Forecasting the effects of accelerated sea-level rise on tidal marsh ecosystem services

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1 Frontiers inecology nd the Environment Forecsting the effects of ccelerted se-level rise on tidl mrsh ecosystem services Christopher Crft, Jonthn Clough, Jeff Ehmn, Smnth Joye, Richrd Prk, Steve Pennings, Hongyu Guo, nd Megn Mchmuller Front Ecol Environ 2009; 7, doi: / This rticle is citble (s shown bove) nd is relesed from embrgo once it is posted to the Frontiers e-view site ( Plese note: This rticle ws downloded from Frontiers e-view, service tht publishes fully edited nd formtted mnuscripts before they pper in print in Frontiers in Ecology nd the Environment. Reders re strongly dvised to check the finl print version in cse ny chnges hve been mde. es The Ecologicl Society of Americ

2 RESEARCH COMMUNICATIONS RESEARCH COMMUNICATIONS Forecsting the effects of ccelerted se-level rise on tidl mrsh ecosystem services Christopher Crft 1, Jonthn Clough 2, Jeff Ehmn 3, Smnth Joye 4, Richrd Prk 5, Steve Pennings 6, Hongyu Guo 6, nd Megn Mchmuller 4 We used field nd lbortory mesurements, geogrphic informtion systems, nd simultion modeling to investigte the potentil effects of ccelerted se-level rise on tidl mrsh re nd delivery of ecosystem services long the Georgi cost. Model simultions using the Intergovernmentl Pnel on Climte Chnge (IPCC) men nd mximum estimtes of se-level rise for the yer 2100 suggest tht slt mrshes will decline in re by 20% nd 45%, respectively. The re of tidl freshwter mrshes will increse by 2% under the IPCC men scenrio, but will decline by 39% under the mximum scenrio. Delivery of ecosystem services ssocited with productivity (mcrophyte biomss) nd wste tretment (nitrogen ccumultion in soil, potentil denitrifiction) will lso decline. Our findings suggest tht tidl mrshes t the lower nd upper slinity rnges, nd their ttendnt delivery of ecosystem services, will be most ffected by ccelerted selevel rise, unless geomorphic conditions (ie grdul increse in elevtion) enble tidl freshwter mrshes to migrte inlnd, or verticl ccretion of slt mrshes to increse, to compenste for ccelerted se-level rise. Front Ecol Environ 2009; 7, doi: / Tidl wetlnds such s slt, brckish, nd freshwter mrshes provide essentil ecosystem services to society. Such services include functions ssocited with regultion, hbitt, nd production (de Groot et l. 2002; Dily et l. 1997). Positioned t the interfce between lnd nd se, tidl mrshes re uniquely suited to provide ecosystem services ssocited with wste tretment, biologicl productivity, nd disturbnce regultion. These services re especilly importnt to the 53% of the US popultion tht lives in the costl zone (Boesch et l. 2000). Tidl mrshes re susceptible to climte chnge, especilly ccelerted se-level rise (SLR). Se level is predicted to increse by cm by 2100, bsed on the Intergovernmentl Pnel on Climte Chnge (IPCC) Specil Report on Emissions Scenrios (SRES; Meehl et l. 2007). The vulnerbility of tidl wetlnds to ccelerted SLR depends on geologic fctors, such s tectonic uplift nd glcil isosttic djustment, which buffer shorelines from SLR, nd subsidence, which ccelertes it. Tide rnge lso ffects mrsh vulnerbility, s mcro- (> 4 m) nd meso-tidl (2 4 m) mrshes re less susceptible to SLR thn re micro-tidl (< 2 m) mrshes (Stevenson nd Kerney in press). In some costl res, rising se level my result in tidl mrsh submergence (Moorhed nd Brinson 1995) nd hbitt migrtion, s slt mrshes trnsgress lndwrd 1 School of Public nd Environmentl Affirs, Indin University, Bloomington IN * (ccrft@indin.edu); 2 Wrren Pinncle Consulting Inc, Wrren, VT; 3 Imge