Search

Your search keyword '"Yahdjian, L. (Laura)"' showing total 5 results
Start Over Author "Yahdjian, L. (Laura)"
5 results on '"Yahdjian, L. (Laura)"'

1. Evolutionary history of grazing and resources determine herbivore exclusion effects on plant diversity

Author

Price, J. N. (Jodi N.), Sitters, J. (Judith), Ohlert, T. (Timothy), Tognetti, P. M. (Pedro M.), Brown, C. S. (Cynthia S.), Seabloom, E. W. (Eric W.), Borer, E. T. (Elizabeth T.), Prober, S. M. (Suzanne M.), Bakker, E. S. (Elisabeth S.), MacDougall, A. S. (Andrew S.), Yahdjian, L. (Laura), Gruner, D. S. (Daniel S.), Olde Venterink, H. (Harry), Barrio, I. C. (Isabel C.), Graff, P. (Pamela), Bagchi, S. (Sumanta), Arnillas, C. A. (Carlos Alberto), Bakker, J. D. (Jonathan D.), Blumenthal, D. M. (Dana M.), Boughton, E. H. (Elizabeth H.), Brudvig, L. A. (Lars A.), Bugalho, M. N. (Miguel N.), Cadotte, M. W. (Marc W.), Caldeira, M. C. (Maria C.), Dickman, C. R. (Chris R.), Donohue, I. (Ian), Grégory, S. (Sonnier), Hautier, Y. (Yann), Jónsdóttir, I. S. (Ingibjörg S.), Lannes, L. S. (Luciola S.), McCulley, R. L. (Rebecca L.), Moore, J. L. (Joslin L.), Power, S. A. (Sally A.), Risch, A. C. (Anita C.), Schütz, M. (Martin), Standish, R. (Rachel), Stevens, C. J. (Carly J.), Veen, G. F. (G. F.), Virtanen, R. (Risto), Wardle, G. M. (Glenda M.), Price, J. N. (Jodi N.), Sitters, J. (Judith), Ohlert, T. (Timothy), Tognetti, P. M. (Pedro M.), Brown, C. S. (Cynthia S.), Seabloom, E. W. (Eric W.), Borer, E. T. (Elizabeth T.), Prober, S. M. (Suzanne M.), Bakker, E. S. (Elisabeth S.), MacDougall, A. S. (Andrew S.), Yahdjian, L. (Laura), Gruner, D. S. (Daniel S.), Olde Venterink, H. (Harry), Barrio, I. C. (Isabel C.), Graff, P. (Pamela), Bagchi, S. (Sumanta), Arnillas, C. A. (Carlos Alberto), Bakker, J. D. (Jonathan D.), Blumenthal, D. M. (Dana M.), Boughton, E. H. (Elizabeth H.), Brudvig, L. A. (Lars A.), Bugalho, M. N. (Miguel N.), Cadotte, M. W. (Marc W.), Caldeira, M. C. (Maria C.), Dickman, C. R. (Chris R.), Donohue, I. (Ian), Grégory, S. (Sonnier), Hautier, Y. (Yann), Jónsdóttir, I. S. (Ingibjörg S.), Lannes, L. S. (Luciola S.), McCulley, R. L. (Rebecca L.), Moore, J. L. (Joslin L.), Power, S. A. (Sally A.), Risch, A. C. (Anita C.), Schütz, M. (Martin), Standish, R. (Rachel), Stevens, C. J. (Carly J.), Veen, G. F. (G. F.), Virtanen, R. (Risto), and Wardle, G. M. (Glenda M.)

