Abstract:
:Studies of soil nitrogen (N) availability over stand development have almost exclusively focused on mineral N, yet we increasingly recognize that plants can take up organic N in the form of free amino acids at biologically important rates. We investigated amino-acid and mineral N availability along a 10-site chronosequence of jack pine stands, varying in age from 4 to 60 yr following wildfire. We measured free amino-acid N and mineral N in soil extracts; native proteolytic rates; net N mineralization rates; and microbial amino-acid consumption via a 15N leucine tracer assay in 6 of the 10 sites (4, 10, 18, 22, 46, and 55-yr-old). Amino-acid N was consistently low in the youngest sites (4-10 yr), increased rapidly in mid-aged sites (15-22 yr), and was highest in stand age 46. In contrast, mineral N exhibited a parabolic shape (R2 0.499; P < 0.0001), with the youngest site and the four oldest sites containing the highest amounts of mineral N. As a result, amino-acid N as a percentage of amino-acid N + mineral N was greatest in mid-aged stands (e.g., 67% in the 22-yr-old stand). We observed no trend in proteolytic rates across the chronosequence (P = 0.632). Percentage 15N tracer recovery was lowest in the extractable organic N pool for the 4, 10, and 18-yr-old sites, though only site age 10 was significantly different from the older sites. Percentage of recovery in the organic N pool was significantly positively related (R2 = 0.798; P < 0.05) to standing pools of amino-acid N. Overall, our results suggest that heterotrophic consumption, not production via proteolysis, controls soil free amino-acid availability. Higher microbial demand for free amino acids in younger vs. older sites likely results from greater microbial C and N limitation early in stand development due to the lack of fresh litter inputs. Since aminoacid N exceeds mineral N in a time period of stand development where jack pine growth rates and N demand are highest, we speculate that amino-acid N may be important to the N economy of these forests.
journal_name
Ecologyjournal_title
Ecologyauthors
LeDuc SD,Rothstein DEdoi
10.1890/09-0140.1subject
Has Abstractpub_date
2010-03-01 00:00:00pages
708-20issue
3eissn
0012-9658issn
1939-9170journal_volume
91pub_type
杂志文章相关文献
ECOLOGY文献大全abstract::In tropical forests, resource-based niches and density-dependent mortality are mutually compatible mechanisms that can act simultaneously to limit seedling populations. Differences in the strengths of these mechanisms will determine their roles in maintaining species coexistence. In the first assessment of these mecha...
journal_title:Ecology
pub_type: 杂志文章
doi:10.1890/11-0894.1
更新日期:2012-03-01 00:00:00
abstract::The pervasive impact of invasive species has motivated considerable research to understand how characteristics of invaded communities, such as native species diversity, affect the establishment of invasive species. Efforts to identify general mechanisms that limit invasion success, however, have been frustrated by dis...
journal_title:Ecology
pub_type: 杂志文章
doi:10.1890/09-1301.1
更新日期:2010-05-01 00:00:00
abstract::Effects of predation may cascade down the food web. By alleviating interspecific competition among prey, predators may promote biodiversity, but the precise mechanisms of how predators alter competition have remained elusive. Here we report on a predator-exclosure experiment carried out in a tropical intertidal ecosys...
journal_title:Ecology
pub_type: 杂志文章
doi:10.1890/11-1282.1
更新日期:2012-05-01 00:00:00
abstract::Leaving a population without having information about the surrounding areas is highly risky. Candidates for dispersal may reduce these risks by making decisions based on the level of connectivity between patches, e.g., through immigrants. The benefits of information acquisition may vary within a population according t...
journal_title:Ecology
pub_type: 杂志文章
doi:10.1890/09-0387.1
更新日期:2010-05-01 00:00:00
abstract::Fundamental gaps remain in our knowledge of how positive species interactions, such as facilitation and mutualism, structure and maintain populations and communities. Foundation species create extensive biogenic habitats, but we know little of how their traits, such as density, age, and patch size, modify their abilit...
journal_title:Ecology
pub_type: 杂志文章
doi:10.1890/08-1957.1
更新日期:2009-11-01 00:00:00
abstract::Kelp systems dominate nearshore marine environments in upwelling zones characterized by cold temperatures and high nutrients. Worldwide, kelp population persistence and recruitment success generally decreases with rising water temperatures coupled with low nutrients, making kelp populations vulnerable to impending war...
journal_title:Ecology
pub_type: 杂志文章
doi:10.1002/ecy.2594
更新日期:2019-03-01 00:00:00
abstract::The ecological impact of rapid environmental change will depend on the resistance of key ecosystems processes, which may be promoted by species that exert strong control over local environmental conditions. Recent theoretical work suggests that macrodetritivores increase the resistance of African savanna ecosystems to...
