Abstract
Anthropogenic nitrogen (N) enrichment can have complex effects on plant communities. In low-nutrient, primary successional systems such as sand dunes, N enrichment may alter the trajectory of plant community assembly or the dominance of foundational, ecosystem-engineering plants. Predicting the consequences of N enrichment may be complicated by plant interactions with microbial symbionts because increases in a limiting resource, such as N, could alter the costs and benefits of symbiosis. To evaluate the direct and interactive effects of microbial symbiosis and N addition on plant succession, we established a long-term field experiment in Michigan, USA, manipulating the presence of the symbiotic fungal endophyte Epichloë amarillans in Ammophila breviligulata, a dominant ecosystem-engineering dune grass species. From 2016 to 2020, we implemented N fertilization treatments (control, low, high) in a subset of the long-term experiment. N addition suppressed the accumulation of plant diversity over time mainly by reducing species richness of colonizing plants. However, this suppression occurred only when the endophyte was present in Ammophila. Although Epichloë enhanced Ammophila tiller density over time, N addition did not strongly interact with Epichloë symbiosis to influence vegetative growth of Ammophila. Instead, N addition directly altered plant community composition by increasing the abundance of efficient colonizers, especially C4 grasses. In conclusion, hidden microbial symbionts can alter the consequences of N enrichment on plant primary succession.
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Introduction
Anthropogenic nitrogen (N) enrichment from agriculture, industry, wastewater, and fossil fuel combustion has more than doubled rates of nitrogen input into the terrestrial nitrogen cycle (Vitousek et al. 1997; Galloway et al. 2008; Fowler et al. 2013), which threatens terrestrial biodiversity and ecosystem functioning (Cleland and Harpole 2010; Su et al. 2022). One component of this enrichment, atmospheric N deposition, has increased nearly threefold in terrestrial systems from 1850 to the present day (Kanakidou et al. 2016), and is predicted to continue to increase during the coming decades (Lamarque et al. 2013; Ciais et al. 2013). Such N enrichment is a complex form of stress for plants because resource addition can have positive or negative effects. For example, N addition can increase plant productivity and fitness (Huberty et al. 1998; Xia and Wan 2008; Guo et al. 2022). Conversely, N inputs can decrease biodiversity due to increased dominance by highly competitive plant species (Stevens et al. 2004; Bobbink et al. 2010; Gross and Mittelbach 2017; Payne et al. 2017).
Reductions in plant community diversity under N enrichment have been well documented in secondary successional systems, such as old fields (Tilman 1987; Huberty et al. 1998; Crawley et al. 2005; Midolo et al. 2019), but much less studied in low-nutrient, successional ecosystems, where N impacts could be strongest (Sparrius et al. 2012). Nutrient inputs could affect foundational ecosystem-engineering plants during early succession, then cascade to alter plant community assembly and ecosystem function (Day et al. 2004, 2018). For example, atmospheric N deposition promoted the ecosystem-engineering grass, Ammophila arenaria, in dunes of the United Kingdom by increasing grass height and cover, which in turn was associated with decreased plant species richness (Jones et al. 2004).
Predicting how N enrichment affects early succession is more complicated if nutrients alter interactions between microbial symbionts and ecosystem-engineering plants. Increasing a limiting resource, such as N, commonly reduces the benefits of plant–microbe symbioses, particularly those in nutritional mutualisms (reviewed by Kivlin et al. 2013). Symbionts such as mycorrhizal fungi in plant roots can become parasitic with nutrient additions (Johnson et al. 2010; Hoeksema et al. 2010). Increased nutrients can also diminish the biomass of fungal partners by reducing carbon investments from the host plant (Hoeksema et al. 2010; Wipf et al. 2019). Additionally, N enrichment can suppress ecosystem-engineering plants such as nitrogen-fixing lupines, by selecting for less cooperative rhizobia mutualists and reducing plant fitness (Titus 2009; Weese et al. 2015). Alternatively, N addition can cause leaf endophytes, such as Epichloë spp., to increasingly benefit host plants as energetic costs of the symbiosis are reduced, and production of N-rich alkaloids that protect plants from herbivory are increased (Lane et al. 1997; Krauss et al. 2007; Hager et al. 2021). In successional ecosystems, such interactions with microbial symbionts could affect the dominance of ecosystem-engineering plants, indirectly changing facilitative or inhibitory interactions that influence rates or trajectories of early succession.
Coastal sand dunes may experience strong impacts of nutrient enrichment on succession through microbial symbioses due to their low nutrient availability and low diversity plant communities dominated by ecosystem engineers. Coastal habitats are threatened by N enrichment because of their proximity to major urban centers and hydrological connections to terrestrial watersheds via river outflows (Crossett et al. 2004; Howarth 2008; Malone and Newton 2020). The U.S. Great Lakes coastal region has high N enrichment due to agricultural, atmospheric, and point-source inputs (Morrice et al. 2008; National Atmospheric Deposition Program 2022). For example, atmospheric N deposition, especially the concentration of NH4+, into Great Lakes ecosystems have increased by 400% from historic levels (Du et al. 2014), while dissolved inorganic N in Great Lakes coastal wetlands has risen as a direct result of row-crop agriculture and urbanization in the region (Morrice et al. 2008; Harrison et al. 2020). Understanding potential changes to Great Lakes ecosystems is essential for conservation of these ecosystems in the future.
