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A growing body of work examines the direct and indirect effects of climate change on ecosystems, typically by using manipulative experiments at a single site or performing meta-analyses across many independent experiments. However, results from single-site studies tend to have limited generality. Although meta-analytic approaches can help overcome this by exploring trends across sites, the inherent limitations in combining disparate datasets from independent approaches remain a major challenge. In this paper, we present a globally distributed experimental network that can be used to disentangle the direct and indirect effects of climate change. We discuss how natural gradients, experimental approaches, and statistical techniques can be combined to best inform predictions about responses to climate change, and we present a globally distributed experiment that utilizes natural environmental gradients to better understand long-term community and ecosystem responses to environmental change. The warming and (species) removal in mountains (WaRM) network employs experimental warming and plant species removals at high- and low-elevation sites in a factorial design to examine the combined and relative effects of climatic warming and the loss of dominant species on community structure and ecosystem function, both above- and belowground. The experimental design of the network allows for increasingly common statistical approaches to further elucidate the direct and indirect effects of warming. We argue that combining ecological observations and experiments along gradients is a powerful approach to make stronger predictions of how ecosystems will function in a warming world as species are lost, or gained, in local communities.

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. Weassessed 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 withthe 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 suggestspatial heterogeneity should be a major focus for maintaining the stability of ecosystem services at larger spatial scales.

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. Fil: Wilcox, Kevin R.. Oklahoma State University; Estados Unidos Fil: Tredennick, Andrew T.. State University of Utah; Estados Unidos Fil: Koerner, Sally E.. University of North Carolina; Estados Unidos Fil: Grman, Emily. Eastern Michigan University; Estados Unidos Fil: Hallett, Lauren M.. University of Oregon; Estados Unidos Fil: Avolio, Meghan L.. University Johns Hopkins; Estados Unidos Fil: La Pierre, Kimberly J.. Smithsonian Environmental Research Center; Estados Unidos Fil: Houseman, Gregory R.. Wichita State University; Estados Unidos Fil: Forest, Isbell. University of Minnesota; Estados Unidos Fil: Johnson, David Samuel. Virginia Institute of Marine Science; Estados Unidos Fil: Alatalo, Juha M.. Qatar University; Qatar Fil: Baldwin, Andrew H.. University of Maryland; Estados Unidos Fil: Bork, Edward W.. University of Alberta; Canadá Fil: Boughton, Elizabeth H.. MacArthur Agroecology Research Center; Estados Unidos Fil: Bowman, William D.. University of Colorado; Estados Unidos Fil: Britton, Andrea J.. James Hutton Institute; Estados Unidos Fil: Cahill, James F.. University of Alberta; Canadá Fil: Collins, Scott L.. University of New Mexico; Estados Unidos Fil: Du, Guozhen. Lanzhou University; China Fil: Eskelinen, Anu. Helmholtz Centre for Environmental Research; Alemania. German Centre for Integrative Biodiversity Research; Alemania. University of Oulu; Finlandia Fil: Gough, Laura. Towson University; Estados Unidos Fil: Jentsch, Anke. University of Bayreuth; Alemania Fil: Kern, Christel. United States Forest Service; Estados Unidos Fil: Klanderud, Kari. Norwegian University of Life Sciences; Noruega Fil: Knapp, Alan K.. Colorado State University; Estados Unidos Fil: Kreyling, Juergen. Greifswald University; Alemania Fil: Luo, Yiqi. Oklahoma State University; Estados Unidos. Northern Arizona University; Estados Unidos. Tsinghua University; China Fil: McLaren, James E.. University of Texas at El Paso; Estados Unidos Fil: Megonigal, Patrick. Smithsonian Environmental Research Center; Estados Unidos Fil: Onipchenko, Vladimir. Moscow State Lomonosov University; Rusia Fil: Prevéy, Janet. Pacific Northwest Research Station; Estados Unidos Fil: Price, Jodi N.. Charles Sturt University; Australia Fil: Robinson, Clare H.. University of Manchester; Reino Unido Fil: Sala, Osvaldo Esteban. Arizona State University; Estados Unidos. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Parque Centenario. Instituto de Investigaciones Fisiológicas y Ecológicas Vinculadas a la Agricultura. Universidad de Buenos Aires. Facultad de Agronomía; Argentina Fil: Smith, Melinda D.. Colorado State University; Estados Unidos Fil: Soudzilovskaia, Nadejda A.. Leiden University; Países Bajos Fil: Souza, Lara. Oklahoma State University; Estados Unidos Fil: Tilman, David. University of Minnesota; Estados Unidos Fil: White, Shannon R.. Government of Alberta; Canadá Fil: Xu, Zhuwen. Chinese Academy of Sciences; República de China Fil: Yahdjian, María Laura. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Parque Centenario. Instituto de Investigaciones Fisiológicas y Ecológicas Vinculadas a la Agricultura. Universidad de Buenos Aires. Facultad de Agronomía; Argentina Fil: Yu, Qiang. Chinese Academy of Agricultural Sciences; China Fil: Zhang, Pengfei. Lanzhou University; China Fil: Zhang, Yunhai. Chinese Academy of Sciences; República de China. University Aarhus; Dinamarca

In desert soils, phosphorus (P) cycling is controlled by both geochemical and biological factors and remains less studied than nitrogen and carbon. We examined these P cycling factors in the context of biological soil crusts (biocrusts), which are important drivers of nutrient cycling in drylands and have the potential to release bound labile P. We adopted the biologically-based P (BBP) method, which allows examination of biologically relevant P fractions. The BBP method incorporates four extractions: dilute calcium chloride (CaCl2), citric acid, phosphatase enzymes, and hydrochloric acid (HCl). We coupled the extractions with a 33P-labeled orthophosphate addition and incubation to assess the fate of freshly available phosphate (PO43&minus, ). Low P concentrations in the dilute CaCl2 extractions suggest that drylands lack accessible P in the soil solution, while higher amounts in the citric acid- and enzyme-extractable pools suggest that dryland microbes may acquire P through the release of organic acids and phosphatases. The addition of 33PO43&minus, was, within 24 h, quickly adsorbed onto mineral surfaces or incorporated into hydrolysable organic compounds. Areas with biocrusts showed overall lower P concentrations across all four extractable pools. This suggests that biocrust organisms may prevent P adsorption onto mineral surfaces by incorporating P into their biomass. Overall, our results indicate that organisms may have to employ several viable strategies, including organic acid and enzyme production, to access P in dryland soils.