Ammonium as a Driving Force of Plant Diversity and Ecosystem Functioning: Observations Based on 5 Years' Manipulation of N Dose and Form in a Mediterranean Ecosystem

ABSTRACTFacilitation by legume nurse plants increase understorey diversity and support diverse ecological communities. In turn, biodiversity shapes ecological networks and supports ecosystem functioning. However, whether and how facilitation and increased biodiversity jointly influence community structure and ecosystem functioning remains unclear.We performed a field experiment disentangling the relative contribution of nurse plants and increasing understorey plant diversity in driving pollination interactions to quantify the direct and indirect contribution of facilitation and diversity to ecosystem functioning. This includes analysing pollinator communities in the following treatment combinations: (i) absence and presence of nurse plants, and (ii) understorey richness with none, one and three plant species.Facilitation by legume nurse plants and understorey diversity synergistically increase pollinator diversity. Our findings reflect diverse assemblages in which complementarity and cooperation among different plants result in no costs for individual species but benefits for the functioning of the community and the ecosystem. Drivers of network change are associated with increasing frequency of visits and non-additive changes in pollinator community composition and pollination niches.Synthesis Plant–plant facilitative systems, where a nurse shrub increases understorey plant diversity, positively influences mutualistic networks via both direct nurse effects and indirect plant diversity effects. Supporting such nurse systems is crucial not only for plant diversity but also for ecosystem functioning and services.

Download Full-text

Non-linear response of Mediterranean ecosystem to interaction of drought and plant invasion

10.5194/egusphere-egu21-1518 ◽

2021 ◽

Author(s):

Simon Haberstroh ◽

Maria C. Caldeira ◽

Raquel Lobo-do-Vale ◽

Joana I. Martins ◽

Julia Moemken ◽

...

Keyword(s):

Global Change ◽

Ecosystem Functioning ◽

Linear Response ◽

Plant Invasion ◽

Terrestrial Ecosystems ◽

Cork Oak ◽

Mediterranean Ecosystem ◽

Tree Transpiration ◽

Non Linear ◽

The Impact

The impact of interacting global change stressors on terrestrial ecosystems is hard to predict due to non-linear, amplifying, neutral or even buffering interaction effects. We investigated the effects of drought and plant invasion on Mediterranean cork oak (Quercus suber L.) ecosystem functioning and recovery with a combined rain exclusion (30-45 % reduction) and shrub (Cistus ladanifer L.) invasion experiment. As key parameter, we determined tree, shrub and ecosystem transpiration in four treatments: 1) cork oak control stands, 2) cork oaks with rain exclusion, 3) cork oaks invaded by shrubs and 4) cork oaks with rain exclusion and shrub invasion. Rain exclusion and plant invasion led to moderate, but neutral reductions of tree transpiration of 18 % (compared to control) during the mild summer drought in 2018. In 2019, the rain exclusion simulated the second driest year since 1950 for Southwestern (SW) Iberia. The interaction effect of drought and plant invasion was strongly amplifying, reducing tree transpiration by 47 %. Legacy effects on shrubs under the rain exclusion treatment led to a non-linear response during recovery from the severe drought in 2019. Invaded trees showed a delayed transpiration recovery (-51 % vs. control) due to strong competition with shrubs, while invaded trees with rain exclusion recovered to 75 % of the control. This buffering interaction response was caused by a weaker competition from drought-stressed shrubs. Given the projected increase in the frequency, intensity and duration of drought, an increasing non-linear impact on Mediterranean cork oak ecosystems is expected. Our results demonstrate that abiotic stressors modulate biotic interactions thereby impacting ecosystem functioning in a highly dynamic manner. Further efforts are thus needed to model and manage the impact of interacting global change stressors on terrestrial ecosystems.