In the Great Lakes region and North Atlantic Coast, Ammophila breviligulata, American beach grass (hereafter Ammophila), is the primary dune ecosystem-engineering plant (Garguillo et al. 2004). Ammophila can facilitate colonization by other plant species by stabilizing sand and ameliorating harsh physical conditions (Cowles 1899; Zarnetske et al. 2012). However, Ammophila can also inhibit succession through plant competition (Cheplick 2005; Hastings et al. 2007), and Ammophila die-off is an important stage in dune succession (Maun and Lapierre 1984; Voesenek et al. 1998). Past work demonstrated that nutrient additions increased Ammophila growth (Day et al. 2004, 2018), which could alternatively promote abundance and diversity of later colonizers through sand stabilization, or reduce diversity through amplified plant competition. Ammophila also hosts the vertically transmitted, systemic fungal endophyte Epichloë amarillans (Drake et al. 2018), hereafter Epichloë. Epichloë is present in approximately one-third of Ammophila populations in surveyed Great Lakes sites (Emery and Rudgers 2014) and in nearly all commercially available plants used for restoration (Emery and Rudgers 2010). Our past experimental work showed that Epichloë benefited Ammophila during the first years of dune succession by increasing aboveground and belowground growth and increasing sand accumulation. Additionally, Epichloë presence in Ammophila reduced colonizing plant diversity, most likely due to increased Ammophila density (Emery et al. 2015; Rudgers et al. 2015; Bell-Dereske et al. 2017). Although Epichloë symbiosis has clear ecological impacts on early succession in dunes, the longer-term effects of symbiosis and potential for interactions with nitrogen enrichment remain unknown for this oligotrophic and ecologically important ecosystem.
To evaluate the direct and interactive effects of microbial symbiosis and N addition on dune succession, we used a long-term field experiment to ask: Does N addition alter plant community succession? And if so, is this due to any effects of N addition on growth of Ammophila, or through changes to the Ammophila-Epichloë symbiosis? We hypothesized that N addition would directly decrease plant community diversity by allowing the best competitors to colonize and dominate the community, as shown in secondary successional ecosystems (Foster and Gross 1998; Crawley et al. 2005). Alternatively, N addition could increase plant diversity by releasing colonizing plants from extreme N limitation and promoting their initial establishment. Indirectly, N addition could increase density of Ammophila and slow Ammophila die-off (Day et al. 2004), reducing the diversity of later colonizing species and slowing successional change. We expected that the presence of Epichloë would interact with N addition to enhance the dominance of Ammophila because prior studies on other Epichloë symbioses generally report benefits of N to the symbiosis (reviewed by Kivlin et al. 2013). Thus, we hypothesized that the combined effects of N addition and Epichloë would slow plant succession and suppress diversity even more than either factor alone.
Methods
Experimental design
In May 2010, we established a factorial field experiment on a bare dune blowout approximately 200 m from the shoreline of Lake Michigan in Leelanau State Park, Michigan, USA (45810.9640 N, 85834.5780 W). This location experiences annual precipitation of 817 mm/year and an average temperature of 7.6 °C (PRISM 2012). Common plants found within this parabolic dune complex are Ammophila breviligulata, Schizachyrium scoparium, Calamavilfa longifolia, Cirsium pitcheri, Artemesia campestris (Albert 2000). To manipulate the presence or absence of Epichloë in Ammophila, we used endophyte-free seeds collected from nearby dunes, germinated seedlings of Ammophila in the lab, and either artificially inoculated seedlings with Epichloë (E+) or sham inoculated them with sterile water (E-); see details in Emery et al. (2015). Plants were clonally propagated in a greenhouse and then transported to the field. In each of 90 2 m × 2 m plots, we transplanted 25 E+ or 25 E− Ammophila plants and monitored plots yearly from 2010–2020.
Because plants can sometimes lose endophyte symbionts over time (Rudgers et al. 2009; David et al. 2019), we used commercial immunoblot kits (Phytoscreen: Agrinostics, Watkinsville, GA) to assess treatment fidelity in two tillers per plot in 2019. Any inconclusive assay results were followed up with microscopy to confirm presence or absence of hyphae within leaf tissue. In 2019, 91% of E+ treatment plot tillers maintained evidence of Epichloë infection, while 89% of E− plot tillers still lacked Epichloë.
N fertilization treatments
During 2016, we introduced N fertilization treatments to a subset of 60 plots in the long-term experiment (30 E+ and 30 E− plots). One third of plots (10 each E+ and E−) received a low level of N (0.5 g NH4+ m−2), corresponding to current atmospheric N deposition rates found near the Chicago, IL urban center (Du et al. 2014), another third received high levels of N (10 g NH4+ m−2), comparable to other N addition experiments focused on releasing plants from nutrient stress (e.g., Borer et al. 2014), and the last set of plots received no added N (control). We added N as urea slow-release fertilizer (ESN Urea coated fertilizer: Nutrient Ltd., New Madrid MO), applied twice yearly, once in May at the beginning of the growing season, and again mid-season in July. Due to COVID-19 travel restrictions, we were unable to apply fertilizer in May 2020, but treatments resumed as planned in July 2020. Every July from 2016 to 2020, we collected data on plant diversity and abundance in all plots. Specifically, we recorded Ammophila tiller density (tillers m−2) and the number and identity of all non-Ammophila colonizing plant individuals across the entire plot to calculate total colonizer abundance, species richness, Shannon diversity (H′), and Shannon evenness (E′) per plot for each year of data collection. Diversity and evenness measurements were density-based, calculated from counts of each individual per treatment plot. Species present in these plots, other than the initially planted Ammophila, all colonized naturally. Additionally, all treatment plots were randomized completely to avoid potential effects of biased distribution of seeds or propagules came from heterogeneous seed bank and rain.
Statistical analysis
To evaluate whether N addition and endophyte presence synergistically affected plant successional dynamics, we conducted plot level comparisons of plant community structure over time. First, we used general linear mixed-effects models to examine the responses of plant diversity (H′), species richness, community evenness (E′) and Ammophila tiller density to the fixed effects of year, nitrogen fertilization treatment, and endophyte presence, with random effects of plot and spatial factors (row and column within the grid of 90 plots) using function lme in the <nlme> package (Pinheiro et al. 2017). Focusing on year × N fertilization × endophyte effects, we applied model selection based on the second-order Akaike information criterion (Burnham and Anderson 1998) to compare a simple model assuming independence of observations across years against models with temporal autocorrelation (either autoregressive 1 or autoregressive 2) (Pinheiro et al. 2017). AICc values were obtained with the MuMIn package (Barton and Anderson 2015), and results are reported from the model with the lowest AICc. We determined marginal R2 values of the best models using rsquared in piecewiseSEM (Lefcheck 2016).