journal_title:Ecology
pub_type: 杂志文章
doi:10.1002/ecy.1658
更新日期:2017-02-01 00:00:00
abstract::Evidence from woodrat middens and tree rings at Dutch John Mountain (DJM) in northeastern Utah reveal spatiotemporal patterns of pinyon pine (Pinus edulis Engelm.) colonization and expansion in the past millennium. The DJM population, a northern outpost of pinyon, was established by long-distance dispersal (approximat...
journal_title:Ecology
pub_type: 杂志文章
doi:10.1890/0012-9658(2006)87[1124:romcvi]2.0.co;2
更新日期:2006-05-01 00:00:00
abstract::Food webs of freshwater ecosystems can be subsidized by allochthonous resources. However, it is still unknown which environmental factors regulate the relative consumption of allochthonous resources in relation to autochthonous resources. Here, we evaluated the importance of allochthonous resources (litterfall) for th...
journal_title:Ecology
pub_type: 杂志文章
doi:10.1002/ecy.1432
更新日期:2016-08-01 00:00:00
abstract::The spatial distribution of species is not random; instead, individuals tend to gather, resulting in a non-random pattern. Previous studies used the independent negative binomial distribution (NBD) to model the distributional aggregation of a single species, in which the independence of the distribution of individuals...
journal_title:Ecology
pub_type: 杂志文章
doi:10.1002/ecy.2544
更新日期:2018-12-01 00:00:00
abstract::Plant species composition and diversity is often influenced by early life history stages; thus, global change could dramatically affect plant community structure by altering seed production. Unfortunately, plant reproductive responses to global change are rarely studied in field settings, making it difficult to assess...
journal_title:Ecology
pub_type: 杂志文章
doi:10.1890/07-1351.1
更新日期:2009-07-01 00:00:00
abstract::The nature of nutrient limitation in large areas of temperate forest may be changing due to human activities. As N availability in these forests increases, other nutrients could increasingly constrain productivity and other ecosystem processes. To determine the nature of nutrient limitation (N, P, and Ca) in forest so...
journal_title:Ecology
pub_type: 杂志文章
doi:10.1890/0012-9658(2007)88[119:nlised]2.0.co;2
更新日期:2007-01-01 00:00:00
abstract::Within the context of species distribution models, scrutiny arises from the choice of meaningful environmental predictors. Thermal conditions are not the sole driver, but are the most widely acknowledged abiotic driver of plant life within alpine ecosystems. We linked long-term measurements of direct, plant-relevant, ...
journal_title:Ecology
pub_type: 杂志文章
doi:10.1002/ecy.2891
更新日期:2020-01-01 00:00:00
abstract::Although invasive species can have substantial impacts on animal communities, cases of invasive species facilitating native species by removing their predators have rarely been demonstrated across vertebrate trophic linkages. The predictable spread of the invasive cane toad (Rhinella marina), however, offered a unique...
journal_title:Ecology
pub_type: 杂志文章
doi:10.1890/14-1332.1
更新日期:2015-09-01 00:00:00
abstract::Prolonged droughts exacerbated by climate change have been widely documented to interact with consumers to decimate vegetation in many ecosystems. Although climate change is increasing within-year variation in precipitation and temperature, how weather fluctuations affect the impact of consumers on vegetation processe...
journal_title:Ecology
pub_type: 杂志文章
doi:10.1002/ecy.2559
更新日期:2019-01-01 00:00:00
abstract::Species intolerant of changing climate might avoid extinction within refugia buffered from extreme conditions. Refugia have been observed in the fossil record but are not well documented or understood on ecological time scales. Using a 37-year record from the eastern Pacific across the two most severe El Niño events o...
journal_title:Ecology
pub_type: 杂志文章
doi:10.1890/13-0468.1
更新日期:2014-06-01 00:00:00
abstract::Avian dispersal of seeds of the wild olive tree (Olea europaea var. sylvestris) was studied in Mediterranean shrubland, southern Spain. Fourteen species of small frugivorous birds in the genera Sylvia, Turdus, Sturnus, and Erithacus accounted for 97.4% of the fruits consumed by birds. The significance of each bird spe...
journal_title:Ecology
pub_type: 杂志文章
doi:10.2307/1939863
更新日期:1987-12-01 00:00:00
abstract::Host nutrition is thought to affect the establishment, persistence, and severity of pathogenic infections. Nutrient-deficient foods possibly benefit pathogens by constraining host immune function or benefit hosts by limiting parasite growth and reproduction. However, the effects of poor elemental food quality on a hos...
journal_title:Ecology
pub_type: 杂志文章
doi:10.1890/07-0389.1
更新日期:2008-02-01 00:00:00
abstract::Most hypotheses explaining the general gradient of higher diversity toward the equator are implicit or explicit about greater species packing in the tropics. However, global patterns of diversity within guilds, including trophic guilds (i.e., groups of organisms that use similar food resources), are poorly known. We e...
