| Records |
| Author |
Lugli, L.F.; Fuchslueger, L.; Vallicrosa, H.; Van Langenhove, L.; Ranits, C.; Garberi, P.R.F.; Verryckt, L.; Grau, O.; Brechet, L.; Peguero, G.; Llusia, J.; Ogaya, R.; Marquez, L.; Portillo-Estrada, M.; Ramirez-Rojas, I.; Courtois, E.; Stahl, C.; Sardans, J.; Penuelas, J.; Verbruggen, E.; Janssens, I. |
| Title |
Contrasting responses of fine root biomass and traits to large-scale nitrogen and phosphorus addition in tropical forests in the Guiana shield |
Type |
A1 Journal article |
Year  |
2024 |
Publication |
Oikos: a journal of ecology |
Abbreviated Journal |
|
| Volume |
2024 |
Issue |
4 |
Pages |
e10412-14 |
| Keywords |
A1 Journal article; Engineering sciences. Technology; Plant and Ecosystems (PLECO) – Ecology in a time of change |
| Abstract |
Fine roots mediate plant nutrient acquisition and growth. Depending on soil nutrient availability, plants can regulate fine root biomass and morphological traits to optimise nutrient acquisition. Little is known, however, about the importance of these parameters influencing forest functioning. In this study, we measured root responses to nutrient additions to gain a mechanistic understanding of plant adaptations to nutrient limitation in two tropical forests in French Guiana, differing twofold in their soil nutrient statuses. We analysed the responses of root biomass, mean root diameter (RD), specific root length (SRL), specific root area (SRA), root tissue density (RTD) and carbon (C), nitrogen (N) and phosphorus (P) concentrations in roots down to 15 cm soil depth after three years of N and P additions. At the lower-fertility site Paracou, no changes in root biomass or morphological traits were detected with either N or P addition, although P concentrations in roots increased with P addition. In the higher fertility site, Nouragues, root biomass and P concentrations in roots increased with P addition, with no changes in morphological traits. In contrast, N addition shifted root traits from acquisitive to more conservative by increasing RTD. A significant interaction between N and P in Nouragues pointed to stronger responses to P addition in the absence of N. Our results suggest that the magnitude and direction of root biomass and trait expression were regulated by soil fertility, corroborated by the response to N or P additions. At low fertility sites, we found lower plasticity in root trait expression compared to more fertile conditions, where N and P additions caused stronger and antagonistic responses. Identifying the exact role of mechanisms affecting root nutrient uptake in Amazon forests growing in different soils will be crucial to foresee if and how rapid global changes can affect their carbon allocation. |
| Address |
|
| Corporate Author |
|
Thesis |
|
| Publisher |
|
Place of Publication |
|
Editor |
|
| Language |
|
Wos |
001142552200001 |
Publication Date |
2024-01-16 |
| Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
| Series Volume |
|
Series Issue |
|
Edition |
|
| ISSN |
0030-1299 |
ISBN |
|
Additional Links |
UA library record; WoS full record |
| Impact Factor |
3.4 |
Times cited |
|
Open Access |
|
| Notes |
|
Approved |
Most recent IF: 3.4; 2024 IF: 4.03 |
| Call Number |
UA @ admin @ c:irua:202834 |
Serial |
9195 |
| Permanent link to this record |
| |
|
| |
| Author |
Ramirez-Rojas, I. |
| Title |
Underground connections : the interplay between tropical rainforest trees and soil microbial communities |
Type |
Doctoral thesis |
| Year |
2024 |
Publication |
|
Abbreviated Journal |
|
| Volume |
|
Issue |
|
Pages |
205 p. |
| Keywords |
Doctoral thesis; Plant and Ecosystems (PLECO) – Ecology in a time of change |
| Abstract |
Tropical rainforests host an exceptional biodiversity and play a fundamental role in the regulation of global climatic cycles. Soil fungi and bacteria are key players in the transformation and processing of nutrients in terrestrial ecosystems while having an essential role as tree mutualists or antagonists. Still, there are gaps in our understanding of the main variables driving soil microbes on these forests and it is unclear how future climate change scenarios may impact soil microbes and further affect the ecosystem. In this thesis, we first explored the drivers of the microbial community composition in two pristine forests in French Guiana by using amplicon DNA sequencing. The neighboring tree species were found to be a crucial factor influencing the fungal and bacterial community composition at our sites regardless of the season. Additionally, within the environmental factors explored, soil moisture, phosphorus (P) and nitrogen (N) availability were consistently the main soil properties controlling the composition of soil microbial communities. Secondly, as increased nutrient deposition due to anthropogenic activities are expected to affect tropical