Second, we used PERMANOVA to analyze changes in community composition (Clarke and Gorley 2009). PERMANOVA models included fixed effects of year, nitrogen fertilization level, and endophyte presence or absence, and the random effect of plot. PERMANOVA used the Bray–Curtis distance metric with 9999 permutations under a reduced model with Type III SS. We then used pairwise tests to evaluate which treatment combinations differed significantly in plant community composition, with the specific prediction that the combined effects of N fertilization and endophyte presence would be non-additive. We visualized compositional differences in the abundance of plant species using nonlinear multidimensional scaling (NMDS) analysis. The community matrix was constructed with count data, relating to plant species densities within treatment conditions. Third, heterogeneity of the community in response to the different treatment factors that were indicated as significant in the PERMANOVA was tested using PERMDISP (Anderson 2006), which examines whether treatments differ in the degree of dissimilarity of community composition among replicated plots (e.g., the spread in composition represented by the NMDS graph). Finally, a SIMPER analysis was used to rank plant species by their relative contributions to differences among treatment combinations in community composition in order to identify which species were the strongest drivers of change in the dune plant community (Clarke and Gorley 2009).
Results
Plant community diversity
Overall, nitrogen fertilization and endophyte presence interacted to suppress plant diversity (Table 1). Compared to control plots, plant community diversity (H’) was 7% lower in the low nitrogen addition treatment and 17% lower under high nitrogen addition, but only if Epichloë was present (Fig. 1a, Online Resource 1). N additions did not significantly affect diversity in the absence of Epichloë. The decline in diversity was mainly due to decreased plant species richness, which was reduced by 20% under high nitrogen, but again only if Epichloë was present (Table 1, Fig. 1b, Online Resource 1). The response of plant community evenness (E’) was more variable than that of species richness, and significantly declined under nitrogen fertilization only when Epichloë was absent (opposite to the response of richness) and then only in 2017 (Table 1, Fig. 1c, Online Resource 1).
Plant community composition
N fertilization shifted overall plant community composition, starting 2 years after the N addition treatments began (Table 1, Fig. 2). Low N communities differed from control treatment communities starting in 2018 (pairwise post-hoc tests not shown), and high N communities differed from control communities starting in 2017, although communities treated with high or low N addition did not differ from each other in any year. High N addition also increased heterogeneity (dispersion) in plant species composition among plots by 26% compared to controls, which had more consistent plant composition across the 10 replicate plots (Table 1). The SIMPER analysis indicated that changes in composition were due to grasses increasing and forbs declining in nitrogen addition plots (Online Resource 2). Specifically, Schizachyrium scoparium increased by 8%, Calamovilfa longifolia increased by 81%, and Agropyron cristatum increased by 121% with high N addition, while Artemisia campestris declined by 76%, and Cirsium pitcheri declined by 23%. Epichloë presence had no effect on community composition (Table 1).
Ammophila density
Ammophila density declined steadily from 2016–2020 (approximately 19% each year), corresponding to the Ammophila die-off that occurs during later stages of dune succession (Fig. 3). Increased resource availability in the form of N addition only altered tiller density in one of the 5 years of the study (Table 1, Fig. 3, Online Resource 1). In 2018, low and high N addition increased tiller numbers by 24–25%. Effects of N addition were non-significant in 2016, 2017, 2019, and 2020 (Online Resource 1). Despite small N fertilization effects, Ammophila maintained 19% higher tiller density on average over time when Epichloë was present (Fig. 3). There were no significant interactive effects of endophyte presence and N addition (Table 1).
Discussion
N and Epichloë effects on plant community succession
N addition in this freshwater dune system suppressed plant species diversity over time mainly by reducing species richness of the colonizing plant community. However, these effects occurred only when the systemic foliar endophyte Epichloë was present in Ammophila. Our results from this early successional system are consistent with the observation that high levels of N addition that release plants from nutrient stress reduce plant species richness and evenness of later successional plant communities (Bobbink et al. 2010; Borer et al. 2017; Seabloom et al. 2021). Low levels of N addition, corresponding to more realistic atmospheric N-deposition scenarios, have had mixed effects on plant communities in prior studies (Clark and Tilman 2008; Humbert et al. 2016; Midolo et al. 2019). Therefore, it is notable that even the low N addition treatment in our experiment significantly reduced plant community diversity, indicating that even small increases in anthropogenic N deposition may alter the trajectory of succession in dunes where Epichloë is present. This interaction may be due to the suppressive effect that Epichloë presence had on colonizing plant diversity in the initial years of this experiment, before N addition treatments started (Rudgers et al. 2015). This is particularly relevant in the context of dune restoration since commercial Ammophila plants used in many restorations in both the Great Lakes region and the Eastern US have Epichloë infections, while the majority of natural Great Lakes populations lack symbiosis with Epichloë (Emery and Rudgers 2010, 2014). Alternatively, symbioses Epichloë are known to enhance secondary metabolite production within plant hosts, specifically alkaloids. Alkaloids are nitrogen-based chemicals, therefore increased nitrogen could increase host production of these secondary metabolites (Lane et al. 1997; Krauss et al. 2007) which could in turn suppress the establishment of later colonizing species.
N fertilization at either high or low levels had direct effects on plant community composition, independent of whether Epichloë was present, which contrasts against the interaction between N addition and endophyte symbiosis on plant diversity. This was in part due to N addition increasing the spatial heterogeneity of plant communities, causing replicate plots to diverge more in species composition over time. Decreased species richness paired with increased local heterogeneity (dispersion) is a common result of fertilization studies, especially in low-productivity systems (Chalcraft et al. 2008) and this may contribute to temporal stability of these ecosystems (Zhou et al. 2019; Zhang et al. 2019). It is possible for side-effects of fertilization, such as reduced soil pH, to act as environmental filters decreasing plant community heterogeneity in low-productivity systems (Liu et al. 2021). However, changing soil pH is a natural part of early succession in these dunes systems as carbonate minerals dissolve (Lichter 1998). There can be complicated relationships between fertilization, diversity, and time in successional systems (Inouye and Tilman 1995), and more work is needed to understand the consequences of changes in community heterogeneity for successional dynamics.
