1
|
Brunn M, Hafner BD, Zwetsloot MJ, Weikl F, Pritsch K, Hikino K, Ruehr NK, Sayer EJ, Bauerle TL. Carbon allocation to root exudates is maintained in mature temperate tree species under drought. New Phytol 2022; 235:965-977. [PMID: 35403713 DOI: 10.1111/nph.18157] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/06/2021] [Accepted: 04/04/2022] [Indexed: 06/14/2023]
Abstract
Carbon (C) exuded via roots is proposed to increase under drought and facilitate important ecosystem functions. However, it is unknown how exudate quantities relate to the total C budget of a drought-stressed tree, that is, how much of net-C assimilation is allocated to exudation at the tree level. We calculated the proportion of daily C assimilation allocated to root exudation during early summer by collecting root exudates from mature Fagus sylvatica and Picea abies exposed to experimental drought, and combining above- and belowground C fluxes with leaf, stem and fine-root surface area. Exudation from individual roots increased exponentially with decreasing soil moisture, with the highest increase at the wilting point. Despite c. 50% reduced C assimilation under drought, exudation from fine-root systems was maintained and trees exuded 1.0% (F. sylvatica) to 2.5% (P. abies) of net C into the rhizosphere, increasing the proportion of C allocation to exudates two- to three-fold. Water-limited P. abies released two-thirds of its exudate C into the surface soil, whereas in droughted F. sylvatica it was only one-third. Across the entire root system, droughted trees maintained exudation similar to controls, suggesting drought-imposed belowground C investment, which could be beneficial for ecosystem resilience.
Collapse
Affiliation(s)
- Melanie Brunn
- iES Landau, Institute for Environmental Sciences, University of Koblenz-Landau, 76829, Landau, Germany
| | - Benjamin D Hafner
- School of Integrative Plant Science, Cornell University, Ithaca, NY, 14853, USA
| | - Marie J Zwetsloot
- Soil Biology Group, Wageningen University, 6708 PB, Wageningen, the Netherlands
| | - Fabian Weikl
- Institute of Biochemical Plant Pathology, Helmholtz Zentrum München GmbH - German Research Center for Environmental Health, 85764, Neuherberg, Germany
- TUM School of Life Sciences, Land Surface-Atmosphere Interactions, Ecophysiology of Plants, Technical University of Munich, 85354, Freising, Germany
| | - Karin Pritsch
- Institute of Biochemical Plant Pathology, Helmholtz Zentrum München GmbH - German Research Center for Environmental Health, 85764, Neuherberg, Germany
| | - Kyohsuke Hikino
- TUM School of Life Sciences, Land Surface-Atmosphere Interactions, Ecophysiology of Plants, Technical University of Munich, 85354, Freising, Germany
| | - Nadine K Ruehr
- Institute of Meteorology and Climate Research - Atmospheric Environmental Research (IMK-IFU), Karlsruhe Institute of Technology (KIT), 82467, Garmisch-Partenkirchen, Germany
| | - Emma J Sayer
- Lancaster Environment Centre, Lancaster University, LA1 4YQ, Lancaster, UK
| | - Taryn L Bauerle
- School of Integrative Plant Science, Cornell University, Ithaca, NY, 14853, USA
| |
Collapse
|
2
|
Harvey CA, Pritts AA, Zwetsloot MJ, Jansen K, Pulleman MM, Armbrecht I, Avelino J, Barrera JF, Bunn C, García JH, Isaza C, Munoz-Ucros J, Pérez-Alemán CJ, Rahn E, Robiglio V, Somarriba E, Valencia V. Transformation of coffee-growing landscapes across Latin America. A review. Agron Sustain Dev 2021; 41:62. [PMID: 34484434 PMCID: PMC8406019 DOI: 10.1007/s13593-021-00712-0] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Accepted: 06/28/2021] [Indexed: 06/01/2023]
Abstract
UNLABELLED In Latin America, the cultivation of Arabica coffee (Coffea arabica) plays a critical role in rural livelihoods, biodiversity conservation, and sustainable development. Over the last 20 years, coffee farms and landscapes across the region have undergone rapid and profound biophysical changes in response to low coffee prices, changing climatic conditions, severe plant pathogen outbreaks, and other drivers. Although these biophysical transformations are pervasive and affect millions of rural livelihoods, there is limited information on the types, location, and extent of landscape changes and their socioeconomic and ecological consequences. Here we review the state of knowledge on the ongoing biophysical changes in coffee-growing regions, explore the potential socioeconomic and ecological impacts of these changes, and highlight key research gaps. We identify seven major land-use trends which are affecting the sustainability of coffee-growing regions across Latin America in different ways. These trends include (1) the widespread shift to disease-resistant cultivars, (2) the conventional intensification of coffee management with greater planting densities, greater use of agrochemicals and less shade, (3) the conversion of coffee to other agricultural land uses, (4) the introduction of Robusta coffee (Coffea canephora) into areas not previously cultivated with coffee, (5) the expansion of coffee into forested areas, (6) the urbanization of coffee landscapes, and (7) the increase in the area of coffee produced under voluntary sustainability standards. Our review highlights the incomplete and scattered information on the drivers, patterns, and outcomes of biophysical changes in coffee landscapes, and lays out a detailed research agenda to address these research gaps and elucidate the effects of different landscape trajectories on rural livelihoods, biodiversity conservation, and other aspects of sustainable development. A better understanding of the drivers, patterns, and consequences of changes in coffee landscapes is vital for informing the design of policies, programs, and incentives for sustainable coffee production. SUPPLEMENTARY INFORMATION The online version contains supplementary material available at 10.1007/s13593-021-00712-0.