journal_title:Ecology
pub_type: 杂志文章
doi:10.1890/10-2244.1
更新日期:2011-09-01 00:00:00
abstract::Because sea otters (Enhydra lutris) exert a wide array of direct and indirect effects on coastal marine ecosystems throughout their geographic range, we investigated the potential influence of sea otters on the ecology of Bald Eagles (Haliaeetus leucocephalus) in the Aleutian Islands, Alaska, USA. We studied the diets...
journal_title:Ecology
pub_type: 杂志文章
doi:10.1890/07-1818.1
更新日期:2008-10-01 00:00:00
abstract::Mires (bogs and fens) are nutrient-limited peatland ecosystems, the vegetation of which is especially sensitive to nitrogen deposition and climate change. The role of mires in the global carbon cycle, and the delivery of different ecosystem services can be considerably altered by changes in the vegetation, which has a...
journal_title:Ecology
pub_type: 杂志文章
doi:10.1002/ecy.1627
更新日期:2017-01-01 00:00:00
abstract::The relative importance of bottom-up or top-down forces has been mainly studied for herbivores but rarely for pollinators. Habitat fragmentation might change driving forces of population dynamics by reducing the area of resource-providing habitats, disrupting habitat connectivity, and affecting natural enemies more th...
journal_title:Ecology
pub_type: 杂志文章
doi:10.1890/06-1323.1
更新日期:2008-05-01 00:00:00
abstract::Most taxa show consistent individual differences in behavior, a phenomenon often referred to as animal "personalities." While the links between individual personality and fitness have received considerable attention, little information is available on how animal personality impacts higher-order ecological processes, s...
journal_title:Ecology
pub_type: 杂志文章
doi:10.1890/14-2424.1
更新日期:2015-11-01 00:00:00
abstract::In large samples of trees > or = 1 cm dbh (more than 1 million trees and 3000 species), in six lowland tropical forests on three continents, we assigned species with >30 individuals to one of six classes of stature at maturity (SAM). We then compared the proportional representation of understory trees (1-2 cm dbh) amo...
journal_title:Ecology
pub_type: 杂志文章
doi:10.1890/0012-9658(2006)87[2298:csacot]2.0.co;2
更新日期:2006-09-01 00:00:00
abstract::Species abundances in natural systems are usually close to some equilibrium, making mechanisms that maintain or prevent species coexistence difficult to discern. Biological control projects provide an opportunity to observe systems transition between equilibriums as a result of the influence of the newly introduced sp...
journal_title:Ecology
pub_type: 杂志文章
doi:10.1890/08-0852.1
更新日期:2009-05-01 00:00:00
abstract::Climatic extremes, such as severe drought, are expected to increase in frequency and magnitude with climate change. Thus, identifying mechanisms of resilience is critical to predicting the vulnerability of ecosystems. An exceptional drought ( journal_title:Ecology pub_type: 杂志文章 doi:10.1002/ecy.2983 更新日期:2020-04-01 00:00:00
abstract::Herbivores may directly or indirectly affect plant attractiveness to pollinators. Although several studies have reported on these effects, there is yet no general consensus on the strength and sign of such interactions or their contingency on herbivory features such as the plant tissue attacked. We performed a meta-an...
journal_title:Ecology
pub_type: 杂志文章,meta分析
doi:10.1002/ecy.2707
更新日期:2019-06-01 00:00:00
abstract::Factors controlling the spatial distribution of bacterial diversity have been intensely studied, whereas less is known about temporal changes. To address this, we tested whether the mechanisms that underlie bacterial temporal beta-diversity vary across different scales in three marine microbial communities. While seas...
journal_title:Ecology
pub_type: 杂志文章
doi:10.1890/12-2125.1
更新日期:2013-09-01 00:00:00
abstract::Hydraulic traits are important for woody plant functioning and distribution. Associations among hydraulic traits, other leaf and stem traits, and species' performance are relatively well understood for trees, but remain poorly studied for lianas. We evaluated the coordination among hydraulic efficiency (i.e., maximum ...
journal_title:Ecology
pub_type: 杂志文章
doi:10.1002/ecy.2666
更新日期:2019-05-01 00:00:00
abstract::Photoautotrophs are generally considered to be the base of food webs, and habitats that lack light, such as caves, frequently rely on surface-derived carbon. Here we show, based on analysis of gut contents and stable isotope ratios of tissues (13C:12C and 15N:14N), that sulfur-oxidizing bacteria are directly consumed ...
journal_title:Ecology
pub_type: 杂志文章
doi:10.1890/11-0276.1
更新日期:2011-11-01 00:00:00