Additional changes in community composition in response to N addition were due to changes in the abundances of particular species. Two native C4 grass species, Schizachyrium scoparium and Calamovilfa longifolia, and one non-native C3 grass species, Agropyron cristatum, increased under N addition, while two native forbs declined (Artemisia campestris and Cirsium pitcheri). The increase in grass abundance under N addition may suggest that N reduced the intensity of competition for nutrients with Ammophila, especially for the most functionally similar grasses. This phenomenon is well-supported by other studies. In a meta-analysis conducted for grasslands, N addition similarly increased the biomass of grasses and decreased that of forbs (You et al. 2017). Likewise, in secondary successional grasslands, N addition increased growth of C4 grasses and tall clonal species at the expense of C3 grasses and forbs (Suding et al. 2005; Clark et al. 2007; Gross and Mittelbach 2017). N addition was specifically associated with increased abundance of the late-successional grass Schizachyrium scoparium in Great Lakes oak-savannah/sand-prairie systems as well (Bird and Choi 2017). In the Great Lakes dunes, both Schizachyrium scoparium and Calamovilfa longifolia are important successional species, replacing Ammophila as dunes stabilize (Olson 1958). However, increased dominance of these grasses in areas with high N enrichment may drive down the abundance of forbs which provide unique biodiversity in this system. In particular, Cirsium pitcheri is a federally threatened species that is endemic to Great Lakes dunes and thrives in habitats with moderate levels of sand burial (Pavlovic et al. 1998; Rowland and Maun 2001). This species is already threatened by lakeshore erosion, human disturbance, and climate change (Staehlin and Fant 2015). While this species is known to respond positively to N fertilizer in a greenhouse context (Rowland and Maun 2001), increased dominance by later-successional grass species in response to N deposition appears to inhibit Cirsium pitcheri germination and growth in realistic field settings.
N addition is also known to increase the abundances of non-native plant species in communities, which may explain the increase in A. cristatum abundance. Agropyron cristatum is a non-native grass that is invasive in western US rangelands (Christian and Wilson 1999), and is naturalized in dune habitats in Michigan. It was the only non-native plant species commonly present in our site. Resource availability has been demonstrated to play a critical role in non-native plant invasion in multiple ecosystems (Davis et al. 2000; Borer et al. 2017). For example, cover and dominance of exotic grass species in desert environments increased with increased soil N (Brooks 2003; Barrows et al. 2009). Native species that are adapted to low-nutrient conditions may be outcompeted by more efficient non-native species when soil nutrient levels increase (Brooks 2003; Rickey and Anderson 2004). Such increases in non-native species can overwhelm changes in abiotic conditions (Craig and Henry 2022) and may further alter successional trajectories in the future (Marshall 2021). Managers should take care to prevent the establishment of more noxious non-native dune species such as Gypsophila paniculata, Leymus arenarius, or Centaurea stoebe in this site (Emery and Rudgers 2012; Emery et al. 2013; Reid and Emery 2017).
N and Epichloë effects on Ammophila growth
N addition had no consistent effect on the tiller density of Ammophila. Several studies report that fertilizer addition can increase Ammophila tiller number, both in incipient foredune populations and in declining populations (Augustine and Sharp 1969; Seliskar 1995; Boudreau and Houle 2001; Day et al. 2004, 2018), but we found significant N effects in only 1 year of our study (2018). In most study years, N had no significant effect on Ammophila density. It may be that Ammophila responses to N in our system depend on climate. The year 2018 had intermediate precipitation (904 mm; http://prism.oregonstate.edu). In wet years such as 2019 (1061 mm) and 2020 (973 mm), high rainfall may leach N quickly from plant rooting zones and thereby reduce the influence of N application, similar to what has been shown in some agricultural systems (Peng et al. 2011). In drier years such as 2016 (822 mm) and 2017 (886 mm), plants may be water stressed and unable to use additional N because water limitation dominates (He and Dijkstra 2014). More work is needed to understand how N deposition and climate change might interact to affect plant communities in the future (Komatsu et al. 2019; Kazanski et al. 2021).
Unlike N treatment effects which varied among years, Epichloë was associated with consistently increased Ammophila tiller density during the last 5 years of our long-term study, most likely as a carry-over of the initial benefits to Ammophila growth and survival provided during early years of the experiment (Emery et al. 2015). However, the rates of decline in tiller abundance during the past 5 years were similar across the two endophyte treatments, indicating that Epichloë provided little additional benefit to host plants during Ammophila die-off, in contrast to at least one other study of Epichloë effects on long-term host plant fitness and decline (Moore et al. 2019). Thus, we conclude that Epichloë is most important in early stages of host plant growth in this ecosystem where Epichloë plays a crucial role in earlier stages of succession by promoting tillering (Emery et al. 2015) before Ammophila die off begins.
Conclusion
To our knowledge, this is the first field study to assess the long-term effects of N addition and grass-endophyte symbiosis on early succession. Although Epichloë enhanced Ammophila tiller density over time, N addition did not strongly interact with Epichloë symbiosis to influence vegetative growth of Ammophila, which is notable given the limited number of short-term studies that have found N to increase benefits of fungal symbioses (Kivlin et al. 2013). Instead, N addition directly altered plant community composition by increasing the abundance of efficient colonizers, especially C4 grasses. N addition also suppressed the accumulation of plant diversity over time, though only when the endophyte was present in Ammophila. Our results suggest that early growth of ecosystem-engineering species may interact with N addition to affect later community succession. Additionally, high-value endemic species, such as C. pitcheri, may be particularly susceptible to N deposition in Great Lakes dune ecosystems.