Mtters, Bloomington, IN; 4 Deprtment of Mrine Sciences, University of Georgi, Athens, GA; 5 Eco Modeling, Dimondhed, MS; 6 Deprtment of Biology nd Biochemistry, University of Houston, Houston, TX nd replce tidl freshwter nd brckish mrshes (Prk et l. 1991). Declining tidl mrsh re nd hbitt conversion my led to chnges in delivery of ecosystem services provided by these wetlnds. We used field nd lbortory mesurements, geogrphic informtion systems, nd simultion modeling to predict the effects of ccelerted SLR on tidl mrsh re nd delivery of select ecosystem services long the Georgi cost. Our gol ws to predict how tidl mrsh re nd delivery of ecosystem services would respond to different scenrios of se-level rise during the 21st century. Methods Ecosystem services relted to production (mcrophyte biomss) nd wste tretment (nitrogen [N] ccumultion in soil, potentil denitrifiction) were mesured in two slt mrshes, two brckish mrshes, nd two tidl freshwter mrshes on ech of three rivers long the Georgi cost: the Ogeechee, the Altmh, nd the Still. Mrshes were chosen for this study by exmintion of their dominnt vegettion, which correltes strongly with slinity: on the southestern nd Gulf costs of the US, Sprtin lterniflor domintes in slt mrshes (20 35 ppt [prts slt per thousnd prts wter]), Juncus roemerinus domintes in brckish mrshes (5 20 ppt), nd Zizniopsis milece domintes in tidl freshwter mrshes (< 0.5 ppt). Sprtin spp nd Juncus spp re lso common gener of slt nd brckish mrshes, respectively, in the temperte zone. Aboveground biomss of mcrophytes ws mesured by hrvesting vegettion from 0.25-m 2 qudrts (n = 12 per mrsh) t the end of the seson (October 2006). Nitrogen ccumultion in soil ws determined by collect- The Ecologicl Society of Americ

3 Se-level rise nd tidl mrshes C Crft et l. () Aboveground biomss (g m 2 ) (b) Nitrogen ccumultion (g m 2 yr 1 ) (c) Potentil denitrifiction (ng N 2 O [g dry soil] 1 [hr] 1 ) (0 5 cm) ± ± 112 b 996 ± 152 Tidl fresh Brckish Slt 8.2 ± ± 1 b 2.4 ± 0.4 Tidl fresh Brckish Slt ± 47.6 (6.6 ± 2.7 g N m 2 yr 1 ),b 49.1 ± 23.1 (4.5 ± 2.3 g N m 2 yr 1 ) Tidl fresh Brckish Slt Ogeechee Altmh Still Ogeechee Altmh Still Ogeechee Altmh Still b 21.0 ± 12.3 (1.7 ± 1.1 g N m 2 yr 1 ) Figure 1. () Aboveground biomss, (b) N ccumultion in soil, nd (c) potentil denitrifiction in tidl fresh, brckish, nd slt mrshes of three Georgi river systems (Ogeechee, Altmh, nd Still). Mens shring the sme letter re not significntly different ccording to the Ryn Einot Gbriel Welsch multiple rnge test (p < 0.05). ing two soil cores (8.5-cm dimeter by 50 cm deep) from ech mrsh. Cores were sectioned into 2-cm increments nd ech increment ws nlyzed for bulk density, N concentrtion, nd cesium-137 ( 137 Cs; Crft 2007). Potentil denitrifiction ws mesured in lbortory (sediment slurry) incubtions of soil (n = 4 cores in ech mrsh, tken My 2007) s described by Joye nd Perl (1994). Chnges in tidl mrsh re nd hbitt type in response to ccelerted SLR were modeled using selevel ffects mrshes model (SLAMM version 5), which simultes the dominnt processes involved in wetlnd conversions nd shoreline modifictions during longterm se-level rise (Prk et l. 1989; SLAMM5 integrtes elevtion submergence nd wve ction erosion. SLAMM5 lso incorportes slinity lgorithm, bsed on freshwter dischrge nd cross-sectionl re of the estury, to model sltwter intrusion in river-dominted esturies of our study domin. Model inputs included the USGS Ntionl Elevtion Dtset (NED; ov), NOAA tidl dt, nd USFWS Ntionl Wetlnds Inventory (NWI) dt ( SLAMM5, cell-bsed model, ws run t 28-m resolution bsed on NED chrcteristics within the study region; however, it simultes finer-scled