 3 4 Figure 3. Average mass of newts from each wetland without wood frog eggs (Absent) and with wood frog eggs (Present). An overall average for present and absent are presented with ±1SE. SVL (cm) Mass (g) 1.) To determine if species of the ephemeral and constructed communities interact. Died due to abiotic factors (%) 4 3.8 OBJECTIVES 0 0 70 0 0 0 15 0 0 0 30 0 Wood frogs were negatively impacted by the presence of constructed wetlands and newts. • Wood frogs did not successfully reproduce. • Predation can be one of the most important factors influencing larval survival (e.g., Boone et al. 2004). • Freezing had greater impacts on breeding success in 2012 than the previous 5 years (Richter et al. unpubl. data). Most constructed wetlands are population sinks for wood frogs and potentially ecological traps. Newts benefit from the presence of wood frog eggs. Table 1. The number of wood frog egg masses present and the proportion of egg mortality, due to abiotic factors and predation, at each natural and constructed wetland. (C=Constructed, N=Natural) Wetland CONCLUSIONS • Repeated failure to successfully reproduce can lead to local population declines and extinctions (Semlitsch 2000). Constructed wetlands are different from the natural wetlands because they are: • Permanent water sources (Brown and Richter 2012). • Distinctly different amphibian community compared to ephemeral wetlands (Drayer 2011). Figure 2. (A) Picture of wood frog egg masses. (B) Trap set-up for newt and wood frog capture. 4.8 4.6 4.4 4.2 4 3.8 3.6 3.4 3.2 3 • Due to the extra-food source, newts have an increase BMI in wetlands with wood frogs compared to wetlands without newts. • Prey abundance is related to predator body condition (Pope and Matthews 2002). The presence of permanent water is having a negative impact on most members of amphibians in the natural community. Most of the constructed wetlands should be restored to a more historically accurate hydroperiod. Elk Lick 977 High Energy Gas Line Big Perry Jones Ridge Average Absent Average Present ACKNOWLEDGEMENTS Thank you to Jennifer Strong, Kristin Hinkson, John Bourne, Jesse Godbold, and other undergraduate and gradaute students for help in the field. This research was partially funded by EKU’s Department of Biological Sciences and the Kentucky Academy of Sciences. Research was approved by Eastern Kentucky University Institutional Animal Care and Use Committee protocol No. 05–2013. LITERATURE CITED 0 1 Absent 2 3 Overall Present 4 Figure 4. Average SVL of newts from each wetland without wood frog eggs (Absent) and with wood frog eggs (Present). An overall average for present and absent are presented with ±1SE. Boone, M.D., E.E. Little, R.D. Semlitsch. 2004. Copeia. 2004:683–690. Brown, D.R., and S.C. Richter. 2012. Sustain. 25:22–33. Denton, R.D., and S.C. Richter. 2013. Journal of Wildlife Management. 77:886–889. Drayer, A. 2011. Master’s Thesis. Eastern Kentucky University. Pope, K.L., and K.R. Matthews. 2002. Herpetologica. 58: 354–363. Semlitsch, R.D. 2000. Journal of Wildlife Management. 64:615–631.