Download Full-text

Understanding the value of plant diversity for ecosystem functioning through niche theory

Proceedings of The Royal Society B Biological Sciences ◽

10.1098/rspb.2016.0536 ◽

2016 ◽

Vol 283 (1844) ◽

pp. 20160536 ◽

Cited By ~ 45

Author(s):

Lindsay A. Turnbull ◽

Forest Isbell ◽

Drew W. Purves ◽

Michel Loreau ◽

Andy Hector

Keyword(s):

Plant Diversity ◽

Real World ◽

Ecosystem Functioning ◽

Species Coexistence ◽

Future Research ◽

Biological Processes ◽

Niche Theory ◽

Natural Ecosystems ◽

Empirical Results ◽

Simple Mapping

Biodiversity experiments have generated robust empirical results supporting the hypothesis that ecosystems function better when they contain more species. Given that ecosystems provide services that are valued by humans, this inevitably suggests that the loss of species from natural ecosystems could diminish their value. This raises two important questions. First, will experimental results translate into the real world, where species are being lost at an alarming rate? And second, what are the benefits and pitfalls of such valuation exercises? We argue that the empirical results obtained in experiments are entirely consistent with well-established theories of species coexistence. We then examine the current body of work through the lens of niche theory and highlight where closer links with theory could open up opportunities for future research. We argue that niche theory predicts that diversity–functioning relationships are likely to be stronger (and require more species) in the field than in simplified experimental settings. However, we caution that while many of the biological processes that promote coexistence can also generate diversity–function relationships, there is no simple mapping between the two. This implies that valuation exercises need to proceed with care.

Download Full-text

Positive Plant Diversity-Soil Stability Relationships are Mediated through Roots in the Songnen Grassland: Chronosequence Evidence

Notulae Botanicae Horti Agrobotanici Cluj-Napoca ◽

10.15835/nbha4129306 ◽

2013 ◽

Vol 41 (2) ◽

pp. 626 ◽

Cited By ~ 3

Author(s):

Liang-Jun HU ◽

Ping LI ◽

Qinfeng GUO

Keyword(s):

Plant Diversity ◽

Ecosystem Functioning ◽

Plant Root ◽

Eastern China ◽

Sample Survey ◽

Soil Stability ◽

Successional Stage ◽

Living Plant ◽

Time Substitution

Living plant diversity (excluding the litter issue) may affect below-ground properties and processes, which is critical to obtaining an integrated biodiversity-ecosystem functioning theory. However, related patterns and underlying mechanisms have rarely been examined, especially lacking long-term evidence. We conducted a factorial crossed sample survey to examine the effects of plant diversity on soil stability over succession based on space-for-time substitution in the Songnen Steppes, North-Eastern China. The results indicate that, under natural colonizing conditions, species-poor systems achieved lower soil stability than species-rich systems, regardless of successional stage. However, soil stability was significantly regulated by plant species richness (number), composition (identity), density (abundance), and functional roles. Our results confirm that a long-term positive plant diversity-soil stability relationship exists in steppe succession. In particular, this enhanced effect of biodiversity on soil stability may operate via diversifying plant root traits. Our results may underpin an integrated biodiversity-ecosystem functioning theory, and improve human use and conservation management of natural resources at an integrated ecosystem level.

Download Full-text

Decomposer diversity and identity influence plant diversity effects on ecosystem functioning

Ecology ◽

10.1890/11-2266.1 ◽

2012 ◽

Vol 93 (10) ◽

pp. 2227-2240 ◽

Cited By ~ 50

Author(s):

Nico Eisenhauer ◽

Peter B. Reich ◽

Forest Isbell

Keyword(s):

Plant Diversity ◽

Ecosystem Functioning ◽

Diversity Effects

Download Full-text

Utilizing principles of Biodiversity Science to Guide Soil Microbial Communities for Sustainable Agriculture

10.32942/osf.io/tm5eh ◽

2021 ◽

Author(s):

Seraina Lisa Cappelli ◽

Luiz Domeignoz Horta ◽

Viviana Loaiza ◽

Anna-Liisa Laine

Keyword(s):

Microbial Communities ◽

Plant Diversity ◽

Ecosystem Functioning ◽

Production Systems ◽

Soil Microbial Communities ◽

Empirical Support ◽

Soil Biodiversity ◽

Sustainable Food ◽

Soil Microbial ◽

Below Ground

While the positive relationship between plant biodiversity and ecosystem functioning (BEF) is relatively well-established, far less in known about the extent to which this relationship is mediated via below-ground microbial responses to plant diversity. Limited evidence suggests that the diversity of soil microbial communities is sensitive to plant community structure, and that diverse soil microbial communities promote functions desired of sustainable food production systems such as enhanced carbon sequestration and nutrient cycling. Here, we discuss available evidence on how plant diversity could be utilized to purposefully guide soil biodiversity in agricultural systems that are typically depleted of biodiversity, and are notoriously sensitive to both biotic and abiotic stressors. We outline the direct and soil microbe-mediated mechanisms expected to promote a positive BEF relationship both above- and below-ground. Finally, we identify management schemes based on ecological theory and vast empirical support that can be utilized to maximize ecosystem functioning in agroecosystems via biodiversity implementation schemes.

