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Registro Completo |
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Biblioteca(s): |
Embrapa Florestas. |
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Data corrente: |
06/10/2008 |
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Data da última atualização: |
06/10/2008 |
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Autoria: |
NIWA, S.; KANEKO, N.; OKADA, H.; SAKAMOTO, K. |
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Título: |
Effects of fine-scale simulation of deer browsing on soil microfoodweb structure and N mineralization rate in a temperate forest. |
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Ano de publicação: |
2008 |
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Fonte/Imprenta: |
In: INTERNATIONAL COLLOQUIUM ON SOIL ZOOLOGY, 15; INTERNATIONAL COLLOQUIUM ON APTERYGOTA, 12., 2008, Curitiba. Biodiversity, conservation and sustainabele management of soil animal: abstracts. Colombo: Embrapa Florestas. Editors: George Gardner Brown; Klaus Dieter Sautter; Renato Marques; Amarildo Pasini. 1 CD-ROM. |
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Idioma: |
Inglês |
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Conteúdo: |
In a terrestrial ecosystem, the aboveground and belowground systems depend on each other
for resource supply (nutrient and organic matter). Soil microfauna (protozoa, nematode, etc.) is
considered to play an important role in nitrogen (N) mineralization process by releasing microbial
N. Aboveground herbivory or defoliation on some grass species has found to enhance labile
organic carbon (C) supply from roots and N mineralization in rhizosphere soil in the short term
possibly due to the activation of soil microorganisms and microfauna. To reveal the relationships
between the changes in micro-foodweb (food web with high turnover rate mainly consisting of
microorganisms and microfauna; Lavelle, 1997) structure and N mineralization rate shortly after
aboveground herbivory and the effects of defoliation intensity on N mineralization, we defoliated
a dwarf bamboo (Sasa nipponica)-dominated understory layer in a natural forest at different
intensities to realistically simulate sika deer (Cervus nippon) browsing. Defoliation (0?18% leaf
removal) was performed three times at approximately 1-week intervals in summer. We measured
water-soluble carbon (C) concentration, phospholipid fatty acid (PLFA) profiles as indicators of
microbial community structure, a PLFA of 20:4 as an indicator of protozoan abundance, nematode
community structure at the family level, and the N mineralization rate in 28 days of incubation.
The N mineralization rate in the first 10 days of incubation showed a unimodal response to
defoliation intensity, with a peak mineralization rate at a defoliation rate (number of removed
leaves/total leaves) of 7.6%, correlating with protozoan PLFA and the abundance of Plectidae
(the most dominant family of bacterivorous nematodes). In contrast, the N mineralization rate
during the following 18 days of incubation decreased monotonically with increasing defoliation
intensity, correlating with the water-soluble C concentration in the soil and the C content of new
leaves. These results suggest that removing <15% of leaves may have induced a pulse-like
release of labile organic matter from roots that lasted for less than 1 week and stimulated N
mineralization through microbial loop in soil in the short term (in the first 1?2 weeks after
defoliation). N mineralization, however, was reduced with increase of defoliation intensity in the
longer term (3?5 weeks after defoliation), possibly because of the reduction in labile organic
matter supply from roots 1 week after defoliation. As a result, N mineralization rates over the 28-
day incubation period responded to defoliation intensity in a unimodal pattern with a small peak
(at a defoliation rate of 4.9%) and were negatively affected by high defoliation rates (>10%).
This study suggests that browsing on forest floor plants has significant effects on soil N
mineralization potential through affecting soil micro-foodweb structure and that the effects are
positive or negative depending on browsing intensity level and the length of time that has elapsed
since defoliation. MenosIn a terrestrial ecosystem, the aboveground and belowground systems depend on each other
for resource supply (nutrient and organic matter). Soil microfauna (protozoa, nematode, etc.) is
considered to play an important role in nitrogen (N) mineralization process by releasing microbial
N. Aboveground herbivory or defoliation on some grass species has found to enhance labile
organic carbon (C) supply from roots and N mineralization in rhizosphere soil in the short term
possibly due to the activation of soil microorganisms and microfauna. To reveal the relationships
between the changes in micro-foodweb (food web with high turnover rate mainly consisting of
microorganisms and microfauna; Lavelle, 1997) structure and N mineralization rate shortly after
aboveground herbivory and the effects of defoliation intensity on N mineralization, we defoliated
a dwarf bamboo (Sasa nipponica)-dominated understory layer in a natural forest at different
intensities to realistically simulate sika deer (Cervus nippon) browsing. Defoliation (0?18% leaf
removal) was performed three times at approximately 1-week intervals in summer. We measured
water-soluble carbon (C) concentration, phospholipid fatty acid (PLFA) profiles as indicators of
microbial community structure, a PLFA of 20:4 as an indicator of protozoan abundance, nematode
community structure at the family level, and the N mineralization rate in 28 days of incubation.