Availability of data and material
The datasets used and/or analyzed during the current study are available from the corresponding author on reasonable request.
Code availability
The code used during the current study is available from the corresponding author on reasonable request.
References
Albert D (2000) Borne of the wind: an introduction to the ecology of Michigan Sand Dunes. Michigan Natural Feautures Inventory, Lansing
Anderson MJ (2006) Distance-based tests for homogeneity of multivariate dispersions. Biometrics 62:245–253
Barrows CW, Allen EB, Brooks ML, Allen MF (2009) Effects of an invasive plant on a desert sand dune landscape. Biol Invasions 11(3):673–686. https://doi.org/10.1007/s10530-008-9282-6
Barton K, Anderson DR (2015) Package ‘MuMIn’- Multi-model inference; model selection and model averaging based on information criteria (AICc and alike). Retrieved from https://cran.r-project.org/web/packages/MuMIn/MuMIn.pdf
Bell-Dereske L, Gao X, Masiello C, Sinsabaugh R, Emery S, Rudgers J (2017) Plant–fungal symbiosis affects litter decomposition during primary succession. Oikos 126:801–811
Bird EJ, Choi YD (2017) Response of native plants to elevated soil nitrogen in the sand dunes of Lake Michigan, USA. Biol Conserv 212:398–405. https://doi.org/10.1016/j.biocon.2016.12.001
Bobbink R, Hicks K, Galloway J, Spranger T, Alkemade R, Ashmore M et al (2010) Global assessment of nitrogen deposition effects on terrestrial plant diversity: a synthesis. Ecol Appl 20:30–59. https://doi.org/10.1890/08-1140.1
Borer ET, Harpole WS, Adler PB, Lind E, Orrock J, Seabloom E et al (2014) Finding generality in ecology: a model for globally distributed experiments. Methods Ecol Evol 5:65–73. https://doi.org/10.1111/2041-210X.12125
Borer ET, Grace JB, Harpole WS, MacDougall A, Seabloom E (2017) A decade of insights into grassland ecosystem responses to global environmental change. Nat Ecol Evol 1:118. https://doi.org/10.1038/s41559-017-0118
Boudreau S, Houle G (2001) The Ammophila decline: a field experiment on the effects of mineral nutrition. Ecoscience 8:392–398. https://doi.org/10.1080/11956860.2001.11682667
Brooks ML (2003) Effects of increased soil nitrogen on the dominance of alien annual plants in the Mojave Desert. J Appl Ecol 40:344–353. https://doi.org/10.1046/j.1365-2664.2003.00789.x
Burnham KP, Anderson DR (1998) Model selection and multimodel inference. Springer
Chalcraft DR, Cox SB, Clark C, Cleland E, Suding K, Weiher E et al (2008) Scale-dependent responses of plant biodiversity to nitrogen enrichment. Ecology 89:2165–2171. https://doi.org/10.1890/07-0971.1
Cheplick GP (2005) Patterns in the distribution of American beachgrass (Ammophila breviligulata) and the density and reproduction of annual plants on a coastal beach. Plant Ecol 180:57–67. https://doi.org/10.1007/s11258-005-2467-5
Christian JM, Wilson SD (1999) Long-term ecosystem impacts of an introduced grass in the northern great plains. Ecology 80:2397–2407. https://doi.org/10.2307/176919
Ciais P, Sabine C, Bala G, Bopp L, Brovkin V, Canadell J et al (2013) The physical science basis. Contribution of working group I to the fifth assessment report of the intergovernmental panel on climate change. Chang IPCC Clim. https://doi.org/10.1017/CBO9781107415324.015
Clark CM, Tilman D (2008) Loss of plant species after chronic low-level nitrogen deposition to prairie grasslands. Nature 451:712–715. https://doi.org/10.1038/nature06503
Clark CM, Cleland EE, Collins SL, Fargione J, Gough L, Gross K et al (2007) Environmental and plant community determinants of species loss following nitrogen enrichment. Ecol Lett 10:596–607. https://doi.org/10.1111/j.1461-0248.2007.01053.x
Clarke KR, Gorley RN (2009) Primer, version 6.1 10: user manual and tutorial. Prim Plymouth
Cleland E, Harpole W (2010) Nitrogen enrichment and plant communities. Ann N Y Acad Sci 1195:46–61. https://doi.org/10.1111/j.1749-6632.2010.05458.x
Cowles HC (1899) The ecological relations of the vegetation on the Sand Dunes of Lake Michigan. Part I. Geographical relations of the Dune Floras. Bot Gaz 27:95–117. https://doi.org/10.1086/327796
Craig BLH, Henry HAL (2022) Dominance by non-native grasses suppresses long-term shifts in plant species composition and productivity in response to global change. Oecologia 199:995–1005. https://doi.org/10.1007/s00442-022-05238-0
Crawley MJ, Johnston AE, Silvertown J, Dodd M, Mazancourt C, Heard MS et al (2005) Determinants of Species Richness in the Park Grass Experiment. Am Nat 165:179–192. https://doi.org/10.1086/427270
Crossett K, Culliton T, Wiley P, Goodspeed T (2004) Population trends along the coastal United States: 1980–2008. Coastal Trends Series Report, 1980–2008
David AS, Bell-Dereske LP, Emery SM, McCormic B, Seabloom E, Rudgers J (2019) Testing for loss of Epichloë and non-epichloid symbionts under altered rainfall regimes. Am J Bot 106:1081–1089. https://doi.org/10.1002/ajb2.1340
Davis MA, Grime JP, Thompson K (2000) Fluctuating resources in plant communities: a general theory of invasibility. J Ecol 88:528–534. https://doi.org/10.1046/j.1365-2745.2000.00473.x
Day FP, Conn C, Crawford E, Stevenson M (2004) Long-term effects of nitrogen fertilization on plant community structure on a coastal barrier island dune chronosequence. J Coast Res 20:722–730
