@article {KNZ002036,
	title = {Temporal variability in production is not consistently affected by global change drivers across herbaceous-dominated ecosystems},
	journal = {Oecologia},
	volume = {194},
	year = {2020},
	pages = {735{\textendash}744},
	keywords = {LTER-KNZ},
	doi = {10.1007/s00442-020-04787-6},
	url = {https://link.springer.com/article/10.1007/s00442-020-04787-6},
	author = {Avolio, M.L. and Wilcox, K.R. and La Pierre, K.J. and Lemoine, N. and Bowman, W.D. and Collins, S.L. and Knapp, A.K. and Koerner, S.E. and Smith, M.D. and Baer, S.G. and Gross, K.L. and Isbell, F. and McLaren, J. and Reich, P.B. and Suding, K.N. and Suttle, K.B. and Tilman, D. and Xu, Z. and Yu, Q.}
}
@article {KNZ001898,
	title = {Ambient changes exceed treatment effects on plant species abundance in long-term global change experiments},
	journal = {Glob Chang Biol},
	volume = {24},
	year = {2018},
	pages = {5668 - 5679},
	abstract = {<p>The responses of species to environmental changes will determine future community composition and ecosystem function. Many syntheses of global change experiments examine the magnitude of treatment effect sizes, but we lack an understanding of how plant responses to treatments compare to ongoing changes in the unmanipulated (ambient or background) system. We used a database of long-term global change studies manipulating CO2 , nutrients, water, and temperature to answer three questions: (a) How do changes in plant species abundance in ambient plots relate to those in treated plots? (b) How does the magnitude of ambient change in species-level abundance over time relate to responsiveness to global change treatments? (c) Does the direction of species-level responses to global change treatments differ from the direction of ambient change? We estimated temporal trends in plant abundance for 791 plant species in ambient and treated plots across 16 long-term global change experiments yielding 2,116 experiment-species-treatment combinations. Surprisingly, for most species (57\%) the magnitude of ambient change was greater than the magnitude of treatment effects. However, the direction of ambient change, whether a species was increasing or decreasing in abundance under ambient conditions, had no bearing on the direction of treatment effects. Although ambient communities are inherently dynamic, there is now widespread evidence that anthropogenic drivers are directionally altering plant communities in many ecosystems. Thus, global change treatment effects must be interpreted in the context of plant species trajectories that are likely driven by ongoing environmental changes.</p>},
	keywords = {LTER-KNZ, elevated CO2, nitrogen, Phosphorus, plant community, Warming, water},
	doi = {10.1111/gcb.14442},
	url = {https://onlinelibrary.wiley.com/doi/abs/10.1111/gcb.14442},
	author = {Langley, A. and Chapman, S.K. and Kimberly J. La Pierre and M.L. Avolio and W.D. Bowman and Johnson, D. and Isbell, F. and K.R. Wilcox and Foster, B. and Hovenden, M. and Alan K. Knapp and Koerner, S.E. and Lortie, C. and Megonigal, J. and Newton, P. and Reich, B. and M.D. Smith and Suttle, B.K. and Tilman, D.}
}
@article {KNZ001180,
	title = {Species responses to nitrogen fertilization in herbaceous plant communities, and associated species traits},
	journal = {Ecology},
	volume = {89},
	year = {2008},
	pages = {1175 -},
	abstract = {<p>This synthetic data set contains plant species relative abundance measures from 35 nitrogen (N) fertilization experiments conducted at 10 sites across North America. The data set encompasses the fertilization responses of 575 taxa from 1159 experimental plots. The methodology varied among experiments, in particular with regard to the type and amount of N added, plot size, species composition measure (biomass harvest, pin count, or percent cover), additional experimental manipulations, and experimental duration. At each site, each species has been classified according to a number of easily identified categorical functional traits, including life history, life form, the number of cotyledons, height relative to the canopy, potential for clonal growth, and nativity to the United States. Additional data are available for many sites, indicated by references to publications and web sites. Analyses of these data have shown that N enrichment significantly alters community composition in ways that are predictable on the basis of plant functional traits as well as environmental context. This data set could be used to answer a variety of questions about how plant community composition and structure respond to environmental changes.</p>},
	keywords = {LTER-KNZ},
	doi = {10.1890/07-1104.1},
	url = {https://esajournals.onlinelibrary.wiley.com/doi/full/10.1890/07-1104.1},
	author = {Cleland, E.E. and Clark, C.M. and Scott. L. Collins and Fargione, J.E. and Gough, L. and Gross, K.L. and Pennings, S.C. and W.D. Bowman and Robertson, G.P. and Simpson, J. and Tilman, D. and K.N. Suding}
}
@article {KNZ001048,
	title = {Non-neutral patterns of species abundance in grassland communities},
	journal = {Ecology Letters},
	volume = {9},
	year = {2006},
	pages = {15 -23},
