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Phosphate addition enhanced soil inorganic nutrients to a large extent in three tropical forests.

Zhu F, Lu X, Liu L, Mo J - Sci Rep (2015)

Bottom Line: In contrast, besides great elevation in soil available P, P treatments induced 60%, 50%, 26% increases in sum of exchangeable (K(+)+Ca(2+)+Mg(2+)) in the old-growth and the two younger forests, respectively.These positive effects of P were closely related to P-stimulated microbial biomass and litter nutrient input, implying possible stimulation of nutrient return.Our results suggest that N deposition may result in decreases in soil inorganic nutrients (except N) and that P addition can enhance soil inorganic nutrients to support ecosystem processes in these tropical forests.

View Article: PubMed Central - PubMed

Affiliation: 1] Key Laboratory of Vegetation Restoration and Management of Degraded Ecosystems, South China Botanical Garden, Chinese Academy of Sciences, Guangzhou 510650, China [2] Forest and Soil Ecology, Institute of Applied Ecology, Chinese Academy of Sciences, Shenyang 110164, China.

ABSTRACT
Elevated nitrogen (N) deposition may constrain soil phosphorus (P) and base cation availability in tropical forests, for which limited evidence have yet been available. In this study, we reported responses of soil inorganic nutrients to full factorial N and P treatments in three tropical forests different in initial soil N status (N-saturated old-growth forest and two less-N-rich younger forests). Responses of microbial biomass, annual litterfall production and nutrient input were also monitored. Results showed that N treatments decreased soil inorganic nutrients (except N) in all three forests, but the underlying mechanisms varied depending on forests: through inhibition on litter decomposition in the old-growth forest and through Al(3+) replacement of Ca(2+) in the two younger forests. In contrast, besides great elevation in soil available P, P treatments induced 60%, 50%, 26% increases in sum of exchangeable (K(+)+Ca(2+)+Mg(2+)) in the old-growth and the two younger forests, respectively. These positive effects of P were closely related to P-stimulated microbial biomass and litter nutrient input, implying possible stimulation of nutrient return. Our results suggest that N deposition may result in decreases in soil inorganic nutrients (except N) and that P addition can enhance soil inorganic nutrients to support ecosystem processes in these tropical forests.

Show MeSH
Soil microbial biomass carbon (a) and annual total litterfall production (b) in surface mineral soil from the three forests after 2.5 years of N and P additions.Bars indicate +1 SE (N = 5). Different capital letters indicate significant differences among the three study forests (One-way ANOVA, Tukey'b test, P < 0.05). Different lowercase letters indicate significant differences among treatments in each forest (One-way ANOVA, Tukey'b test, P < 0.05).
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f3: Soil microbial biomass carbon (a) and annual total litterfall production (b) in surface mineral soil from the three forests after 2.5 years of N and P additions.Bars indicate +1 SE (N = 5). Different capital letters indicate significant differences among the three study forests (One-way ANOVA, Tukey'b test, P < 0.05). Different lowercase letters indicate significant differences among treatments in each forest (One-way ANOVA, Tukey'b test, P < 0.05).

Mentions: In the old-growth forest, N treatments decreased soil available P by 72% (1.76 mg kg−1 in control to 0.49 mg kg−1 in N addition plots; Fig. 1b), had no effect on pH or any single exchangeable cation species (Fig. 1a; Table S1), but resulted in a 6% decrease in sum of exchangeable (K++Ca2++Mg2+) (One-way ANOVA, LSD test, P < 0.05; Fig. 2). N additions did not affect MBC, annual litterfall production, or annual litter nutrient input (Fig. 3; Table 1) in the old-growth forest.


Phosphate addition enhanced soil inorganic nutrients to a large extent in three tropical forests.

Zhu F, Lu X, Liu L, Mo J - Sci Rep (2015)

Soil microbial biomass carbon (a) and annual total litterfall production (b) in surface mineral soil from the three forests after 2.5 years of N and P additions.Bars indicate +1 SE (N = 5). Different capital letters indicate significant differences among the three study forests (One-way ANOVA, Tukey'b test, P < 0.05). Different lowercase letters indicate significant differences among treatments in each forest (One-way ANOVA, Tukey'b test, P < 0.05).
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4300498&req=5

f3: Soil microbial biomass carbon (a) and annual total litterfall production (b) in surface mineral soil from the three forests after 2.5 years of N and P additions.Bars indicate +1 SE (N = 5). Different capital letters indicate significant differences among the three study forests (One-way ANOVA, Tukey'b test, P < 0.05). Different lowercase letters indicate significant differences among treatments in each forest (One-way ANOVA, Tukey'b test, P < 0.05).
Mentions: In the old-growth forest, N treatments decreased soil available P by 72% (1.76 mg kg−1 in control to 0.49 mg kg−1 in N addition plots; Fig. 1b), had no effect on pH or any single exchangeable cation species (Fig. 1a; Table S1), but resulted in a 6% decrease in sum of exchangeable (K++Ca2++Mg2+) (One-way ANOVA, LSD test, P < 0.05; Fig. 2). N additions did not affect MBC, annual litterfall production, or annual litter nutrient input (Fig. 3; Table 1) in the old-growth forest.

Bottom Line: In contrast, besides great elevation in soil available P, P treatments induced 60%, 50%, 26% increases in sum of exchangeable (K(+)+Ca(2+)+Mg(2+)) in the old-growth and the two younger forests, respectively.These positive effects of P were closely related to P-stimulated microbial biomass and litter nutrient input, implying possible stimulation of nutrient return.Our results suggest that N deposition may result in decreases in soil inorganic nutrients (except N) and that P addition can enhance soil inorganic nutrients to support ecosystem processes in these tropical forests.

View Article: PubMed Central - PubMed

Affiliation: 1] Key Laboratory of Vegetation Restoration and Management of Degraded Ecosystems, South China Botanical Garden, Chinese Academy of Sciences, Guangzhou 510650, China [2] Forest and Soil Ecology, Institute of Applied Ecology, Chinese Academy of Sciences, Shenyang 110164, China.

ABSTRACT
Elevated nitrogen (N) deposition may constrain soil phosphorus (P) and base cation availability in tropical forests, for which limited evidence have yet been available. In this study, we reported responses of soil inorganic nutrients to full factorial N and P treatments in three tropical forests different in initial soil N status (N-saturated old-growth forest and two less-N-rich younger forests). Responses of microbial biomass, annual litterfall production and nutrient input were also monitored. Results showed that N treatments decreased soil inorganic nutrients (except N) in all three forests, but the underlying mechanisms varied depending on forests: through inhibition on litter decomposition in the old-growth forest and through Al(3+) replacement of Ca(2+) in the two younger forests. In contrast, besides great elevation in soil available P, P treatments induced 60%, 50%, 26% increases in sum of exchangeable (K(+)+Ca(2+)+Mg(2+)) in the old-growth and the two younger forests, respectively. These positive effects of P were closely related to P-stimulated microbial biomass and litter nutrient input, implying possible stimulation of nutrient return. Our results suggest that N deposition may result in decreases in soil inorganic nutrients (except N) and that P addition can enhance soil inorganic nutrients to support ecosystem processes in these tropical forests.

Show MeSH