sptil fetures, such s the tll Sprtin mrsh. Model simultions were bsed on the SRES A1B men (39 cm) nd mximum (69 cm) increse in SLR over the next 100 yers, with time step of 25 yers. Becuse the mesured rte of SLR is greter long the Georgin cost (2.5 mm per yer) nd the southestern cost of the US in generl, reltive to the globl verge of 1.8 mm per yer (Church et l. 2001; Peltier 2001), our simultions re bsed on men nd mximum increses of 52 cm nd 82 cm, respectively, by The SRES A1 scenrio ssumes rpid economic growth, low popultion growth, nd rpid introduction of new nd more efficient technology (Church et l. 2001; Meehl et l. 2007). The SRES A2 scenrio, which ssumes lower rte of economic growth nd fewer technologicl dvnces, but greter popultion growth, predicts similr increse in se-level rise during the next century (Church et l. 2001). Delivery of ecosystem services ws scled up by multiplying the hbitt-specific, plot-bsed mesurements (ie mount of mcrophyte biomss, N ccumultion in soil, or potentil denitrifiction per unit re for tidl freshwter, brckish, or slt mrsh) by the totl re of the hbitt types predicted by the model. Chnges in prticulr service re the difference between the totls for two different times (ie initil condition versus 2100 for the scenrios simulted). Results Ecosystem services of tidl freshwter, brckish, nd slt mrshes The vrious hbitts of tidl mrshes provide different quntities of ecosystem services. For exmple, boveground biomss ws 40 70% greter in tidl freshwter nd brckish mrshes thn in slt mrshes (Figure 1). Biomss qulity, bsed on lef C:N, ws lso greter in the tidl freshwter mrsh (34.5 ± 2.8) thn in the brckish mrsh (40.9 ± 1.3) nd slt mrsh (36.4 ± 1.8). Reduced boveground biomss in slt mrshes is linked to greter The Ecologicl Society of Americ

4 C Crft et l. Se-level rise nd tidl mrshes Legend Developed dry lnd Undeveloped dry lnd Hrdwood swmp Cypress swmp Inlnd fresh mrsh Tidl fresh mrsh Trnsitionl soil mrsh Sltmrsh Mngrove Esturine bech Tidl flt Ocen bech Ocen flt Rocky intertidl Inlnd open wter Riverine tidl Esturine open wter Tidl creek Open ocen Brckish mrsh Tll Sprtin Freshwter shore Tidl swmp Figure 2. SLAMM simultion of effects of ccelerted SLR on tidl mrshes of the Altmh River, Georgi. The simultion ws run using the SRES A1B scenrio tht ssumes 52-cm increse in se level by The corse verticl resolution of the NED dtset results in the liner pttern (ie striping) of wetlnd migrtion observed during the simultion. Simultion modeling predicts tht 52-cm increse in se level will led to decline in tidl mrsh re nd delivery of ecosystem services long the Georgi cost during this century. To illustrte, Figure 2 depicts SLAMM simultion results for the Altmh River. For this river system, the model predicts lrge decline in re of tidl freshwter mrsh ( 38%) nd swmp ( 24%), smller decline of slt mrsh ( 8%), nd smll increse in brckish mrsh hbitt (+4%). A correslinity nd sulfide stress, which inhibits N uptke nd reduces plnt growth (Odum 1988; Mendelssohn nd Morris 2000). Tidl freshwter nd brckish mrshes lso provided greter wste tretment per unit re thn did slt mrshes (Figure 1). These mrshes sequestered three times more N in soil nd supported two to three times greter potentil denitrifiction thn slt mrshes. Greter N ccumultion nd potentil denitrifiction in tidl freshwter nd brckish mrsh soils is linked to low levels of slinity. In tidl mrsh soils, decomposition is positively relted to slinity, such tht orgnic mtter nd N ccumultion re reduced in slt mrsh soils reltive to brckish nd tidl freshwter mrshes (Crft 2007). Slinity lso hinders denitrifiction by inhibiting nitrifying bcteri tht convert mmonium to nitrte (Joye nd Hollibugh 1995) nd by fvoring sulfte-reducing bcteri tht my outcompete denitrifiers for vilble lbile crbon substrtes (Weston et l. 2006). Effect of ccelerted SLR on tidl mrsh re nd ecosystem services The Ecologicl Society of Americ

