Limits...
A closeup study of early beech litter decomposition: potential drivers and microbial interactions on a changing substrate.

Brandstätter C, Keiblinger K, Wanek W, Zechmeister-Boltenstern S - Plant Soil (2013)

Bottom Line: At the beginning of the experiment microbial biomass increased and pools of inorganic nitrogen (N) decreased, followed by an increase in fungal PLFAs.The C:N ratio of the dissolved pool, rather than the quantity of N, was the major driver of decomposition rates.We saw dynamic changes in the microbial community from the beginning through the termination of the experiment.

View Article: PubMed Central - PubMed

Affiliation: BFW - Federal Research and Training Centre for Forests, Natural Hazards and Landscape, Seckendorff-Gudent Weg 8, 1131 Vienna, Austria ; Institute for Water Quality, Resources and Waste Management, Vienna University of Technology, Karlsplatz 13/226, 1040 Vienna, Austria.

ABSTRACT

Aims: Litter decomposition and subsequent nutrient release play a major role in forest carbon and nutrient cycling. To elucidate how soluble or bulk nutrient ratios affect the decomposition process of beech (Fagus sylvatica L.) litter, we conducted a microcosm experiment over an 8 week period. Specifically, we investigated leaf-litter from four Austrian forested sites, which varied in elemental composition (C:N:P ratio). Our aim was to gain a mechanistic understanding of early decomposition processes and to determine microbial community changes.

Methods: We measured initial litter chemistry, microbial activity in terms of respiration (CO2), litter mass loss, microbial biomass C and N (Cmic and Nmic), non purgeable organic carbon (NPOC), total dissolved nitrogen (TDN), NH4 (+), NO3 (-) and microbial community composition (phospholipid fatty acids - PLFAs).

Results: At the beginning of the experiment microbial biomass increased and pools of inorganic nitrogen (N) decreased, followed by an increase in fungal PLFAs. Sites higher in NPOC:TDN (C:N of non purgeable organic C and total dissolved N), K and Mn showed higher respiration.

Conclusions: The C:N ratio of the dissolved pool, rather than the quantity of N, was the major driver of decomposition rates. We saw dynamic changes in the microbial community from the beginning through the termination of the experiment.

No MeSH data available.


Related in: MedlinePlus

Time course of a) non-purgeable organic carbon (NPOC) b) total dissolved nitrogen (TDN), c) ratio of NPOC and TDN (NPOC:TDN). The remaining graph d) represents a quadratic regression between TDN and the cumulative litter mass loss (ML). The values for TDN between b) and d) differ, since the first week was not used for mass loss determination. The outer lines of the regression curves indicate a 95 % confidence interval and the line in between is the regression line. An ANOVA was conducted for week 4 and 8 to detect significant differences between the four sites. (ns p > 0.5; * p < 0.05; ** p < 0.01; *** p < 0.001). AK Achenkirch, KL Klausen-Leopoldsdorf, OR Ort, PE Perg
© Copyright Policy - OpenAccess
Related In: Results  -  Collection


getmorefigures.php?uid=PMC4372839&req=5

Fig2: Time course of a) non-purgeable organic carbon (NPOC) b) total dissolved nitrogen (TDN), c) ratio of NPOC and TDN (NPOC:TDN). The remaining graph d) represents a quadratic regression between TDN and the cumulative litter mass loss (ML). The values for TDN between b) and d) differ, since the first week was not used for mass loss determination. The outer lines of the regression curves indicate a 95 % confidence interval and the line in between is the regression line. An ANOVA was conducted for week 4 and 8 to detect significant differences between the four sites. (ns p > 0.5; * p < 0.05; ** p < 0.01; *** p < 0.001). AK Achenkirch, KL Klausen-Leopoldsdorf, OR Ort, PE Perg

Mentions: Non purgeable organic C and total dissolved N (NPOC and TDN, Table 2, Fig. 2a and b) decreased over time, with significant differences between litters from different sites at week four and eight. A strong positive relation between NPOC and TDN was observed by single linear regression analysis (p < 0.001, r2 = 0.78). The time course of NPOC was similar to that of TDN, except that TDN was highest for KL and lowest for AK most of the time. The C:N ratio of non purgeable organic C and total dissolved N (NPOC:TDN) increased between start and end of the experiment for all sites, and its time course is shown in Fig. 2c.Fig. 2


A closeup study of early beech litter decomposition: potential drivers and microbial interactions on a changing substrate.