Collapse
Affiliation(s)
- Celia A. Harvey
- Monteverde Institute, Apdo.69-5655, Monteverde, Puntarenas, Costa Rica
| | - Alyssa A. Pritts
- Farming Systems Ecology Group, Wageningen University & Research, P.O. Box 430, 6700 AK Wageningen, The Netherlands
| | - Marie J. Zwetsloot
- Soil Biology Group, Wageningen University & Research, P.O. Box 47, 6700 AA Wageningen, The Netherlands
| | - Kees Jansen
- Rural Sociology Group, Wageningen University & Research, Hollandseweg 1, 6706 KN Wageningen, The Netherlands
| | - Mirjam M. Pulleman
- Soil Biology Group, Wageningen University & Research, P.O. Box 47, 6700 AA Wageningen, The Netherlands
- The International Center for Tropical Agriculture (CIAT), Km 17 Recta Cali-Palmira, AA 6713, 763537 Cali, Colombia
| | - Inge Armbrecht
- Departamento de Biología, Universidad del Valle, Calle 13 # 100-00 ed, 320 Cali, Colombia
| | - Jacques Avelino
- CIRAD, UMR PHIM, San José, Costa Rica
- PHIM, Univ Montpellier, CIRAD, INRAE, Institut Agro, IRD, Montpellier, France
- Program of Agriculture, Livestock and Agroforestry, CATIE, Turrialba, 7170 Costa Rica
- IICA, 2200 Coronado, San José, AP 55 Costa Rica
| | - Juan F. Barrera
- Arthropod Ecology and Pest Management Group, Department of Agriculture, Society and Environment, El Colegio de la Frontera Sur, Carretera Antiguo Aeropuerto km 2.5, 30700 Tapachula, Chiapas Mexico
| | - Christian Bunn
- The International Center for Tropical Agriculture (CIAT), Km 17 Recta Cali-Palmira, AA 6713, 763537 Cali, Colombia
- University of Göttingen, Platz der Göttinger Sieben 5, 37073 Göttingen, Germany
| | - Javier Hoyos García
- Parque Tecnológico de Innovación TECNiCAFÉ, Cra 17 # 48 N 18 Casa 53 Conjunto Cerrado Entrepinos, Popayán, Cauca Colombia
| | - Carlos Isaza
- Programa de Café para Solidaridad en Colombia, Solidaridad, Calle 43 N, °23-78 Manizales, Colombia
| | - Juana Munoz-Ucros
- School of Integrative Plant Science, Cornell University, 236 Tower Rd, Ithaca, NY USA
| | - Carlos J. Pérez-Alemán
- Fundación Solidaridad Latinoamericana, Calle Evelio Lara No. 131-B, Ciudad del Saber, Ciudad de Panamá, Panamá
| | - Eric Rahn
- The International Center for Tropical Agriculture (CIAT), Km 17 Recta Cali-Palmira, AA 6713, 763537 Cali, Colombia
| | - Valentina Robiglio
- World Agroforestry Centre (ICRAF), c/o CIP, Av. La Molina 1895, P.O Box 1558, 12 Lima, Peru
| | - Eduardo Somarriba
- Program of Agriculture, Livestock and Agroforestry, CATIE, Turrialba, 7170 Costa Rica
| | - Vivian Valencia
- Farming Systems Ecology Group, Wageningen University & Research, P.O. Box 430, 6700 AK Wageningen, The Netherlands
| |
Collapse
|
3
|
Zwetsloot MJ, Bauerle TL. Repetitive seasonal drought causes substantial species-specific shifts in fine-root longevity and spatio-temporal production patterns in mature temperate forest trees. New Phytol 2021; 231:974-986. [PMID: 33908081 DOI: 10.1111/nph.17432] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/23/2020] [Accepted: 04/15/2021] [Indexed: 06/12/2023]
Abstract
