Terrestrial phosphorus limitation: mechanisms, implications, and nitrogen–phosphorus interactions

Ecological Applications, Год журнала: 2010, Номер 20(1), С. 5 - 15

Опубликована: Янв. 1, 2010

Nutrient limitation to primary productivity and other biological processes is widespread in terrestrial ecosystems, nitrogen (N) phosphorus (P) are the most common limiting elements, both individually combination. Mechanisms that drive P limitation, their interactions with N cycle, have received less attention than mechanisms causing limitation. We identify discuss six could ecosystems. The best known of these depletion‐driven which accumulated losses during long‐term soil ecosystem development contribute what Walker Syers termed a “terminal steady state” profound depletion barriers prevent access P; transactional weathering P‐containing minerals does not keep pace supply resources; low‐P parent materials; sinks; anthropogenic changes increase resources (often N) relative P. distinguish proximate nutrient (which occurs where additions stimulate processes, especially productivity) from ultimate (where can transform ecosystems). Of we suggest depletion, barriers, material often cause because they control mass balance Similarly, demand‐independent constraints fixation ecosystem‐level it be an nutrient.

Язык: Английский

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Comparative metagenomic, phylogenetic and physiological analyses of soil microbial communities across nitrogen gradients

The ISME Journal, Год журнала: 2011, Номер 6(5), С. 1007 - 1017

Опубликована: Дек. 1, 2011

Abstract Terrestrial ecosystems are receiving elevated inputs of nitrogen (N) from anthropogenic sources and understanding how these increases in N availability affect soil microbial communities is critical for predicting the associated effects on belowground ecosystems. We used a suite approaches to analyze structure functional characteristics replicated plots two long-term fertilization experiments located contrasting systems. Pyrosequencing-based analyses 16S rRNA genes revealed no significant bacterial diversity, but community composition at both sites; copiotrophic taxa (including members Proteobacteria Bacteroidetes phyla) typically increased relative abundance high plots, with oligotrophic (mainly Acidobacteria) exhibiting opposite pattern. Consistent phylogenetic shifts under fertilization, shotgun metagenomic sequencing abundances DNA/RNA replication, electron transport protein metabolism, that could be resolved even shallow conducted here (average 75 000 reads per sample). also observed catabolic capabilities across gradients were significantly correlated responses, indicating possible linkages between functioning communities. Overall, our results suggest may, directly or indirectly, induce shift predominant life-history strategies, favoring more active, community, pattern parallels often replacement K-selected r-selected plant species N.

Язык: Английский

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Nitrogen additions and microbial biomass: a meta‐analysis of ecosystem studies

Ecology Letters, Год журнала: 2008, Номер 11(10), С. 1111 - 1120

Опубликована: Июль 31, 2008

Abstract Nitrogen (N) enrichment is an element of global change that could influence the growth and abundance many organisms. In this meta‐analysis, I synthesized responses microbial biomass to N additions in 82 published field studies. hypothesized fungi, bacteria or community as a whole would be altered under additions. also predicted changes parallel soil CO 2 emissions. Microbial declined 15% on average fertilization, but fungi were not significantly studies examined each group separately. Moreover, declines microbes more evident longer durations with higher total amounts added. addition, fertilization correlated There no significant effects biomes, fertilizer types, ambient deposition rates methods measuring biomass. Altogether, these results suggest reduce ecosystems, corresponding

Язык: Английский

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Rethinking Community Assembly through the Lens of Coexistence Theory

Annual Review of Ecology Evolution and Systematics, Год журнала: 2012, Номер 43(1), С. 227 - 248

Опубликована: Авг. 30, 2012

Although research on the role of competitive interactions during community assembly began decades ago, a recent revival interest has led to new discoveries and opportunities. Using contemporary coexistence theory that emphasizes stabilizing niche differences relative fitness differences, we evaluate three empirical approaches for studying assembly. We show experimental manipulations abiotic or biotic environment, assessments trait-phylogeny-environment relationships, investigations frequency-dependent population growth all suggest strong influences outcome plant Nonetheless, due limitations these applied in isolation, still have poor understanding which axes traits determine competition structure. Combining current represents our best chance achieving this goal, is fundamental conceptual ecology management communities under global change.

Язык: Английский

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Competition for Light Causes Plant Biodiversity Loss After Eutrophication

Science, Год журнала: 2009, Номер 324(5927), С. 636 - 638

Опубликована: Апрель 30, 2009

Human activities have increased the availability of nutrients in terrestrial and aquatic ecosystems. In grasslands, this eutrophication causes loss plant species diversity, but mechanism has been difficult to determine. Using experimental grassland communities, we found that addition light understory prevented biodiversity caused by eutrophication. There was no detectable role for competition soil resources diversity loss. Thus, is a major after explains particular threat diversity. Our conclusions implications management conservation policy underscore need control nutrient enrichment if be preserved.