Download Full-text

Nitrogen and phosphorus resorption efficiencies change under drought and shrub encroachment in a Mediterranean ecosystem

10.5194/egusphere-egu2020-19834 ◽

2020 ◽

Author(s):

Raquel Lobo-do-Vale ◽

José Rodrigues ◽

Joana Martins ◽

Simon Haberstroh ◽

Ana Alves ◽

...

Keyword(s):

Ecosystem Functioning ◽

Mediterranean Ecosystems ◽

Shrub Encroachment ◽

Cork Oak ◽

Mediterranean Ecosystem ◽

Combined Effects ◽

Resorption Efficiency ◽

Nitrogen And Phosphorus ◽

Evergreen Species ◽

Effects Of Drought

Mediterranean ecosystems, such as the savannah-type cork oak (Quercus suber) woodlands, are hotspots for climate change, as the highest impacts are forecasted for the Mediterranean region, mainly by more frequent and intense severe droughts. These ecosystems are also threatened by shrub encroachment, which might further decrease tree water availability and affect ecosystem functioning and resilience. Nevertheless, the combined effects of drought and shrub encroachment on ecosystems have seldom been investigated. A precipitation manipulation and shrub removal experiment was established in a cork oak woodland located in SE Portugal and invaded by the native shrub gum rockrose (Cistus ladanifer). Here we present and discuss the combined effects of drought and shrub encroachment on litterfall production of cork oak trees, an evergreen species, over two contrasting years, a wet year (2018) and a dry year (2019) and assess the nitrogen and phosphorus resorption efficiencies from senescent to green leaves. A previous study reported significant increases in cork oak&#8217;s nitrogen resorption efficiency in response to drought. Our preliminary results also indicate changes in nitrogen and phosphorus resorption efficiencies. An increase in nutrient resorption efficiency is likely to mitigate the limitation in nutrient uptake by the roots during drought, improving tree fitness in the short-term. However, it will probably exert a negative feedback on the nitrogen and phosphorus cycles in the long-term which might affect the ecosystem functioning under the forecasted droughts.

Download Full-text

Diversity-dependent plant-soil feedbacks underlie long-term plant diversity effects on primary productivity

10.1101/376269 ◽

2018 ◽

Author(s):

Nathaly R. Guerrero-Ramírez ◽

Peter B. Reich ◽

Cameron Wagg ◽

Marcel Ciobanu ◽

Nico Eisenhauer

Keyword(s):

Plant Communities ◽

Plant Diversity ◽

Ecosystem Functioning ◽

Nitrogen Availability ◽

Soil Nitrogen Availability ◽

Plant Soil ◽

Soil Legacy ◽

Main Driver ◽

Underlying Mechanisms ◽

Diversity Effects

AbstractAlthough diversity-dependent plant-soil feedbacks (PSFs) may contribute significantly to plant diversity effects on ecosystem functioning, the influence of underlying abiotic and biotic mechanistic pathways have been little explored to date. Here, we assessed such pathways with a PSF experiment using soil conditioned for ≥12 years from two grassland biodiversity experiments. Model plant communities differing in diversity were grown in soils conditioned by plant communities with either low- or high-diversity (soil history). Our results reveal that plant diversity can modify plant productivity through both diversity-mediated plant-plant and plant-soil interactions, with the main driver (current plant diversity or soil history) differing with experimental context. The underlying mechanisms of PSFs were explained to a significant extent by both abiotic and biotic pathways (specifically, nematode richness and soil nitrogen availability). Thus, effects of plant diversity loss on ecosystem functioning may persist or even increase over time because of biotic and abiotic soil legacy effects.

Download Full-text