Abstract

Ecological models predict that the effects of mammalian herbivore exclusion on plant diversity depend on resource availability and plant exposure to ungulate grazing over evolutionary time. Using an experiment replicated in 57 grasslands on six continents, with contrasting evolutionary history of grazing, we tested how resources (mean annual precipitation and soil nutrients) determine herbivore exclusion effects on plant diversity, richness and evenness. Here we show that at sites with a long history of ungulate grazing, herbivore exclusion reduced plant diversity by reducing both richness and evenness and the responses of richness and diversity to herbivore exclusion decreased with mean annual precipitation. At sites with a short history of grazing, the effects of herbivore exclusion were not related to precipitation but differed for native and exotic plant richness. Thus, plant species’ evolutionary history of grazing continues to shape the response of the world’s grasslands to changing mammalian herbivory.

Published
2022

2. Long-term N-addition alters the community structure of functionally important N-cycling soil microorganisms across global grasslands

Author

Frey, B. (Beat), Moser, B. (Barbara), Tytgat, B. (Bjorn), Zimmermann, S. (Stephan), Alberti, J. (Juan), Biederman, L. A. (Lori A.), Borer, E. T. (Elizabeth T.), Broadbent, A. A. (Arthur A. D.), Caldeira, M. C. (Maria C.), Davies, K. F. (Kendi F.), Eisenhauer, N. (Nico), Eskelinen, A. (Anu), Fay, P. A. (Philip A.), Hagedorn, F. (Frank), Hautier, Y. (Yann), MacDougall, A. S. (Andrew S.), McCulley, R. L. (Rebecca L.), Moore, J. L. (Joslin L.), Nepel, M. (Maximilian), Power, S. A. (Sally A.), Seabloom, E. W. (Eric W.), Vázquez, E. (Eduardo), Virtanen, R. (Risto), Yahdjian, L. (Laura), Risch, A. C. (Anita C.), Frey, B. (Beat), Moser, B. (Barbara), Tytgat, B. (Bjorn), Zimmermann, S. (Stephan), Alberti, J. (Juan), Biederman, L. A. (Lori A.), Borer, E. T. (Elizabeth T.), Broadbent, A. A. (Arthur A. D.), Caldeira, M. C. (Maria C.), Davies, K. F. (Kendi F.), Eisenhauer, N. (Nico), Eskelinen, A. (Anu), Fay, P. A. (Philip A.), Hagedorn, F. (Frank), Hautier, Y. (Yann), MacDougall, A. S. (Andrew S.), McCulley, R. L. (Rebecca L.), Moore, J. L. (Joslin L.), Nepel, M. (Maximilian), Power, S. A. (Sally A.), Seabloom, E. W. (Eric W.), Vázquez, E. (Eduardo), Virtanen, R. (Risto), Yahdjian, L. (Laura), and Risch, A. C. (Anita C.)

Abstract

Anthropogenic nitrogen (N) input is known to alter the soil microbiome, but how N enrichment influences the abundance, alpha-diversity and community structure of N-cycling functional microbial communities in grasslands remains poorly understood. Here, we collected soils from plant communities subjected to up to 9 years of annual N-addition (10 g N m⁻² per year using urea as a N-source) and from unfertilized plots (control) in 30 grasslands worldwide spanning a large range of climatic and soil conditions. We focused on three key microbial groups responsible for two essential processes of the global N cycle: N₂ fixation (soil diazotrophs) and nitrification (AOA: ammonia-oxidizing archaea and AOB: ammonia-oxidizing bacteria). We targeted soil diazotrophs, AOA and AOB using Illumina MiSeq sequencing and measured the abundance (gene copy numbers) using quantitative PCR. N-addition shifted the structure of the diazotrophic communities, although their alpha-diversity and abundance were not affected. AOA and AOB responded differently to N-addition. The abundance and alpha-diversity of AOB increased, and their community structure shifted with N-addition. In contrast, AOA were not affected by N-addition. AOA abundance outnumbered AOB in control plots under conditions of low N availability, whereas N-addition favoured copiotrophic AOB. Overall, N-addition showed a low impact on soil diazotrophs and AOA while effects for AOB communities were considerable. These results reveal that long-term N-addition has important ecological implications for key microbial groups involved in two critical soil N-cycling processes. Increased AOB abundance and community shifts following N-addition may change soil N-cycling, as larger population sizes may promote higher rates of ammonia oxidation and subsequently increase N loss via gaseous and soil N-leaching. These findings bring us a step closer to predicting the responses and feedbacks of microbial-mediated N-cycling processes to long

