@article {KNZ001787,
	title = {Integrative modelling reveals mechanisms linking productivity and plant species richness},
	journal = {Nature},
	volume = {529},
	year = {2016},
	pages = {390 - 393},
	abstract = {<p>How ecosystem productivity and species richness are interrelated is one of the most debated subjects in the history of ecology1. Decades of intensive study have yet to discern the actual mechanisms behind observed global patterns2, 3. Here, by integrating the predictions from multiple theories into a single model and using data from 1,126 grassland plots spanning five continents, we detect the clear signals of numerous underlying mechanisms linking productivity and richness. We find that an integrative model has substantially higher explanatory power than traditional bivariate analyses. In addition, the specific results unveil several surprising findings that conflict with classical models4, 5, 6, 7. These include the isolation of a strong and consistent enhancement of productivity by richness, an effect in striking contrast with superficial data patterns. Also revealed is a consistent importance of competition across the full range of productivity values, in direct conflict with some (but not all) proposed models. The promotion of local richness by macroecological gradients in climatic favourability, generally seen as a competing hypothesis8, is also found to be important in our analysis. The results demonstrate that an integrative modelling approach leads to a major advance in our ability to discern the underlying processes operating in ecological systems.</p>},
	keywords = {LTER-KNZ},
	doi = {10.1038/nature16524},
	url = {https://www.nature.com/articles/nature16524},
	author = {Grace, J.B. and Anderson, T.M. and Seabloom, E.W. and E.T. Borer and P. Adler and Harpole, W.S. and Hautier, Y. and Hillebrand, H. and Lind, E.M. and P{\"a}rtel, M. and J.D. Bakker and Buckley, Y.M. and Crawley, M.J. and Damschen, E.I. and Davies, K.F. and Fay, P.A. and Firn, J. and Gruner, D.S. and Hector, A. and Knops, J.M.H. and MacDougall, A.S. and Melbourne, B.A. and J.W. Morgan and Orrock, J.L. and Prober, S.M. and M.D. Smith}
}
@article {KNZ001448,
	title = {Productivity is a poor predictor of plant species richness},
	journal = {Science},
	volume = {333},
	year = {2011},
	pages = {1750 -1753},
	abstract = {<p>For more than 30 years, the relationship between net primary productivity and species richness has generated intense debate in ecology about the processes regulating local diversity. The original view, which is still widely accepted, holds that the relationship is hump-shaped, with richness first rising and then declining with increasing productivity. Although recent meta-analyses questioned the generality of hump-shaped patterns, these syntheses have been criticized for failing to account for methodological differences among studies. We addressed such concerns by conducting standardized sampling in 48 herbaceous-dominated plant communities on five continents. We found no clear relationship between productivity and fine-scale (meters\&minus;2) richness within sites, within regions, or across the globe. Ecologists should focus on fresh, mechanistic approaches to understanding the multivariate links between productivity and richness.</p>},
	keywords = {LTER-KNZ},
	doi = {10.1126/science.1204498},
	url = {http://science.sciencemag.org/content/333/6050/1750},
	author = {P. Adler and Seabloom, E.W. and E.T. Borer and Hillebrand, H. and Hautier, Y. and Hector, A. and Harpole, W.S. and O{\textquoteright}Halloran, L.R. and Grace, J.B. and Anderson, T.M. and J.D. Bakker and L.A. Biederman and C.S. Brown and Buckley, Y.M. and Calabrese, L.B. and Chu, C.J. and Cleland, E.E. and Scott. L. Collins and Cottingham, K.L. and Crawley, M.J. and Damschen, E.I. and Davies, K.F. and DeCrappeo, N.M. and Fay, P.A. and Firn, J. and Frater, P. and Gasarch, E.I. and Gruner, D.S. and Hagenah, N. and HilleRisLambers, J. and Humphries, H.C. and Jin, V.L. and Kay, A. and Kirkman, K.P. and Klein, J.A. and Knops, J.M.H. and Kimberly J. La Pierre and Lambrinos, J.G. and Li, W. and MacDougall, A.S. and McCulley, R.L. and Melbourne, B.A. and Mitchell, C.E. and Joslin L. Moore}
}
@article {KNZ001172,
	title = {Does species diversity limitproductivity in natural grassland communities?},
	journal = {Ecology Letters},
	volume = {10},
	year = {2007},
	pages = {680 -689},
	abstract = {Theoretical analyses and experimental studies of synthesized assemblages indicate that under particular circumstances species diversity can enhance community productivity through niche complementarity. It remains unclear whether this process has important effects in mature natural ecosystems where competitive feedbacks and complex environmental influences affect diversity{\textendash}productivity relationships. In this study, we evaluated diversity{\textendash}productivity relationships while statistically controlling for environmental influences in 12 natural grassland ecosystems. Because diversity{\textendash}productivity relationships are conspicuously nonlinear, we developed a nonlinear structural equation modeling (SEM) methodology to separate the effects of diversity on productivity from the effects of productivity on diversity. Meta-analysis was used to summarize the SEM findings across studies. While competitive effects were readily detected, enhancement of production by diversity was not. These results suggest that the influence of small-scale diversity on productivity in mature natural systems is a weak force, both in absolute terms and relative to the effects of other controls on productivity.},
	keywords = {LTER-KNZ},
	doi = {10.1111/j.1461-0248.2007.01058.x},
	author = {Grace, J.B. and Anderson, T.M. and M.D. Smith and Seabloom, E. and Andelman, S.J. and Meche, G. and Weiher, E. and Allain, L.K. and Jutila, H. and Sankaran, M. and Knops, J. and Ritchie, M. and M.R. Whiles}
