Droevendaalsesteeg 10
6708 PB Wageningen
The Netherlands
As an ecologist I am trained to unravel the complex web of interactions that shape natural and agro-ecosystems.
Jasper Wubs obtained his MSc (2010) from Utrecht University and PhD (2017) degree at Wageningen University (the Netherlands), where he has been studying plant-soil biota interactions and how they steer natural plant community dynamics and their use in nature restoration (with Prof. Martijn Bezemer and Prof. Wim van der Putten).
He then obtained an NWO Rubicon (2018; ETH Zurich) grant to study how soil microbiomes can be used to improve soil restoration in degraded arable soils in the central Kenyan highlands (with Prof. Johan Six and Dr. Martin Hartmann).
In 2021 Jasper returned to the Netherlands to coordinate data collection and analysis within the new IJkcentrum voor de Bodem (https://nioo.knaw.nl/nl/ijkcentrumbodem) as part of the Onder het Maaiveld (https://onder-het-maaiveld.nl/) project (with IUCN, Vlinderstichting, WUR, Centre for Soil Ecology). The project aims to map and benchmark the soil biodiversity of the Netherlands to provide action perspectives for land managers.
Recently, Jasper received a EU MSCA Postdoctoral Fellowship to study soil multifunctionality in relation to the stoichiometry of plants, microbes and soils (MultiSol) at NIOO.
The potential for soil microbiomes to assist in the restoration of biological, chemical and physical soil degradation is tremendous, yet very few projects use the whole-microbiome approach. This is potentially an important research gap, because in-situ interactions among members of the microbiome do fundamentally alter the functioning of specific biota and thus the soils they are in.
Air is a major conduit for the dispersal of organisms at the local and the global scale. Most research has focused on the dispersal of plants, vertebrates and human disease agents. However, the air represents a key dispersal medium also for bacteria, fungi and protists. Many of those represent potential pathogens of animals and plants and have until now gone largely unrecorded. Here we studied the turnover in composition of the entire aerobiome, the collective diversity of airborne microorganisms. For that we performed daily analyses of all prokaryotes and eukaryotes (including plants) using multi-marker high-throughput sequencing for a total of three weeks. We linked the resulting communities to local weather conditions, to assess determinants of aerobiome composition and distribution. We observed hundreds of microbial taxa, mostly belonging to spore-forming organisms including fungi, but also protists. Additionally, we detected many potential human- and plant-pathogens. Community composition fluctuated on a daily basis and was linked to concurrent weather conditions, particularly air pressure and temperature. Using network analyses, we identified taxonomically diverse groups of organisms with correlated temporal dynamics. In part, this was due to co-variation with environmental conditions, while we could also detect specific host-parasite interactions. This study provides the first full inventory of the aerobiome and identifies putative drivers of its dynamics in terms of taxon composition. This knowledge can help develop early warning systems against pathogens and improve our understanding of microbial dispersal.
Interactions between aboveground and belowground organisms are important drivers of plant growth and performance in natural ecosystems. Making practical use of such above-belowground biotic interactions offers important opportunities for enhancing the sustainability of agriculture, as it could favor crop growth, nutrient supply, and defense against biotic and abiotic stresses. However, the operation of above-and belowground organisms at different spatial and temporal scales provides important challenges for application in agriculture. Aboveground organisms, such as herbivores and pollinators, operate at spatial scales that exceed individual fields and are highly variable in abundance within growing seasons. In contrast, pathogenic, symbiotic, and decomposer soil biota operate at more localized spatial scales from individual plants to patches of square meters, however, they generate legacy effects on plant performance that may last from single to multiple years. The challenge is to promote pollinators and suppress pests at the landscape and field scale, while creating positive legacy effects of local plant-soil interactions for next generations of plants. Here, we explore the possibilities to improve utilization of above-belowground interactions in agro-ecosystems by considering spatio-temporal scales at which aboveground and belowground organisms operate. We identified that successful integration of above-belowground biotic interactions initially requires developing crop rotations and intercropping systems that create positive local soil legacy effects for neighboring as well subsequent crops. These configurations may then be used as building blocks to design landscapes that accommodate beneficial aboveground communities with respect to their required resources. For successful adoption of above-belowground interactions in agriculture there is a need for context-specific solutions, as well as sound socio-economic embedding.
Plant–soil feedback (PSF) has been identified as a key driver of local plant diversity and evenness in competitive communities. However, while it has been shown that spatial PSF heterogeneity can alter plant performance and competitive interactions, there is no proof of principle that spatial PSF heterogeneity enhances community diversity. Using a grassland model system, we separated two aspects of spatial heterogeneity: the number of species conditioning the soil and spatial distribution of the PSFs. Our data show that PSFs promoted a higher plant evenness when the soil was conditioned by multiple species (mixed-conditioned) than when the soil was conditioned by a single species (mono-conditioned). On mono-conditioned soils, heterospecifics typically outperformed the focal species. In addition, there was a trend for increasing community evenness from uniform, via fine-grained to coarse-grained mixed-conditioned soils, but this was not significant. On mixed-conditioned soils, performance of all competing species was intermediate to the best and the worst mono-conditioned soils, leading to higher community evenness. Our data demonstrate that PSFs play a role in promoting plant evenness. Across mono-conditioned soils, PSF led to altered competitive hierarchies. However, on soils conditioned by multiple species, competitive ability among species was more similar and this led to higher plant evenness. The spatial distribution of the heterogeneity, on the other hand, did not significantly affect plant evenness. Our data therefore show that community evenness was more strongly related to the number of plant species that conditioned the soil than the spatial distribution of the PSF heterogeneity. Future studies need to investigate the importance of PSFs in the field across plant life stages and multiple generations. A plain language summary is available for this article.