Published
2022

3. Microbial processing of plant remains is co‐limited by multiple nutrients in global grasslands

Author

Ochoa-Hueso, R. (Raul), Borer, E. T. (Elizabeth T.), Seabloom, E. W. (Eric W.), Hobbie, S. E. (Sarah E.), Risch, A. C. (Anita C.), Collins, S. L. (Scott L.), Alberti, J. (Juan), Bahamonde, H. A. (Hector A.), Brown, C. S. (Cynthia S.), Caldeira, M. C. (Maria C.), Daleo, P. (Pedro), Dickman, C. R. (Chris R.), Ebeling, A. (Anne), Eisenhauer, N. (Nico), Esch, E. H. (Ellen H.), Eskelinen, A. (Anu), Fernandez, V. (Victoria), Gusewell, S. (Sabine), Gutierrez-Larruga, B. (Blanca), Hofmockel, K. (Kirsten), Laungani, R. (Ramesh), Lind, E. (Eric), Lopez, A. (Andrea), McCulley, R. L. (Rebecca L.), Moore, J. L. (Joslin L.), Peri, P. L. (Pablo L.), Power, S. A. (Sally A.), Price, J. N. (Jodi N.), Prober, S. M. (Suzanne M.), Roscher, C. (Christiane), Sarneel, J. M. (Judith M.), Schutz, M. (Martin), Siebert, J. (Julia), Standish, R. J. (Rachel J.), Ayuso, S. V. (Sergio Velasco), Virtanen, R. (Risto), Wardle, G. M. (Glenda M.), Wiehl, G. (Georg), Yahdjian, L. (Laura), and Zamin, T. (Tara)

Subjects
decomposition, eutrophication, fertilization, carbon cycling and sequestration, food and beverages, nutrient (co‐)limitation, microbial activity, NutNet
Abstract

Microbial processing of aggregate‐unprotected organic matter inputs is key for soil fertility, long‐term ecosystem carbon and nutrient sequestration and sustainable agriculture. We investigated the effects of adding multiple nutrients (nitrogen, phosphorus and potassium plus nine essential macro‐ and micro‐nutrients) on decomposition and biochemical transformation of standard plant materials buried in 21 grasslands from four continents. Addition of multiple nutrients weakly but consistently increased decomposition and biochemical transformation of plant remains during the peak‐season, concurrent with changes in microbial exoenzymatic activity. Higher mean annual precipitation and lower mean annual temperature were the main climatic drivers of higher decomposition rates, while biochemical transformation of plant remains was negatively related to temperature of the wettest quarter. Nutrients enhanced decomposition most at cool, high rainfall sites, indicating that in a warmer and drier future fertilized grassland soils will have an even more limited potential for microbial processing of plant remains.

Published
2020

4. Global impacts of fertilization and herbivore removal on soil net nitrogen mineralization are modulated by local climate and soil properties