forests ecosystems N and P availability, a factorial N and P nutrient addition experiment in the same sites was used to assess the effects of changes in the soil nutrient stoichiometry on the soil microbial communities. These results showed that after 3 years of nutrient additions, the bacterial and fungal community composition was affected by both the N and P additions. Besides, the fungal community composition had a stronger response to the nutrient addition, especially when P was added. Moreover, when the nutrient addition effect was assessed in bacteria and fungi with different life strategies, we found different nutrient optima between them. Furthermore, to study the effect of the connection to an existing mycorrhizal mycelium on tree seedlings, I established a mycelium exclusion experiment. Interestingly, we could not detect an effect of the mycorrhizal mycelium exclusion on the seedling N uptake, performance, or fungal community composition in roots after one year. All together this work provides a deeper understanding of the factors influencing the soil microbial communities on these lowland tropical forests, demonstrating that the tree community composition exerts a higher influence on the soil microbial community composition than previously expected. Moreover, our results show that the fungal and bacterial community composition and its relationship with trees in the vicinity is highly dependent on the ecosystem nutrient availability. |
| Address |
|
| Corporate Author |
|
Thesis |
|
| Publisher |
|
Place of Publication |
|
Editor |
|
| Language |
|
Wos |
|
Publication Date |
|
| Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
| Series Volume |
|
Series Issue |
|
Edition |
|
| ISSN |
|
ISBN |
|
Additional Links |
UA library record |
| Impact Factor |
|
Times cited |
|
Open Access |
|
| Notes |
|
Approved |
Most recent IF: NA |
| Call Number |
UA @ admin @ c:irua:204907 |
Serial |
9237 |
| Permanent link to this record |
| |
|
| |
| Author |
Vallicrosa, H.; Lugli, L.F.; Fuchslueger, L.; Sardans, J.; Ramirez-Rojas, I.; Verbruggen, E.; Grau, O.; Brechet, L.; Peguero, G.; Van Langenhove, L.; Verryckt, L.T.; Terrer, C.; Llusia, J.; Ogaya, R.; Marquez, L.; Roc-Fernandez, P.; Janssens, I.; Penuelas, J. |
| Title |
Phosphorus scarcity contributes to nitrogen limitation in lowland tropical rainforests |
Type |
A1 Journal article |
| Year |
2023 |
Publication |
Ecology |
Abbreviated Journal |
|
| Volume |
104 |
Issue |
6 |
Pages |
e4049-12 |
| Keywords |
A1 Journal article; Plant and Ecosystems (PLECO) – Ecology in a time of change |
| Abstract |
There is increasing evidence to suggest that soil nutrient availability can limit the carbon sink capacity of forests, a particularly relevant issue considering today's changing climate. This question is especially important in the tropics, where most part of the Earth's plant biomass is stored. To assess whether tropical forest growth is limited by soil nutrients and to explore N and P limitations, we analyzed stem growth and foliar elemental composition of the five stem widest trees per plot at two sites in French Guiana after 3 years of nitrogen (N), phosphorus (P), and N + P addition. We also compared the results between potential N-fixer and non-N-fixer species. We found a positive effect of N fertilization on stem growth and foliar N, as well as a positive effect of P fertilization on stem growth, foliar N, and foliar P. Potential N-fixing species had greater stem growth, greater foliar N, and greater foliar P concentrations than non-N-fixers. In terms of growth, there was a negative interaction between N-fixer status, N + P, and P fertilization, but no interaction with N fertilization. Because N-fixing plants do not show to be completely N saturated, we do not anticipate N providing from N-fixing plants would supply non-N-fixers. Although the soil-age hypothesis only anticipates P limitation in highly weathered systems, our results for stem growth and foliar elemental composition indicate the existence of considerable N and P co-limitation, which is alleviated in N-fixing plants. The evidence suggests that certain mechanisms invest in N to obtain the scarce P through soil phosphatases, which potentially contributes to the N limitation detected by this study. |
| Address |
|
| Corporate Author |
|
Thesis |
|
| Publisher |
|
Place of Publication |
|
Editor |
|
| Language |
|
Wos |
000977760600001 |
Publication Date |
2023-04-11 |
| Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
| Series Volume |
|
Series Issue |
|
Edition |
|
| ISSN |
0012-9658; 1939-9170 |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
| Impact Factor |
4.8 |
Times cited |
|
Open Access |
|
| Notes |
|
Approved |
Most recent IF: 4.8; 2023 IF: 4.809 |
| Call Number |
UA @ admin @ c:irua:196804 |
Serial |
9218 |
| Permanent link to this record |