Day FP, Adams EC, Gibala-Smith LA, Graziani D, McMillan B, Sedghi N et al (2018) Determining change in coastal barrier island dune vegetation following a decade of nitrogen fertilization. J Coast Res 34:1100–1104. https://doi.org/10.2112/JCOASTRES-D-17-00190.1
Drake I, White JF, Belanger FC (2018) Identification of the fungal endophyte of Ammophila breviligulata (American beachgrass) as Epichloë amarillans. PeerJ 2018:e4300. https://doi.org/10.7717/peerj.4300
Du E, de Vries W, Galloway JN, Hu X, Fang J (2014) Changes in wet nitrogen deposition in the United States between 1985 and 201. Environ Res Lett 9:095004. https://doi.org/10.1088/1748-9326/9/9/095004
Emery SM, Rudgers JA (2010) Ecological assessment of dune restorations in the Great Lakes region. Restor Ecol 18:184–194. https://doi.org/10.1111/j.1526-100X.2009.00609.x
Emery SM, Rudgers JA (2012) Impact of competition and mycorrhizal fungi on growth of centaurea stoebe, an invasive plant of sand dunes. Am Midl Nat 167:213–222. https://doi.org/10.1674/0003-0031-167.2.213
Emery SM, Rudgers JA (2014) Biotic and abiotic predictors of ecosystem engineering traits of the dune building grass, Ammophila breviligulata. Ecosphere 5:1–18. https://doi.org/10.1890/ES13-00331.1
Emery SM, Doran PJ, Legge JT, Kleitch M, Howard S (2013) Aboveground and belowground impacts following removal of the invasive species baby’s breath (Gypsophila paniculata) on Lake Michigan Sand Dunes. Restor Ecol 21:506–514. https://doi.org/10.1111/j.1526-100X.2012.00915.x
Emery SM, Bell-Dereske L, Rudgers JA (2015) Fungal symbiosis and precipitation alter traits and dune building by the ecosystem engineer, ammophila breviligulata. Ecology 96:927–935. https://doi.org/10.1890/14-1121.1
Foster BL, Gross KL (1998) Species richness in a successional grassland: effects of nitrogen enrichment and plant litter. Ecology 79:2593–2602. https://doi.org/10.2307/176503
Fowler D, Coyle M, Skiba U, Sutton M, Cape J, Reis S et al (2013) The global nitrogen cycle in the twenty-first century. Philos Trans R Soc B Biol Sci 368:20130164. https://doi.org/10.1098/rstb.2013.0164
Galloway JN, Townsend AR, Erisman JW, Bekunda M, Cai Z, Freney J et al (2008) Transformation of the nitrogen cycle: recent trends, questions, and potential solutions. Science (80-) 320:889–892. https://doi.org/10.1126/science.1136674
Garguillo MB, Gleason HA, Cronquist A (2004) Manual of vascular plants of northeastern United States and adjacent Canada. J Torrey Bot Soc 131:277. https://doi.org/10.2307/4126958
Gross KL, Mittelbach GG (2017) Negative effects of fertilization on grassland species richness are stronger when tall clonal species are present. Folia Geobot 52:401–409
Guo X, Liu H, Ngosong C, Li B, Wang Q, Zhou W et al (2022) Response of plant functional traits to nitrogen enrichment under climate change: a meta-analysis. Sci Total Environ 834:155379. https://doi.org/10.1016/j.scitotenv.2022.155379
Hager HA, Roloson JL, Shukla K, Yurkonis K, Newman J (2021) Effects of nutrient addition on endophyte-associated grass invasion in a long-term, old-field community experiment. Oecologia 196:469–482. https://doi.org/10.1007/s00442-021-04933-8
Harrison AM, Reisinger AJ, Cooper MJ, Brady V, Ciborowski J, O’Reilly K et al (2020) A basin-wide survey of coastal wetlands of the Laurentian Great Lakes: development and comparison of water quality indices. Wetlands 40:465–477. https://doi.org/10.1007/s13157-019-01198-z
Hastings A, Byers JE, Crooks JA, Cuddington K, Jones C, Lambrinos J et al (2007) Ecosystem engineering in space and time. Ecol Lett 10:153–164. https://doi.org/10.1111/j.1461-0248.2006.00997.x
He M, Dijkstra FA (2014) Drought effect on plant nitrogen and phosphorus: a meta-analysis. New Phytol 204:924–931. https://doi.org/10.1111/nph.12952
Hoeksema JD, Chaudhary VB, Gehring CA, Johnson NC, Justine K, Koide R et al (2010) A meta-analysis of context-dependency in plant response to inoculation with mycorrhizal fungi. Ecol Lett 13:394–407. https://doi.org/10.1111/j.1461-0248.2009.01430.x
Howarth RW (2008) Coastal nitrogen pollution: a review of sources and trends globally and regionally. Harmful Algae 8:14–20. https://doi.org/10.1016/j.hal.2008.08.015
Huberty LE, Gross KL, Miller CJ (1998) Effects of nitrogen addition on successional dynamics and species diversity in Michigan old-fields. J Ecol 86:794–803. https://doi.org/10.1046/j.1365-2745.1998.8650794.x
Humbert J-Y, Dwyer JM, Andrey A, Arlettaz R (2016) Impacts of nitrogen addition on plant biodiversity in mountain grasslands depend on dose, application duration and climate: a systematic review. Glob Chang Biol 22:110–120. https://doi.org/10.1111/gcb.12986
Inouye RS, Tilman D (1995) Convergence and divergence of old-field vegetation after 11 yr of nitrogen addition. Ecology 76:1872–1887. https://doi.org/10.2307/1940720
Johnson NC, Wilson GWT, Bowker MA, Wilson JA, Miller MR (2010) Resource limitation is a driver of local adaptation in mycorrhizal symbioses. Proc Natl Acad Sci USA 107:2093–2098. https://doi.org/10.1073/pnas.0906710107