5 Se-level rise nd tidl mrshes C Crft et l. Tble 1. Predicted chnge in re (km 2 ) of selected lnd-cover types long the Georgi cost, in response to the A1B SRES se-level rise scenrio s modeled by SLAMM A1B men = 52 cm A1B mx = 82 cm % chnge % chnge Dry lnd Non-tidl swmp Tidl swmp Inlnd fresh mrsh Tidl fresh mrsh Brckish mrsh Slt mrsh Trnsitionl slt mrsh Tidl flt Esturine open wter Notes: The simultion ws run ssuming the men (52 cm) nd mximum (82 cm) increse in se level between 1999 nd Differences in the initil res of lnd-cover types between the A1B men nd mx simultions re the result of using IPCC projections tht begin in 1990 nd, thus, led to smll differences in the initil conditions bsed on the scenrio (men versus mx) chosen. 1 High mrsh shrub vegettion flooded only during spring tides nd storm tides. sponding increse in trnsitionl slt mrsh (+780%, from 8 to 68 km 2 ), tidl flt (+400%, from 1 to 5 km 2 ), nd esturine open wter (+52%, from 176 to 268 km 2 ) lso occurs s se level rises (Figure 2). For the entire Georgi cost, 52-cm increse in se level cuses overll reduction in slt mrsh ( 20%), long with smll increse in tidl freshwter mrsh (+2%) nd lrger increse in brckish mrsh (+10%; Tble 1). The decline in slt mrsh is ttributed to submergence nd replcement by tidl flts nd esturine open wter (Tble 1). The increse in tidl freshwter mrsh nd brckish mrsh occurs t the expense of tidl swmp, which declines by 24% s these mrshes migrte up-river in response to se-level rise nd sltwter intrusion. Overll, there is net loss of tidl mrsh hbitt (184 km 2 ), s slt mrsh hbitt declines by 226 km 2, while brckish mrsh nd tidl freshwter mrsh increse by 41 km 2 nd 1 km 2, respectively (Tble 2). By combining mesurements of ecosystem services with the chnge in tidl mrsh hbitt, we cn predict how delivery of ecosystem services is ffected by ccelerted SLR. As tidl mrsh hbitt declines, delivery of ecosystem services relted to productivity nd N retention nd removl re reduced. Aboveground biomss of mcrophytes is reduced by more thn metric tons (t) per yer under the A1B men scenrio (Tble 2). Nitrogen sequestrtion in soil is reduced by 227 t per yer, wheres potentil denitrifiction is reduced by 193 t per yer. The cumultive reduction in delivery of ecosystem services is ttributed mostly to loss of slt mrsh hbitt, even though tidl freshwter mrsh nd brckish mrsh provide greter delivery of ecosystem services thn do slt mrshes on per-unit-re bsis. An 82-cm increse in se level, predicted by the A1B mximum scenrio, leds to even greter reduction in tidl mrsh re nd delivery of ecosystem services. Bsed on this scenrio, tidl freshwter, brckish, nd slt mrshes decline by 39%, 1%, nd 45%, respectively, by Delivery of ecosystem services is lso drmticlly reduced under the A1B mximum scenrio, s mcrophyte biomss Tble 2. Predicted chnge in tidl mrsh re nd delivery of select ecosystem services long the Georgi cost between 1999 nd 2100 in response to 52-cm nd 82-cm increse in se level Hbitt chnge Mcrophyte biomss N sequestrtion in soil Potentil denitrifiction (km 2 ) (t yr 1 ) (t yr 1 ) (t yr 1 ) 52 cm 82 cm 52 cm 82 cm 52 cm 82 cm 52 cm 82 cm Tidl fresh mrsh Brckish mrsh Slt mrsh Cumultive (km 2 ) Cumultive (%) 11% 33% 8% 28% 4% 23% 4% 25% Notes: Chnge in delivery of ecosystem services ws clculted by multiplying the chnge in hbitt re by the men ecosystem service vlues for ech mrsh type in Figure 1. Negtive vlues denote reduction in mrsh re nd delivery of ecosystem services. The Ecologicl Society of Americ