Temperate forest ecosystems are exposed to a higher frequency, duration and severity of drought. To promote forest longevity in a changing climate, we require a better understanding of the long-term impacts of repetitive drought events on fine-root dynamics in mature forests. Using minirhizotron methods, we investigated the effect of seasonal drought on fine-root dynamics in single-species and mixed-species arrangements of Fagus sylvatica (European beech) and Picea abies (Norway spruce) by means of a 4-yr-long throughfall-exclusion experiment. Fine-root production of both species decreased under drought. However, this reduction was not evident for P. abies when grown intermixed with F. sylvatica. Throughfall-exclusion prolonged the lifespan of P. abies roots but did not change the lifespan of F. sylvatica roots, except in 2016. Fagus sylvatica responded to drought by reducing fine-root production at specific depths and during roof closure. This is the first study to examine long-term trends in mature forest fine-root dynamics under repetitive drought events. Species-specific fine-root responses to drought have implications for the rate and depth of root-derived organic matter supply to soil. From a root dynamics perspective, intermixing tree species is not beneficial to all species but dampens drought impacts on the belowground productivity of P. abies.
Collapse
Affiliation(s)
- Marie J Zwetsloot
- School of Integrative Plant Science, Cornell University, Ithaca, NY, 14850, USA
| | - Taryn L Bauerle
- School of Integrative Plant Science, Cornell University, Ithaca, NY, 14850, USA
| |
Collapse
|
5
|
Zwetsloot MJ, Goebel M, Paya A, Grams TEE, Bauerle TL. Specific spatio-temporal dynamics of absorptive fine roots in response to neighbor species identity in a mixed beech-spruce forest. Tree Physiol 2019; 39:1867-1879. [PMID: 31504991 DOI: 10.1093/treephys/tpz086] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/25/2019] [Revised: 06/07/2019] [Accepted: 07/18/2019] [Indexed: 06/10/2023]
Abstract
Absorptive fine roots are an important driver of soil biogeochemical cycles. Yet, the spatio-temporal dynamics of those roots in the presence of neighboring species remain poorly understood. The aim of this study was to analyze shifts in absorptive fine-root traits in monoculture or mixtures of Fagus sylvatica [L.] and Picea abies [L.] Karst. We hypothesized that root competition would be higher under single-species than mixed-species interactions, leading to changes in (i) root survivorship, diameter and respiration and (ii) spatio-temporal patterns of root growth and death. Using minirhizotron methods, we monitored the timing and location of absorptive fine-root growth and death at an experimental forest in southern Germany from 2011 to 2013. We also measured root respiration in the spring and fall seasons of 2012 and 2013. Our findings show that the absorptive fine roots of F. sylvatica had a 50% higher risk of root mortality and higher respiration rates in the single-species compared to mixed-species zones. These results support our hypothesis that root competition is less intense for F. sylvatica in mixture versus monoculture. We were unable to find confirmation for the same hypothesis for P. abies. To analyze spatio-temporal patterns of absorptive fine-root production and mortality, we used a mixed-effects model considering root depth (space) and seasons (time) simultaneously. This analysis showed that F. sylvatica shifts root production towards shallower soil layers in mixed-species stands, besides significant seasonal fluctuations in root production depths for both species. Ultimately, the impact of neighbor species identity on root traits observed in this study has important implications for where, when and how fast root-facilitated carbon cycling takes place in single-species versus mixed-species forests. In addition, our study highlights the need for inclusion of absorptive fine-root spatio-temporal dynamics when examining belowground plant interactions and biogeochemical cycles.