Jones MLM, Wallace HL, Norris D, Brittain SA, Haria S, Jones RE et al (2004) Changes in vegetation and soil characteristics in coastal sand dunes along a gradient of atmospheric nitrogen deposition. Plant Biol 6:598–605. https://doi.org/10.1055/s-2004-821004
Kanakidou M, Myriokefalitakis S, Daskalakis N, Fanourgakis G, Nenes A, Baker AR et al (2016) Past, present, and future atmospheric nitrogen deposition. J Atmos Sci 73:2039–2047. https://doi.org/10.1175/JAS-D-15-0278.1
Kazanski CE, Cowles J, Dymond S, Clark AT, David AS, Jungers JM et al (2021) Water availability modifies productivity response to biodiversity and nitrogen in long-term grassland experiments. Ecol Appl 31:e02363. https://doi.org/10.1002/eap.2363
Kivlin SN, Emery SM, Rudgers JA (2013) Fungal symbionts alter plant responses to global change. Am J Bot 100:1445–1457. https://doi.org/10.3732/ajb.1200558
Komatsu KJ, Avolio ML, Lemoine NP, Isbell F, Grman E, Houseman GR et al (2019) Global change effects on plant communities are magnified by time and the number of global change factors imposed. Proc Natl Acad Sci 116:17867–17873. https://doi.org/10.1073/pnas.1819027116
Krauss J, Harri SA, Bush L, Husi R, Bigler L, Power SA et al (2007) Effects of fertilizer, fungal endophytes and plant cultivar on the performance of insect herbivores and their natural enemies. Funct Ecol 21:107–116. https://doi.org/10.1111/j.1365-2435.2006.01216.x
Lamarque JF, Dentener F, McConnell J, Ro CU, Shaw M, Vet R et al (2013) Multi-model mean nitrogen and sulfur deposition from the atmospheric chemistry and climate model intercomparison project (ACCMIP): Evaluation of historical and projected future changes. Atmos Chem Phys 13:7997–8018. https://doi.org/10.5194/acp-13-7997-2013
Lane G, Tapper B, Davies E, Hume D, Latch G, Barker D et al (1997) Effect of growth conditions on alkaloid concentrations in perennial ryegrass naturally infected with endophyte. Springer
Lefcheck JS (2016) piecewiseSEM: Piecewise structural equation modelling in r for ecology, evolution, and systematics. Methods Ecol Evol 7:573–579. https://doi.org/10.1111/2041-210X.12512
Lichter J (1998) Rates of weathering and chemical depletion in soils across a chronosequence of Lake Michigan sand dunes. Geoderma 85:255–282. https://doi.org/10.1016/S0016-7061(98)00026-3
Liu W, Liu L, Yang X, Deng M, Wang Z, Wang P et al (2021) Long-term nitrogen input alters plant and soil bacterial, but not fungal beta diversity in a semiarid grassland. Glob Chang Biol 27:3939–3950. https://doi.org/10.1111/gcb.15681
Malone TC, Newton A (2020) The globalization of cultural eutrophication in the coastal ocean: causes and consequences. Front Mar Sci 7:670
Marshall JM (2021) Spotted knapweed spread and plant community changes in a lacustrine dune system. Nat Areas J 41:11–17. https://doi.org/10.3375/043.041.0103
Maun MA, Lapierre J (1984) The effects of burial by sand on Ammophila breviligulata. J Ecol 72:827. https://doi.org/10.2307/2259534
Midolo G, Alkemade R, Schipper AM, Benitez-Lopez A, Perring MP, De Vries W et al (2019) Impacts of nitrogen addition on plant species richness and abundance: a global meta-analysis. Glob Ecol Biogeogr 28:398–413. https://doi.org/10.1111/geb.12856
Moore JD, Carlisle AE, Nelson JA, McCulley RL (2019) Fungal endophyte infection increases tall fescue’s survival, growth, and flowering in a reconstructed prairie. Restor Ecol 27:1000–1007. https://doi.org/10.1111/rec.12960
Morrice JA, Danz NP, Regal RR, Kelly JR, Niemi GJ, Reavie ED et al (2008) Human influences on water quality in Great Lakes coastal wetlands. Environ Manage 41:347–357. https://doi.org/10.1007/s00267-007-9055-5
National Atmospheric Deposition Program (2022) NRSP-3. National Atmospheric Deposition Program
Olson JS (1958) Rates of succession and soil changes on southern Lake Michigan Sand Dunes. Bot Gaz 119:125–170. https://doi.org/10.1086/335973
Pavlovic NB, Bowles ML, Crispin SR, Gibson TC, Herman KD, Kavetsky RT et al (1998) Pitcher’s thistle (Cirsium pitcheri) recovery plan. Report prepared for US Fish and Wildlife, Minneapolis, MN
Payne RJ, Dise NB, Field CD, Dore AJ, Caporn SJM, Stevens CJ (2017) Nitrogen deposition and plant biodiversity: past, present, and future. Front Ecol Environ 15:431–436. https://doi.org/10.1002/fee.1528
Peng SZ, Yang SH, Xu JZ, Luo YF, Hou HJ (2011) Nitrogen and phosphorus leaching losses from paddy fields with different water and nitrogen managements. Paddy Water Environ 9:333–342. https://doi.org/10.1007/s10333-010-0246-y
Pinheiro J, Bates D, DebRoy S, Sarkar D, Heisterkamp S, Van Willigen B (2017) nlme: linear and nonlinear mixed effects models. CRAN
PRISM (2012) PRISM. https://prism.oregonstate.edu
Reid ML, Emery SM (2017) Native and exotic foundation grasses differ in traits and responses to belowground tri-trophic interactions. Plant Ecol 218:173–183. https://doi.org/10.1007/s11258-016-0675-9
Rickey MA, Anderson RC (2004) Effects of nitrogen addition on the invasive grass Phragmites australis and a native competitor Spartina pectinata. J Appl Ecol 41:888–896. https://doi.org/10.1111/j.0021-8901.2004.00948.x
Rowland J, Maun MA (2001) Restoration ecology of an endangered plant species: establishment of new populations of Cirsium pitcheri. Restor Ecol 9:60–70. https://doi.org/10.1046/j.1526-100x.2001.009001060.x