6 C Crft et l. Se-level rise nd tidl mrshes decreses by nerly t per yer, N ccumultion in soil decreses by 1482 t N per yer, nd potentil denitrifiction declines by 1072 t N per yer (Tble 2). Under the A1B men nd mximum SLR scenrios, cumultive tidl mrsh re declines by 12% nd 33%, respectively, while cumultive reduction in delivery of ecosystem services is 4 28% lower (Tble 2). Delivery of ecosystem services is less ffected by ccelerted SLR thn is tidl mrsh re, becuse brckish mrsh re, which hs high delivery of services per unit re, does not chnge substntilly ( 1% to +10%) reltive to slt mrshes tht decline in re by 20 45%. This result highlights n unpprecited vlue of brckish mrshes: becuse they support high levels of ecosystem services nd do not decline s much s other tidl mrsh types, they my buffer some of the negtive impcts of SLR. Sensitivity nlysis of model prmeters We conducted sensitivity nlysis by vrying model prmeters, historic rte of SLR, site-specific ccretion rtes for slt mrsh, brckish mrsh, nd tidl freshwter mrsh, nd erosion rtes for tidl flt nd slt mrsh by plus or minus 15%, to determine which prmeters most ffect model output when compring results fter 69 cm of eusttic (worldwide) SLR (82 cm for Georgi). Model results were most sensitive to chnges in the historic rte of locl SLR, which ffects long-term projections of locl SLR. Incresing this prmeter by 15% decresed slt mrsh nd tidl freshwter mrsh re by 7.3% nd 13%, respectively, nd tidl flt re incresed by 12%. Model output ws less sensitive to sitespecific ccretion nd erosion rtes. Decresing ccretion rtes by 15% resulted in 7% decrese in slt mrsh re nd 5% decrese ech in brckish mrsh nd tidl freshwter mrsh re. Incresing tidl flt erosion rte by 15% resulted in n 18% decrese in this hbitt type. Discussion Limittions of the pproch Severl cvets ssocited with the tools nd pproches we used deserve mention. First, uncertinties exist with scling results from lbortory nd plot mesurements to the lndscpe level. Second, there re limittions ssocited with the dt inputs used in the SLAMM5 SLR simultions. For exmple, NED elevtion dt covering the entire cost hve only moderte resolution. Third, the SLAMM5 model lcks feedbck mechnisms tht my come into ply s SLR ccelertes. For exmple, incresing inundtion of slt mrshes my increse mcrophyte production nd led to incresed verticl ccretion (Morris et l. 2002). Conversely, incresing sltwter intrusion into tidl freshwter mrshes my ccelerte decomposition (Weston et l. 2006), leding to reduced verticl ccretion. Despite these cvets, our pproch provides importnt insights into how ccelerted SLR my ffect tidl mrshes nd their delivery of ecosystem services in the future. Beyond the southest cost Although our simultion focuses on the Georgi cost, we speculte tht, elsewhere, tidl freshwter nd slt mrshes will lso be most ffected by SLR. Tidl freshwter mrshes will decline in re s sltwter intrudes nd brckish mrshes migrte inlnd to replce them. Slt mrshes will convert to open wter becuse their low rte of verticl ccretion reltive to brckish nd tidl freshwter mrshes (Crft 2007) my prevent them from keeping pce with ccelerted SLR. Declining re of tidl freshwter wetlnds, mrshes, nd swmp forests (Tble 1) my be problemtic for the Americn lligtor (Alligtor mississippiensis), wood stork (Mycteri mericn), nd other species tht depend on freshwter qutic hbitts. On per-unit-re bsis, tidl freshwter wetlnds provide higher levels of ecosystem services thn do slt mrshes, so their decline will led to disproportionte decrese in delivery of