Collapse
Affiliation(s)
- Marie J Zwetsloot
- School of Integrative Plant Science, Cornell University, 236 Tower Road, Ithaca, NY 14853, USA
- Soil Biology Group, Wageningen University, Droevendaalsesteeg 3, 6708 PB Wageningen, the Netherlands
| | - Marc Goebel
- Department of Natural Resources, Cornell University, 111 Fernow Hall, Ithaca, NY 14853, USA
| | - Alex Paya
- School of Integrative Plant Science, Cornell University, 236 Tower Road, Ithaca, NY 14853, USA
| | - Thorsten E E Grams
- Ecophysiology of Plants, Technical University of Munich, Am Hochanger 13, 85354 Freising, Germany
| | - Taryn L Bauerle
- School of Integrative Plant Science, Cornell University, 236 Tower Road, Ithaca, NY 14853, USA
| |
Collapse
|
6
|
Zwetsloot MJ, Kessler A, Bauerle TL. Phenolic root exudate and tissue compounds vary widely among temperate forest tree species and have contrasting effects on soil microbial respiration. New Phytol 2018; 218:530-541. [PMID: 29473651 DOI: 10.1111/nph.15041] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/25/2017] [Accepted: 01/10/2018] [Indexed: 06/08/2023]
Abstract
Root-soil interactions fundamentally affect the terrestrial carbon (C) cycle and thereby ecosystem feedbacks to climate change. This study addressed the question of whether the secondary metabolism of different temperate forest tree species can affect soil microbial respiration. We hypothesized that phenolics can both increase and decrease respiration depending on their function as food source, mobilizer of other soil resources, signaling compound, or toxin. We analyzed the phenolic compounds from root exudates and root tissue extracts of six tree species grown in a glasshouse using high-performance liquid chromatography. We then tested the effect of individual phenolic compounds, representing the major identified phenylpropanoid compound classes, on microbial respiration through a 5-d soil incubation. Phenolic root profiles were highly species-specific. Of the eight classes identified, flavonoids were the most abundant, with flavanols being the predominating sub-class. Phenolic effects on microbial respiration ranged from a 26% decrease to a 46% increase, with reduced respiration occurring in the presence of compounds possessing a catechol ring. Tree species variation in root phenolic composition influences the magnitude and direction of root effects on microbial respiration. Our data support the hypothesis that functional group rather than biosynthetic class determines the root phenolic effect on soil C cycling.
Collapse
Affiliation(s)
- Marie J Zwetsloot
- School of Integrative Plant Science, Cornell University, Ithaca, NY, 14850, USA
| | - André Kessler
- Department of Ecology and Evolutionary Biology, Cornell University, Ithaca, NY, 14850, USA
| | - Taryn L Bauerle
- School of Integrative Plant Science, Cornell University, Ithaca, NY, 14850, USA
| |
Collapse
|
7
|
Zwetsloot MJ, Lehmann J, Solomon D. Recycling slaughterhouse waste into fertilizer: how do pyrolysis temperature and biomass additions affect phosphorus availability and chemistry? J Sci Food Agric 2015; 95:281-288. [PMID: 24789609 DOI: 10.1002/jsfa.6716] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/07/2014] [Revised: 03/27/2014] [Accepted: 04/24/2014] [Indexed: 06/03/2023]
Abstract
BACKGROUND Pyrolysis of slaughterhouse waste could promote more sustainable phosphorus (P) usage through the development of alternative P fertilizers. This study investigated how pyrolysis temperature (220, 350, 550 and 750 °C), rendering before pyrolysis, and wood or corn biomass additions affect P chemistry in bone char, plant availability, and its potential as P fertilizer. RESULTS Linear combination fitting of synchrotron-based X-ray absorption near edge structure spectra demonstrated that higher pyrolysis temperatures decreased the fit with organic P references, but increased the fit with a hydroxyapatite (HA) reference, used as an indicator of high calcium phosphate (CaP) crystallinity. The fit to the HA reference increased from 0% to 69% in bone with meat residue and from 20% to 95% in rendered bone. Biomass additions to the bone with meat residue reduced the fit to the HA reference by 83% for wood and 95% for corn, and additions to rendered bone by 37% for wood. No detectable aromatic P forms were generated by pyrolysis. High CaP crystallinity was correlated with low water-extractable P, but high formic acid-extractable P indicative of high plant availability. Bone char supplied available P which was only 24% lower than Triple Superphosphate fertilizer and two- to five-fold higher than rock phosphate. CONCLUSION Pyrolysis temperature and biomass additions can be used to design P fertilizer characteristics of bone char through changing CaP crystallinity that optimize P availability to plants.
Collapse
Affiliation(s)
- Marie J Zwetsloot
- Department of Crop and Soil Sciences, Cornell University, NY 14853, USA
| | | | | |
Collapse
|