Author

Risch, A. C. (Anita C.), Zimmermann, S. (Stefan), Moser, B. (Barbara), Schuetz, M. (Martin), Hagedorn, F. (Frank), Firn, J. (Jennifer), Fay, P. A. (Philip A.), Adler, P. B. (Peter B.), Biederman, L. A. (Lori A.), Blair, J. M. (John M.), Borer, E. T. (Elizabeth T.), Broadbent, A. A. (Arthur A. D.), Brown, C. S. (Cynthia S.), Cadotte, M. W. (Marc W.), Caldeira, M. C. (Maria C.), Davies, K. F. (Kendi F.), di Virgilio, A. (Augustina), Eisenhauer, N. (Nico), Eskelinen, A. (Anu), Knops, J. M. (Johannes M. H.), MacDougall, A. S. (Andrew S.), McCulley, R. L. (Rebecca L.), Melbourne, B. A. (Brett A.), Moore, J. L. (Joslin L.), Power, S. A. (Sally A.), Prober, S. M. (Suzanne M.), Seabloom, E. W. (Eric W.), Siebert, J. (Julia), Silveira, M. L. (Maria L.), Speziale, K. L. (Karina L.), Stevens, C. J. (Carly J.), Tognetti, P. M. (Pedro M.), Virtanen, R. (Risto), Yahdjian, L. (Laura), Ochoa-Hueso, R. (Raul), Risch, A. C. (Anita C.), Zimmermann, S. (Stefan), Moser, B. (Barbara), Schuetz, M. (Martin), Hagedorn, F. (Frank), Firn, J. (Jennifer), Fay, P. A. (Philip A.), Adler, P. B. (Peter B.), Biederman, L. A. (Lori A.), Blair, J. M. (John M.), Borer, E. T. (Elizabeth T.), Broadbent, A. A. (Arthur A. D.), Brown, C. S. (Cynthia S.), Cadotte, M. W. (Marc W.), Caldeira, M. C. (Maria C.), Davies, K. F. (Kendi F.), di Virgilio, A. (Augustina), Eisenhauer, N. (Nico), Eskelinen, A. (Anu), Knops, J. M. (Johannes M. H.), MacDougall, A. S. (Andrew S.), McCulley, R. L. (Rebecca L.), Melbourne, B. A. (Brett A.), Moore, J. L. (Joslin L.), Power, S. A. (Sally A.), Prober, S. M. (Suzanne M.), Seabloom, E. W. (Eric W.), Siebert, J. (Julia), Silveira, M. L. (Maria L.), Speziale, K. L. (Karina L.), Stevens, C. J. (Carly J.), Tognetti, P. M. (Pedro M.), Virtanen, R. (Risto), Yahdjian, L. (Laura), and Ochoa-Hueso, R. (Raul)

Abstract

Soil nitrogen (N) availability is critical for grassland functioning. However, human activities have increased the supply of biologically limiting nutrients, and changed the density and identity of mammalian herbivores. These anthropogenic changes may alter net soil N mineralization (soil net Nmin), that is, the net balance between N mineralization and immobilization, which could severely impact grassland structure and functioning. Yet, to date, little is known about how fertilization and herbivore removal individually, or jointly, affect soil net Nmin across a wide range of grasslands that vary in soil and climatic properties. Here we collected data from 22 grasslands on five continents, all part of a globally replicated experiment, to assess how fertilization and herbivore removal affected potential (laboratory‐based) and realized (field‐based) soil net Nmin. Herbivore removal in the absence of fertilization did not alter potential and realized soil net Nmin. However, fertilization alone and in combination with herbivore removal consistently increased potential soil net Nmin. Realized soil net Nmin, in contrast, significantly decreased in fertilized plots where herbivores were removed. Treatment effects on potential and realized soil net Nmin were contingent on site‐specific soil and climatic properties. Fertilization effects on potential soil net Nmin were larger at sites with higher mean annual precipitation (MAP) and temperature of the wettest quarter (T.q.wet). Reciprocally, realized soil net Nmin declined most strongly with fertilization and herbivore removal at sites with lower MAP and higher T.q.wet. In summary, our findings show that anthropogenic nutrient enrichment, herbivore exclusion and alterations in future climatic conditions can negatively impact soil net Nmin across global grasslands under realistic field conditions. This is an important context‐dependent knowledge for grassland management worldwide.