ecosystem services. In the 21st century, these problems will probbly be compounded by reduced river dischrge cused by the greter climte vribility (eg droughts) tht will ccompny globl wrming (Meehl et l. 2007), nd by incresed demnd for freshwter by growing humn popultion. At the sme time, declining re of slt mrsh my led to reduced shoreline protection nd hbitt support for mrsh nekton (free swimming qutic nimls; Kneib 2000), lthough incresing mrsh edge my enhnce nekton ccess to the remining mrsh (Zimmermn et l. 2000). Our predictions of the effects of ccelerted SLR on the delivery of tidl mrsh ecosystem services of the Georgi cost should be viewed with cution, becuse the drivers of climte chnge, greenhouse gses (nd temperture), will lso increse. Incresing CO 2 nd temperture over the next century my lter plnt physiologicl processes tht ffect the distribution nd productivity of plnt communities. For exmple, incresing CO 2 my fvor incresed productivity nd wter-use efficiency, especilly by C 3 vegettion, which my led to chnges in plnt community composition nd productivity (Körner 2006). Nitrogen ccumultion in soil my be ltered by incresed temperture nd lower N demnd from vegettion s result of higher CO 2 (Curtis et l. 1990). Forecsted chnges in tidl mrsh re nd delivery of ecosystem services re pplicble to other temperte res, where tidl mrshes experience meso-tidl inundtion nd where rtes of SLR re comprble (ie 2 3 mm per yer). Some costl regions experience tectonic uplift nd there, tidl mrshes re not s vulnerble. Worldwide, there is evidence tht tidl mrshes in flooddominted esturies, or those tht receive high sediment lods, my be better buffered ginst SLR thn mrshes in ebb-dominted or low sediment supply esturies (Morris The Ecologicl Society of Americ

7 Se-level rise nd tidl mrshes et l. 2002; Stevenson nd Kerny in press). In regions where subsidence is occurring, tidl mrshes re t greter risk. Mrshes exposed to micro-tidl (< 2 m) inundtion re lso likely to suffer greter declines in re nd delivery of ecosystem services thn re meso-tidl (2 4 m inundtion) mrshes, becuse they rely more on orgnic mtter ccumultion to support verticl ccretion nd, thus, my not be ble to compenste for ccelerted SLR (Stevenson nd Kerney in press). On positive note, Georgi s tidl mrshes experience meso-tidl inundtion (tide rnge = 2.3 m), which buffers them ginst moderte increses in se level, s they my be ble to increse their rte of verticl ccretion to compenste (Morris et l. 2002). Thus, the decline in slt mrsh hbitt my not be s gret s predicted by our model simultions. In summry, our results suggest tht slt, brckish, nd tidl freshwter mrshes of the Georgi cost will respond differently to 52-cm increse in SLR, with fresh nd slt mrshes suffering greter losses thn brckish mrshes. Becuse brckish mrshes provide ecosystem services t rte greter thn tht of other mrsh types, nd becuse brckish mrshes re predicted to undergo less precipitous declines in re thn other mrsh types, the predicted loss of ecosystem services long the Georgi cost is less thn would be forecst bsed solely on losses in totl mrsh re. Acknowledgements This work ws supported by the US Environmentl Protection Agency Science to Achieve Results (STAR) progrm grnt number RD to CC nd Ntionl Science Foundtion grnt #OCE to the Georgi Costl Ecosystems Long Term Ecologicl Reserch progrm. This is contribution number 964 from the University of Georgi Mrine Institute. C Crft et l. References Boesch DF, Field JC, nd Scvi D (Eds) The potentil consequences of climte vribility nd chnge on costl res nd mrine resources. Wshington, DC: US Deprtment of Commerce. NOAA s Costl Ocen Progrm, Decision