Rudgers JA, Afkhami ME, Rúa MA, Davit AJ, Hammer S, Huguet VM (2009) A fungus among us: Broad patterns of endophyte distribution in the grasses. Ecology 90:1531–1539. https://doi.org/10.1890/08-0116.1
Rudgers JA, Bell-Dereske L, Crawford KM, Emery SM (2015) Fungal symbiont effects on dune plant diversity depend on precipitation. J Ecol 103:219–230. https://doi.org/10.1111/1365-2745.12338
Seabloom EW, Adler PB, Alberti J, Biederman L, Buckley YM, Cadotte MW et al (2021) Increasing effects of chronic nutrient enrichment on plant diversity loss and ecosystem productivity over time. Ecology 102:e03218. https://doi.org/10.1002/ecy.3218
Seliskar DM (1995) Coastal dune restoration: a strategy for alleviating dieout of Ammophila breviligulata. Restor Ecol 3:54–60. https://doi.org/10.1111/j.1526-100X.1995.tb00075.x
Sparrius LB, Sevink J, Kooijman AM (2012) Effects of nitrogen deposition on soil and vegetation in primary succession stages in inland drift sands. Plant Soil 353:261–272. https://doi.org/10.1007/s11104-011-1029-y
Staehlin B, Fant J (2015) Climate change impacts on seedling establishment for a threatened endemic thistle, Cirsium pitcheri. Am Midl Nat. https://doi.org/10.1674/0003-0031-173.1.47
Stevens CJ, Dise NB, Mountford JO, Gowing DJ (2004) Impact of nitrogen deposition on the species richness of grasslands. Science (80-) 303:1876–1879. https://doi.org/10.1126/science.1094678
Su J, Zhao Y, Xu F, Bai Y (2022) Multiple global changes drive grassland productivity and stability: a meta-analysis. J Ecol. https://doi.org/10.1111/1365-2745.13983
Suding KN, Collins SL, Gough L, Clark C, Cleland EE, Gross KL et al (2005) Functional- and abundance-based mechanisms explain diversity loss due to N fertilization. Proc Natl Acad Sci USA 102:4387–4392. https://doi.org/10.1073/pnas.0408648102
Tilman D (1987) Secondary succession and the pattern of plant dominance along experimental nitrogen gradients. Ecol Monogr 57:189–214. https://doi.org/10.2307/2937080
Titus JH (2009) Nitrogen-fixers Alnus and Lupinus influence soil characteristics but not colonization by later successional species in primary succession on Mount St. Helens Plant Ecol 203:289–301. https://doi.org/10.1007/s11258-008-9549-0
Vitousek PM, Aber JD, Howarth RW, Likens GE, Matson PA, Schindler DW et al (1997) Human alteration of the global nitrogen cycle: sources and consequences. Ecol Appl 7:737–750. https://doi.org/10.2307/2269431
Voesenek LACJ, Van Der Putten WH, Maun MA, Blom CWPM (1998) The role of ethylene and darkness in accelerated shoot elongation of Ammophila breviligulata upon sand burial. Oecologia 115:359–365. https://doi.org/10.1007/s004420050528
Weese DJ, Heath KD, Dentinger BTM, Lau JA (2015) Long-term nitrogen addition causes the evolution of less-cooperative mutualists. Evolution (NY) 69:631–642. https://doi.org/10.1111/evo.12594
Wipf D, Krajinski F, van Tuinen D, Recorbet G, Courty PE (2019) Trading on the arbuscular mycorrhiza market: from arbuscules to common mycorrhizal networks. New Phytol 223:1127–1142. https://doi.org/10.1111/nph.15775
Xia J, Wan S (2008) Global response patterns of terrestrial plant species to nitrogen addition. New Phytol 179:428–439. https://doi.org/10.1111/j.1469-8137.2008.02488.x
You C, Wu F, Gan Y, Yang W, Hu Z, Xu Z et al (2017) Grass and forbs respond differently to nitrogen addition: a meta-analysis of global grassland ecosystems. Sci Rep. https://doi.org/10.1038/s41598-017-01728-x
Zarnetske PL, Skelly DK, Urban MC (2012) Biotic multipliers of climate change. Science 80(336):1516–1518. https://doi.org/10.1126/science.1222732
Zhang Y, Feng J, Loreau M, He N, Han X, Jiang L (2019) Nitrogen addition does not reduce the role of spatial asynchrony in stabilising grassland communities. Ecol Lett 22:563–571. https://doi.org/10.1111/ele.13212
Zhou X, Liu X, Zhang P, Guo Z, Du G (2019) Increased community compositional dissimilarity alleviates species loss following nutrient enrichment at large spatial scales. J Plant Ecol 12:376–386. https://doi.org/10.1093/jpe/rty035
Acknowledgements
We thank Brad Kimbrough, Susanne Cramer, Josh Cramer, Aaron Sexton, Grace Freundlich, Kimberly Koenig, Katie Marx, Jessica Raley, Matthew Reid and Sarah Reid for field assistance.
Funding
This work has been funded by an NSF Graduate Research Fellowship to KRG, and the original field experiment was funded by NSF#0918267 to JAR and SME and a National Parks Ecological Research Post-Doctoral Fellowship to SME.
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KRG and SME conducted the experiment, collected, and analyzed data, and wrote the manuscript. JAR assisted with experiment design, data analysis, and manuscript preparation. LBD helped with experiment maintenance, data collection, and manuscript edits.
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Communicated by Melinda D. Smith.
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Garces, K.R., Bell-Dereske, L., Rudgers, J.A. et al. Nitrogen addition and fungal symbiosis alter early dune plant succession. Oecologia 201, 1067–1077 (2023). https://doi.org/10.1007/s00442-023-05362-5
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DOI: https://doi.org/10.1007/s00442-023-05362-5