Язык: Английский

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Consistent responses of soil microbial communities to elevated nutrient inputs in grasslands across the globe

Proceedings of the National Academy of Sciences, Год журнала: 2015, Номер 112(35), С. 10967 - 10972

Опубликована: Авг. 17, 2015

Significance Human activities have resulted in large increases the availability of nutrients terrestrial ecosystems worldwide. Although plant community responses to elevated been well studied, soil microbial remain poorly understood, despite their critical importance ecosystem functioning. Using DNA-sequencing approaches, we assessed response communities experimentally added nitrogen and phosphorus at 25 grassland sites across globe. Our results demonstrate that composition these shifts consistent ways with nutrient inputs there are corresponding ecological attributes members. This study represents an important step forward for understanding connection between inputs, communities, altered

Язык: Английский

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Community assembly and shifts in plant trait distributions across an environmental gradient in coastal California

Ecological Monographs, Год журнала: 2009, Номер 79(1), С. 109 - 126

Опубликована: Фев. 1, 2009

Community assembly processes are thought to shape the mean, spread, and spacing of functional trait values within communities. Two broad categories have been proposed: first, a habitat filter that restricts range viable strategies second, partitioning microsites and/or resources leads limit similarity coexisting species. The strength both may be dependent on conditions at particular site change along an abiotic gradient. We sampled environmental variables plant communities in 44 plots across varied topography coastal California landscape. characterized 14 leaf, stem, root traits for 54 woody species, including detailed intraspecific data two with goal understanding connection between variety conditions. examined within‐community range, variance, kurtosis, other measures values. In this landscape, there was topographically mediated gradient water availability. Across we observed strong shifts plot‐level mean variation Trends means environment were due largely species turnover, playing smaller role. Traits associated vertical light showed greater variance wet soils, while nitrogen per area, which is use efficiency, spread dry soils. found nonrandom patterns distributions consistent expectations based trait‐mediated community assembly. There significant reduction six out 11 leaf stem relative null model. For specific area (SLA) even seed size more platykurtic distribution than expected. These results suggest can simultaneously local

Язык: Английский

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Nitrogen in Agriculture: Balancing the Cost of an Essential Resource

Annual Review of Environment and Resources, Год журнала: 2009, Номер 34(1), С. 97 - 125

Опубликована: Окт. 15, 2009

Nitrogen (N) is central to living systems, and its addition agricultural cropping systems an essential facet of modern crop management one the major reasons that production has kept pace with human population growth. The benefits N added come, however, at well-documented environmental costs: Increased coastal hypoxia, atmospheric nitrous oxide (N 2 O), reactive gases in troposphere, deposition onto forests other natural areas are some consequences our inability keep fertilizer from leaving cropped ecosystems via unmanaged pathways. cycle complex, solutions require a thorough understanding both biogeochemical pathways different practices. Despite complexity this challenge, number technologies available today reduce loss. These include adding rotational improve capture by crops, providing farmers decision support tools for better predicting requirements, improving methods optimizing timing placement, developing watershed-level strategies recapture lost fields. Solutions problem loss will portfolio approach which used combinations address site-specific challenges. also incentives promote their adoption.

Язык: Английский

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Loss of plant species after chronic low-level nitrogen deposition to prairie grasslands

Nature, Год журнала: 2008, Номер 451(7179), С. 712 - 715

Опубликована: Фев. 1, 2008

Язык: Английский

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Assessing functional diversity in the field – methodology matters!

Functional Ecology, Год журнала: 2007, Номер 22(1), С. 134 - 147

Опубликована: Ноя. 22, 2007

1 Interpreting the functional diversity of vegetation is important in unravelling relationship between environmental change, community composition and ecosystem processes. Functional range distribution trait values a community. It can be described, among other indicators, by community-level weighted means (CWM) divergence. Standard methods exist for measurements but not assessments CWM divergence field. No research has addressed effects different estimating relative abundances, nor need to estimate traits at individual, population or species level, whether could used that bypass taxonomy all together. 2 This study reviews evaluates plot-level assessment herbaceous vegetation. We asked: (i) Should objective influence method abundance? (ii) What are strengths limitations intensive vs. 'rapid' approaches, when should either applied? (iii) Are taxon-free robust comparison taxon-explicit measurement? Under what circumstances might they 3 Our review published studies have measured field showed choice metric generally taken into account link functions interest, cover been most widely used, regardless purpose. 4 compared quantitatively subalpine grasslands three quantification abundances plus one method. found that: data base were across years diverse set dominant species; little sensitivity abundances; this also depends on traits, example, seed mass results less stable than leaf heights; estimates obtained from visual ranks biomass using dry-weight ranking (BOTANAL), whereas was more sensitive method; (iv) treated with caution performed particularly poorly 5 conclude methodology affect diversity. Although care interpretation results, rapid often offer promising avenues sampling larger areas and/or repeated measures.

Язык: Английский

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