Anlysis Series No 21. Church JA nd Gregory JM Chnges in se level. In: Houghton JT, Ding Y, Griggs DJ, et l. (Eds). Climte chnge 2001: the scientific bsis. Contribution of Working Group I to the third ssessment report of the Intergovernmentl Pnel on Climte Chnge. Cmbridge, UK: Cmbridge University Press. Crft CB Freshwter input structures soil properties, verticl ccretion nd nutrient ccumultion of Georgi nd United Sttes (US) tidl mrshes. Limnol Ocenogr 52: Curtis PS, Bldumn LM, Drke BG, nd Whighm DF Elevted tmospheric CO 2 effects on belowground processes in C 3 nd C 4 esturine mrsh communities. Ecology 71: Dily GC, Alexnder S, Ehrlich PR, et l Ecosystem services: benefits supplied to humn societies by nturl ecosystems. Issues Ecol 2: de Groot RS, Wilson MA, nd Boumns RJM A typology for the clssifiction, description nd vlution of ecosystem functions, goods nd services. Ecol Econ 41: Joye SB nd Hollibugh JT Influence of sulfide inhibition of nitrifiction on nitrogen regenertion in sediments. Science 270: Joye SB nd Perl HW Nitrogen cycling in microbil mts: rtes nd ptterns of denitrifiction nd nitrogen fixtion. Mr Biol 119: Kneib RT Slt mrsh ecoscpes nd production trnsfers by esturine nekton in the southestern United Sttes. In: Weinstein MP nd Kreeger DA (Eds). Concepts nd controversies in tidl mrsh ecology. Dordrecht, Netherlnds: Kluwer Acdemic Publishers. Körner C Plnt CO 2 responses: n issue of definition, time nd resource supply. New Phytol 172: Meehl GA, Stocker TF, Collins WD, et l Globl climte projections. In: Solomon S, Qin D, Mnning M, et l. (Eds). Climte chnge 2007: the physicl science bsis. Contribution of Working Group I to the fourth ssessment report of the Intergovernmentl Pnel on Climte Chnge. Cmbridge, UK: Cmbridge University Press. Mendelssohn IA nd Morris JT Ecophysiologicl controls on the productivity of Sprtin lterniflor Loisel. In: Weinstein MP nd Kreeger DA (Eds). Concepts nd controversies in tidl mrsh ecology. Dordrecht, Netherlnds: Kluwer Acdemic Publishers. Moorhed KK nd Brinson MM Response of wetlnds to rising se level in the lower costl plin of North Crolin. Ecol Appl 5: Morris JT, Sundreshwr PV, Nietch CT, et l Response of costl wetlnds to rising se level. Ecol Appl 83: Odum WE Comprtive ecology of tidl freshwter nd slt mrshes. Annu Rev Ecol Syst 19: Prk RA, Lee JK, Musel PW, nd Howe RC Using remote sensing for modeling the impcts of se level rise. World Resour Rev 3: Prk RA,Trehn MS, Musel PW, nd Howe RC The effects of se level rise on US costl wetlnds. In: Smith JB nd Tirpk DA (Eds). The potentil effects of globl climte chnge on the United Sttes. Appendix B se-level rise. Wshington, DC: US Environmentl Protection Agency. Peltier WR Globl glcil isosttic djustment nd modern instrumentl records of reltive se level history. In: Dougls BC, Kerney MS, nd Lethermn SP (Eds). Se-level rise: history nd consequences. Sn Diego, CA: Acdemic Press. Stevenson JC nd Kerney MS. Impcts of globl climte chnge nd se level rise on tidl wetlnds. In: Sillimn BR, Bertness MD, nd Strong D (Eds). Anthropogenic modifiction of North Americn slt mrshes. Berkeley, CA: University of Cliforni Press. In press. Weston NB, Dixon RE, nd Joye SB Rmifictions of slinity intrusion in tidl freshwter sediments: geochemistry nd microbil pthwys of orgnic mtter minerliztion. J Geophys Res-Biogeosci 111: G0100. doi: /2005jg Zimmermn RJ, Minello TJ, nd Rozs LP Slt mrsh linkges to productivity of peneid shrimps nd blue crbs in the northern Gulf of Mexico. In: Weinstein MP nd Kreeger DA (Eds). Concepts nd controversies in tidl mrsh ecology. Dordrecht, Netherlnds: Kluwer Acdemic Publishers. The Ecologicl Society of Americ