The N mineralization rate in the first 10 days of incubation showed a uni... Mostrar Tudo |
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LEADER 03812naa a2200157 a 4500
001 1315056
005 2008-10-06
008 2008 bl uuuu u00u1 u #d
100 1 $aNIWA, S.
245 $aEffects of fine-scale simulation of deer browsing on soil microfoodweb structure and N mineralization rate in a temperate forest.
260 $c2008
520 $aIn a terrestrial ecosystem, the aboveground and belowground systems depend on each other for resource supply (nutrient and organic matter). Soil microfauna (protozoa, nematode, etc.) is considered to play an important role in nitrogen (N) mineralization process by releasing microbial N. Aboveground herbivory or defoliation on some grass species has found to enhance labile organic carbon (C) supply from roots and N mineralization in rhizosphere soil in the short term possibly due to the activation of soil microorganisms and microfauna. To reveal the relationships between the changes in micro-foodweb (food web with high turnover rate mainly consisting of microorganisms and microfauna; Lavelle, 1997) structure and N mineralization rate shortly after aboveground herbivory and the effects of defoliation intensity on N mineralization, we defoliated a dwarf bamboo (Sasa nipponica)-dominated understory layer in a natural forest at different intensities to realistically simulate sika deer (Cervus nippon) browsing. Defoliation (0?18% leaf removal) was performed three times at approximately 1-week intervals in summer. We measured water-soluble carbon (C) concentration, phospholipid fatty acid (PLFA) profiles as indicators of microbial community structure, a PLFA of 20:4 as an indicator of protozoan abundance, nematode community structure at the family level, and the N mineralization rate in 28 days of incubation. The N mineralization rate in the first 10 days of incubation showed a unimodal response to defoliation intensity, with a peak mineralization rate at a defoliation rate (number of removed leaves/total leaves) of 7.6%, correlating with protozoan PLFA and the abundance of Plectidae (the most dominant family of bacterivorous nematodes). In contrast, the N mineralization rate during the following 18 days of incubation decreased monotonically with increasing defoliation intensity, correlating with the water-soluble C concentration in the soil and the C content of new leaves. These results suggest that removing <15% of leaves may have induced a pulse-like release of labile organic matter from roots that lasted for less than 1 week and stimulated N mineralization through microbial loop in soil in the short term (in the first 1?2 weeks after defoliation). N mineralization, however, was reduced with increase of defoliation intensity in the longer term (3?5 weeks after defoliation), possibly because of the reduction in labile organic matter supply from roots 1 week after defoliation. As a result, N mineralization rates over the 28- day incubation period responded to defoliation intensity in a unimodal pattern with a small peak (at a defoliation rate of 4.9%) and were negatively affected by high defoliation rates (>10%). This study suggests that browsing on forest floor plants has significant effects on soil N mineralization potential through affecting soil micro-foodweb structure and that the effects are positive or negative depending on browsing intensity level and the length of time that has elapsed since defoliation.
700 1 $aKANEKO, N.
700 1 $aOKADA, H.
700 1 $aSAKAMOTO, K.
773 $tIn: INTERNATIONAL COLLOQUIUM ON SOIL ZOOLOGY, 15; INTERNATIONAL COLLOQUIUM ON APTERYGOTA, 12., 2008, Curitiba. Biodiversity, conservation and sustainabele management of soil animal: abstracts. Colombo: Embrapa Florestas. Editors: George Gardner Brown; Klaus Dieter Sautter; Renato Marques; Amarildo Pasini. 1 CD-ROM.
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Embrapa Florestas (CNPF) |
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| 2. |  | MAZZOCATO, A. C. Avaliação de progênies de trevo branco na região da Campanha do Rio Grande do Sul. In: CONGRESSO BRASILEIRO DE RECURSOS GENÉTICOS; WORKSHOP EM BIOPROSPECÇÃO E CONSERVAÇÃO DE PLANTAS NATIVAS DO SEMI-ÁRIDO, 3.; WORKSHOP INTERNACIONAL SOBRE BIOENERGIA E MEIO AMBIENTE, 2010, Salvador. Bancos de germoplasma: descobrir a riqueza, garantir o futuro: anais. Brasília, DF: Embrapa Recursos Genéticos e Biotecnologia, 2010. p. 288. 1 CD-ROM. (Embrapa Recursos Genéticos e Biotecnologia. Documentos, 304). PDF 137.| Tipo: Resumo em Anais de Congresso |
| Biblioteca(s): Embrapa Pecuária Sul. |
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| 3. | | MAZZOCATO, A. C. Herbário CNPO da Embrapa Pecuária Sul. In: WORKSHOP DE CURADORES DE GERMOPLASMA DO BRASIL, 2011, Campinas. Anais [e] resumos dos trabalhos. Brasília, DF: Embrapa Recursos Genéticos e Biotecnologia, 2011. p. 327.| Tipo: Resumo em Anais de Congresso |
| Biblioteca(s): Embrapa Pecuária Sul. |
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| Registros recuperados : 150 | |
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