Published
2020

5. Asynchrony among local communities stabilises ecosystem function of metacommunities

Author

Wilcox, K. R. (Kevin R.), Tredennick, A. T. (Andrew T.), Koerner, S. E. (Sally E.), Grman, E. (Emily), Hallett, L. M. (Lauren M.), Avolio, M. L. (Meghan L.), La Pierre, K. J. (Kimberly J.), Houseman, G. R. (Gregory R.), Isbell, F. (Forest), Johnson, D. S. (David Samuel), Alatalo, J. M. (Juha M.), Baldwin, A. H. (Andrew H.), Bork, E. W. (Edward W.), Boughton, E. H. (Elizabeth H.), Bowman, W. D. (William D.), Britton, A. J. (Andrea J.), Cahill, J. F. (James F., Jr.), Collins, S. L. (Scott L.), Du, G. (Guozhen), Eskelinen, A. (Anu), Gough, L. (Laura), Jentsch, A. (Anke), Kern, C. (Christel), Klanderud, K. (Kari), Knapp, A. K. (Alan K.), Kreyling, J. (Juergen), Luo, Y. (Yiqi), McLaren, J. R. (Jennie R.), Megonigal, P. (Patrick), Onipchenko, V. (Vladimir), Prevey, J. (Janet), Price, J. N. (Jodi N.), Robinson, C. H. (Clare H.), Sala, O. E. (Osvaldo E.), Smith, M. D. (Melinda D.), Soudzilovskaia, N. A. (Nadejda A.), Souza, L. (Lara), Tilman, D. (David), White, S. R. (Shannon R.), Xu, Z. (Zhuwen), Yahdjian, L. (Laura), Yu, Q. (Qiang), Zhang, P. (Pengfei), Zhang, Y. (Yunhai), Wilcox, K. R. (Kevin R.), Tredennick, A. T. (Andrew T.), Koerner, S. E. (Sally E.), Grman, E. (Emily), Hallett, L. M. (Lauren M.), Avolio, M. L. (Meghan L.), La Pierre, K. J. (Kimberly J.), Houseman, G. R. (Gregory R.), Isbell, F. (Forest), Johnson, D. S. (David Samuel), Alatalo, J. M. (Juha M.), Baldwin, A. H. (Andrew H.), Bork, E. W. (Edward W.), Boughton, E. H. (Elizabeth H.), Bowman, W. D. (William D.), Britton, A. J. (Andrea J.), Cahill, J. F. (James F., Jr.), Collins, S. L. (Scott L.), Du, G. (Guozhen), Eskelinen, A. (Anu), Gough, L. (Laura), Jentsch, A. (Anke), Kern, C. (Christel), Klanderud, K. (Kari), Knapp, A. K. (Alan K.), Kreyling, J. (Juergen), Luo, Y. (Yiqi), McLaren, J. R. (Jennie R.), Megonigal, P. (Patrick), Onipchenko, V. (Vladimir), Prevey, J. (Janet), Price, J. N. (Jodi N.), Robinson, C. H. (Clare H.), Sala, O. E. (Osvaldo E.), Smith, M. D. (Melinda D.), Soudzilovskaia, N. A. (Nadejda A.), Souza, L. (Lara), Tilman, D. (David), White, S. R. (Shannon R.), Xu, Z. (Zhuwen), Yahdjian, L. (Laura), Yu, Q. (Qiang), Zhang, P. (Pengfei), and Zhang, Y. (Yunhai)

Abstract

Temporal stability of ecosystem functioning increases the predictability and reliability of ecosystem services, and understanding the drivers of stability across spatial scales is important for land management and policy decisions. We used species-level abundance data from 62 plant communities across five continents to assess mechanisms of temporal stability across spatial scales. We assessed how asynchrony (i.e. different units responding dissimilarly through time) of species and local communities stabilised metacommunity ecosystem function. Asynchrony of species increased stability of local communities, and asynchrony among local communities enhanced metacommunity stability by a wide range of magnitudes (1–315%); this range was positively correlated with the size of the metacommunity. Additionally, asynchronous responses among local communities were linked with species’ populations fluctuating asynchronously across space, perhaps stemming from physical and/or competitive differences among local communities. Accordingly, we suggest spatial heterogeneity should be a major focus for maintaining the stability of ecosystem services at larger spatial scales.

Published
2017

Catalog

Books, media, physical & digital resources
See catalog results