Background and Aims Populations established by long-distance colonization are expected to show low levels of genetic variation per population, but strong genetic differentiation among populations. Whether isolated populations indeed show this genetic signature of isolation depends on the amount and diversity of diaspores arriving by long-distance dispersal, and time since colonization. For ferns, however, reliable estimates of long-distance dispersal rates remain largely unknown, and previous studies on fern population genetics often sampled older or non-isolated populations. Young populations in recent, disjunct habitats form a useful study system to improve our understanding of the genetic impact of long-distance dispersal. Methods Microsatellite markers were used to analyse the amount and distribution of genetic diversity in young populations of four widespread calcicole ferns (Asplenium scolopendrium, diploid; Asplenium trichomanes subsp. quadrivalens, tetraploid; Polystichum setiferum, diploid; and Polystichum aculeatum, tetraploid), which are rare in The Netherlands but established multiple populations in a forest (the Kuinderbos) on recently reclaimed Dutch polder land following long-distance dispersal. Reference samples from populations throughout Europe were used to assess how much of the existing variation was already present in the Kuinderbos. Key Results A large part of the Dutch and European genetic diversity in all four species was already found in the Kuinderbos. This diversity was strongly partitioned among populations. Most populations showed low genetic variation and high inbreeding coefficients, and were assigned to single, unique gene pools in cluster analyses. Evidence for interpopulational gene flow was low, except for the most abundant species. Conclusions The results show that all four species, diploids as well as polyploids, were capable of frequent long-distance colonization via single-spore establishment. This indicates that even isolated habitats receive dense and diverse spore rains, including genotypes capable of self-fertilization. Limited gene flow may conserve the genetic signature of multiple long-distance colonization events for several decades.
Background
Many soils in sub-Saharan Africa (SSA) have been chemically, physically and biologically degraded. As a result an estimated 50% of agricultural soils do not increase productivity in response to mineral fertiliser addition, so called non-responsive soils. These soils can be restored using Integrated Soil Fertility Management (ISFM), but this requires substantial amounts of organic substrates (e.g. manure) to be added to the soil for many years. Many farmers in SSA do not possess these kinds of resources.
Plants, including crops, grow in tight associations with their specific soil microbiomes – the collective diversity of bacteria, archaea, fungi, protists, and other microorganisms found in soil. The soil microbiome can induce enhanced plant functioning, including improved nutrient acquisition, plant defence and tolerance of abiotic stresses, particularly when introduced as consortia of species. In this project we investigate to what extent naturally occurring microbiomes in Kenya can assist crop growth, and we test to what extend the can help maize crops to grow under progressively lower organic substrate inputs into the soil.
Objectives
This empirical study will combine modern high-throughput DNA sequencing methods and controlled greenhouse cultivations to explore the relationship between Kenyan maize crops and the natural diversity of soil microbiomes.
• Provide the first assessment of soil microbiome diversity in SSA in a range of representative soil types as well as agricultural and natural systems. Despite several, global assessments of soil biodiversity, the vast majority of the 11.7 million square mile continent remains completely unstudied.
• Screen the potential of naturally occurring soil microbiomes to improve the performance of maize crops.
• Use host-mediated selection to engineer microbiomes with improved function and assess to what extent organic substrate inputs can be reduced while still building soil fertility in conjunction with these engineered microbiomes.
Outcomes
This study will provide the first inventory of the functional capabilities of natural soil microbiomes to improve maize crop production in a tropical farming system. Using host mediated selection we will study to what extend microbiomes functioning can be optimized using low-tech methods. In particular we would like to test if engineered microbiomes can cope with progressively lower organic substrate inputs. Furthermore, the project will substantially expand the global dataset of African soil biodiversity.
Jasper actively takes his research out of academia and to practitioners, policy makers and the general public. For this work he received the 2016 Parnassia Award from the Radboud University Nijmegen.
Publications for practitioners (in Dutch)
Wubs ERJ, Van der Putten WH, Bosch M, Bezemer TM. 2016. Natuurherstel door grondtransplantatie. Landschap 33(1): 11-14.
Van Noppen F, Bosch M, Wubs ERJ, Haanstra L, Verbaan W, Van Houwelingen D, Philippona J, Van Ekeris R, Van der Putten WH, Bezemer TM. 2015. Afgraven, bodemtransplantaties en uitstrooien van maaisel op voormalige landbouwgronden: het Reijerscamp experiment. De Levende Natuur 116: 222-227.
Media attention
TV and radio interviews and documentaries
Radio: NPO Radio 1 Vroege Vogels. Bodemtransplantaties helpen heideherstel. 20-08-2017
Radio: BNR Wetenschap. Bodembeestjestransplantatie herstelt de natuur. 3-7-2016.
TV: SAT3/nano (ZDF, Germany), theme episode about soil life. 03-09-2014.
Articles in Popular Press: NRC Handelsblad, NRC Next, Der Tagesspiegel, Scientist, The Scientist, Popular Science, Der Standard, Neue Züricher Zeitung, Potsdamer Neueste Nachrichten.