Brandstätter C, Keiblinger K, Wanek W, Zechmeister-Boltenstern S - Plant Soil (2013)

Time course of a) non-purgeable organic carbon (NPOC) b) total dissolved nitrogen (TDN), c) ratio of NPOC and TDN (NPOC:TDN). The remaining graph d) represents a quadratic regression between TDN and the cumulative litter mass loss (ML). The values for TDN between b) and d) differ, since the first week was not used for mass loss determination. The outer lines of the regression curves indicate a 95 % confidence interval and the line in between is the regression line. An ANOVA was conducted for week 4 and 8 to detect significant differences between the four sites. (ns p > 0.5; * p < 0.05; ** p < 0.01; *** p < 0.001). AK Achenkirch, KL Klausen-Leopoldsdorf, OR Ort, PE Perg
© Copyright Policy - OpenAccess
Related In: Results  -  Collection

Show All Figures
getmorefigures.php?uid=PMC4372839&req=5

Fig2: Time course of a) non-purgeable organic carbon (NPOC) b) total dissolved nitrogen (TDN), c) ratio of NPOC and TDN (NPOC:TDN). The remaining graph d) represents a quadratic regression between TDN and the cumulative litter mass loss (ML). The values for TDN between b) and d) differ, since the first week was not used for mass loss determination. The outer lines of the regression curves indicate a 95 % confidence interval and the line in between is the regression line. An ANOVA was conducted for week 4 and 8 to detect significant differences between the four sites. (ns p > 0.5; * p < 0.05; ** p < 0.01; *** p < 0.001). AK Achenkirch, KL Klausen-Leopoldsdorf, OR Ort, PE Perg
Mentions: Non purgeable organic C and total dissolved N (NPOC and TDN, Table 2, Fig. 2a and b) decreased over time, with significant differences between litters from different sites at week four and eight. A strong positive relation between NPOC and TDN was observed by single linear regression analysis (p < 0.001, r2 = 0.78). The time course of NPOC was similar to that of TDN, except that TDN was highest for KL and lowest for AK most of the time. The C:N ratio of non purgeable organic C and total dissolved N (NPOC:TDN) increased between start and end of the experiment for all sites, and its time course is shown in Fig. 2c.Fig. 2

Bottom Line: At the beginning of the experiment microbial biomass increased and pools of inorganic nitrogen (N) decreased, followed by an increase in fungal PLFAs.The C:N ratio of the dissolved pool, rather than the quantity of N, was the major driver of decomposition rates.We saw dynamic changes in the microbial community from the beginning through the termination of the experiment.

View Article: PubMed Central - PubMed

Affiliation: BFW - Federal Research and Training Centre for Forests, Natural Hazards and Landscape, Seckendorff-Gudent Weg 8, 1131 Vienna, Austria ; Institute for Water Quality, Resources and Waste Management, Vienna University of Technology, Karlsplatz 13/226, 1040 Vienna, Austria.

ABSTRACT

Aims: Litter decomposition and subsequent nutrient release play a major role in forest carbon and nutrient cycling. To elucidate how soluble or bulk nutrient ratios affect the decomposition process of beech (Fagus sylvatica L.) litter, we conducted a microcosm experiment over an 8 week period. Specifically, we investigated leaf-litter from four Austrian forested sites, which varied in elemental composition (C:N:P ratio). Our aim was to gain a mechanistic understanding of early decomposition processes and to determine microbial community changes.

Methods: We measured initial litter chemistry, microbial activity in terms of respiration (CO2), litter mass loss, microbial biomass C and N (Cmic and Nmic), non purgeable organic carbon (NPOC), total dissolved nitrogen (TDN), NH4 (+), NO3 (-) and microbial community composition (phospholipid fatty acids - PLFAs).

Results: At the beginning of the experiment microbial biomass increased and pools of inorganic nitrogen (N) decreased, followed by an increase in fungal PLFAs. Sites higher in NPOC:TDN (C:N of non purgeable organic C and total dissolved N), K and Mn showed higher respiration.

Conclusions: The C:N ratio of the dissolved pool, rather than the quantity of N, was the major driver of decomposition rates. We saw dynamic changes in the microbial community from the beginning through the termination of the experiment.

No MeSH data available.


Related in: MedlinePlus