}
@article {KNZ001094,
	title = {Environmental and plant community determinants ofspecies loss following nitrogen enrichment},
	journal = {Ecology Letters},
	volume = {10},
	year = {2007},
	pages = {596 -607},
	abstract = {Global energy use and food production have increased nitrogen inputs to ecosystems worldwide, impacting plant community diversity, composition, and function. Previous studies show considerable variation across terrestrial herbaceous ecosystems in the magnitude of species loss following nitrogen (N) enrichment. What controls this variation remains unknown. We present results from 23 N-addition experiments across North America, representing a range of climatic, soil and plant community properties, to determine conditions that lead to greater diversity decline. Species loss in these communities ranged from 0 to 65\% of control richness. Using hierarchical structural equation modelling, we found greater species loss in communities with a lower soil cation exchange capacity, colder regional temperature, and larger production increase following N addition, independent of initial species richness, plant productivity, and the relative abundance of most plant functional groups. Our results indicate sensitivity to N addition is co-determined by environmental conditions and production responsiveness, which overwhelm the effects of initial community structure and composition.},
	keywords = {LTER-KNZ},
	doi = {10.1111/j.1461-0248.2007.01053.x},
	author = {Clark, C.M. and Cleland, E.E. and Scott. L. Collins and Fargione, J.E. and Gough, L. and Pennings, S.C. and K.N. Suding and Grace, J.B.}
}
@proceedings {KNZ007,
	title = {Interactions between fire and invasive plants in temperate grasslands of North America},
	year = {2001},
	pages = {40 -65},
	publisher = {Tall Timbers Research Station},
	address = {Tallahassee, FL},
	abstract = {A substantial number of invasive grasses, forbs and woody plants have invaded temperate grasslands in North America. Among the invading species are winter annuals, biennials, cool-season perennials, warm-season perennials, vines, shrubs, and trees. Many of these species have been deliberately introduced and widely planted; some are still used for range improvement, pastures, lawns, and as ornamentals, though many are listed as state or federal noxious weeds. Others have been greatly facilitated by widespread land disturbance. Historically, fire has been a major selective force in the evolution of temperate grasslands. Further, prescribed fire is commonly used as a method of ecological management for native grassland communities as well as in conjunction with restoration efforts. Within this context, it is important to understand how invasive species will interact with natural and prescribed fire regimes. In this paper, we consider what is known about how exotic species that invade temperate grasslands relate to fire. The primary issues addressed for each species are (1) Does fire appear to enhance colonization? (2) To what degree does fire affect the survival of plants? (3) Are plants that are burned able to regrow following fire and, if so, how rapidly can they recover? (4) How important is competition with native species to the response to fire? and (5) What effect does an invasive species have on the characteristics of the fire regime? For many species, results are preliminary, incomplete, or inconsistent among studies. For this reason, many of the conclusions drawn for individual species must be considered preliminary. Based on analyses of individual species, a conceptual framework is presented for considering how invasive plants may interact with fire when they invade an ecosystem. The major categories of influences are the native community, the fire regime, growth conditions for both invasive and native species, and influences that disturbances, human impacts, and landscape characteristics have had in the past and will have in the future. The examples considered in this paper provide support for a few, tentative generalizations. First, among our current worst invaders of temperate grasslands, adaptation to fire is quite variable. Some species are not well adapted to burning and can be easily eliminated; other species are better adapted but can still be eliminated if fire occurs during periods of particular vulnerability and/or at high frequency. There is a set of species that is extremely well adapted to fire and will not be eliminated through burning alone. Second, competitive interactions with native species play a crucial role in the success of nonnative invaders. In cases where differential burn responses between invasive and native species can be exploited, and adequate populations of native dominant species are present, fire can sometimes tip the competitive balance away from invasives. Third, there are a few invasive species that have exceptional attributes and for which there are no easy solutions. The ability of cheatgrass (Bromus tectorum) to enhance fire, the ability of Chinese tallow (Triadica sebifera) to suppress fire, and the ability of leafy spurge (Euphorbia esula) to resprout from repeated injury make the sespecies exceptional threats to native diversity. Finally, the available information for many invasive species is very incomplete, particularly with regard to how fire affects competitive interactions with the native community. There is much more we need to know if we are to consistently predict how invasive species will respond to fire and how burning can best be used to manage for natural diversity},
	keywords = {LTER-KNZ, alien plants, exotic species, fire, Grasslands, invasive plants, prairie},
	author = {Grace, J.B. and M.D. Smith and Grace, S.L. and Scott. L. Collins and Stohlgren, T.J.},
	editor = {Galley, K. and Wilson, T.}
}