	abstract = {Although the distribution of plant species abundance in a Minnesota grassland was consistent with neutral theory, niche but not neutral mechanisms were supported by the ability of species traits to predict species abundances in three experimental grassland communities. In particular, data from 27 species grown in monoculture showed that species differed in a trait, R*, which is the level to which each species reduced the concentration of soil nitrate, the limiting soil nutrient and which is predicted to be inversely associated with competitive ability for nitrogen (N). In these N-limited habitats, species abundance ranks correlated with their predicted competitive ranks: low R* species, on average dominated. These correlations were significantly different than expected for neutral theory, which assumes the exchangeability of species traits. Additionally, we found that changes in relative abundance after environmental change (N-addition or disturbance) were not neutral but also were significantly associated with R*.},
	keywords = {LTER-KNZ},
	doi = {10.1111/j.1461-0248.2005.00836.x},
	author = {Harpole, W.S. and Tilman, D.}
}
@article {KNZ00845,
	title = {The importance of land-use legacies to ecology and conservation},
	journal = {BioScience},
	volume = {53},
	year = {2003},
	pages = {77 -88},
	abstract = {Recognition of the importance of land-use history and its legacies in most ecological systems has been a major factor driving the recent focus on human activity as a legitimate and essential subject of environmental science. Ecologists, conservationists, and natural resource policymakers now recognize that the legacies of land-use activities continue to influence ecosystem structure and function for decades or centuries{\textemdash}or even longer{\textemdash}after those activities have ceased. Consequently, recognition of these historical legacies adds explanatory power to our understanding of modern conditions at scales from organisms to the globe and reduces missteps in anticipating or managing for future conditions. As a result, environmental history emerges as an integral part of ecological science and conservation planning. By considering diverse ecological phenomena, ranging from biodiversity and biogeochemical cycles to ecosystem resilience to anthropogenic stress, and by examining terrestrial and aquatic ecosystems in temperate to tropical biomes, this article demonstrates the ubiquity and importance of land-use legacies to environmental science and management.},
	keywords = {LTER-KNZ, conservation, disturbance, ecosystem process, Land use, natural resource management},
	doi = {10.1641/0006-3568(2003)053[0077:TIOLUL]2.0.CO;2},
	author = {D.R. Foster and Swanson, F. and Aber, J. and I. Burke and Brokaw, N. and Tilman, D. and Alan K. Knapp}
}
@article {KNZ00472,
	title = {Plant production and the biomass of soil microorganisms in late-successional ecosystems: A continental-scale study},
	journal = {Ecology},
	volume = {75},
	year = {1994},
	pages = {2333 -2347},
	abstract = {Annual C inputs from plant production in terrestrial ecosystems only meet the maintenance energy requirements of soil microorganisms, allowing for little or no net annual increase in their biomass. Because microbial growth within soil is limited by C availability, we reasoned that plant production should, in part, control the biomass of soil microorganisms. We also reasoned that soil texture should further modify the influence of plant production on soil C availability because fine-textured soils typically support more microbial biomass than coarse-textured soils. To test these ideas, we quantified the relationship between aboveground net primary production (ANPP) and soil microbial biomass in late-successional ecosystems distributed along a continent-wide gradient in North America. We also measured labile pools of C and N within the soil because they represent potential substrate for microbial activity. Ecosystems ranged from a Douglas-fir forest in the western United States to the grasslands of the mid-continent to the hardwood forest in the eastern U.S. Estimates of ANPP obtained from the literature ranged from 82 to 1460 g@?m^-^2@?yr^-^1. Microbial biomass C and N were estimated by the fumigation-incubation technique. Labile soil pools of C and N and first-order rate constants for microbial respiration and net N mineralization were estimated using a long-term (32 wk) laboratory incubation. Regression analyses were used to relate ANPP and soil texture with microbial biomass and labile soil C and N pools. Microbial biomass carbon ranged from 2 g/m^2 in the desert grassland to 134 g/m^2 in the tallgrass prairie; microbial N displayed a similar trend among ecosystems. Labile C pools, derived from a first-order rate equation, ranged from 115 g/m^2 in the desert grassland to 491 g/m^2 in the southern hardwood forest. First-order rate constants for microbial respiration (k) fell within a narrow range of values (0.180 to 0.357 wk^-^1), suggesting that labile C pools were chemically similar among this diverse set of ecosystems. Potential net N mineralization rates over the 32-wk incubation were linear in most ecosystems with first-order responses only in the alpine tundra, tallgrass prairie, and forests. Microbial biomass C displayed a positive, linear relationship with ANPP (r^2 = 0.51), but was not significantly related to soil texture. Labile C also was linearly related to ANPP (r^2 = 0.32) and to soil texture (r^2 = 0.33). Results indicate that microbial biomass and labile organic matter pools change predictably across broad gradients of ANPP, supporting the idea that microbial growth in soil is constrained by C availability.},
	keywords = {LTER-KNZ},
	doi = {10.2307/1940888},
	author = {Zak, D.R. and Tilman, D. and Parameter, R.R. and Fisher, F.M. and C. W. Rice and Vose, J. and Milchunas, D. and Martin, C.W.}
}
