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

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

<p>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 (<em>Quercus suber</em> L.) ecosystem functioning and recovery with a combined rain exclusion (30-45 % reduction) and shrub (<em>Cistus ladanifer</em> 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.</p>

The European Ecotron of Montpellier: experimental platforms to study ecosystem response to climate change

2020 ◽  
Author(s):  
Joana Sauze ◽  
Jacques Roy ◽  
Clément Piel ◽  
Damien Landais ◽  
Emmanuel S Gritti ◽  
...  
Keyword(s):  
Climate Change ◽  
Ecosystem Functioning ◽  
Soil Depth ◽  
Land Use Changes ◽  
Terrestrial Ecosystems ◽  
Experimental Unit ◽  
Natural Ecosystems ◽  
Ecological Processes ◽  
Canopy Area ◽  
The Impact

<p>The sustainability of agricultural, forested and other managed or natural ecosystems is critical for the future of mankind. However, the services provided by these ecosystems are under threat due to climate change, loss of biodiversity, and land use changes. In order to face the challenges of preserving or improving ecosystems services and securing food supply we need to understand and forecast how ecosystems will respond to current and future changes. To help answer those questions Ecotrons facilities are born. Such infrastructures provide sets of confinement units for the manipulation of environmental conditions and real-time measurement of ecological processes under controlled and reproduceable conditions, bridging the gap between the complexity of in natura studies and the simplicity of laboratory experiments.</p><p>The European Ecotron of Montpellier (www.ecotron.cnrs.fr) is an experimental research infrastructure for the study of the impact of climate change on ecosystem functioning and biodiversity. This infrastructure offers, through calls open to the international community, three experimental platforms at different scales. The Macrocosms platform is composed of twelve 40 m<sup>3</sup> units, each able to host 2-12 t lysimeters, with a 2-5 m² canopy area and a soil depth of up to 2 m. The Mesocosms one has eighteen 2-4 m<sup>3</sup> units, each able to host lysimeters of 0.4-1 m depth and 0.4-1 m² area. The Microcosms platform consists of growth chambers (1 m height, 1 m² area) in which smaller units (with photosynthetic plants, soils, insects, etc.) can be installed. Each experimental unit of each platform allows to confine terrestrial ecosystems. This way, environmental parameters such as temperature (-10 to +50 °C), relative humidity (20-80 %), precipitation (sprinkler or drip) and atmospheric CO<sub>2</sub> concentration (200-1000 ppm) are strictly and continuously controlled and recorded. But the uniqueness of the European Ecotron of Montpellier lies on its ability to also continuously measure, in each unit, net gas exchange (evapotranspiration, CO<sub>2</sub> / CH<sub>4</sub> / N<sub>2</sub>O net fluxes) that occur in between the ecosystem studied and the atmosphere, as well as CO<sub>2</sub>, H<sub>2</sub>O, N<sub>2</sub>O and O<sub>2</sub> isotopologues. Those tools are powerful and remarkable to access additional information about processus involved in ecosystem functioning.</p><p>The aim of this presentation is to describe the Macrocosms and the Mesocosms platforms through examples of international projects recently run in these platforms.</p>

Biodiversity and ecosystem functioning in terrestrial habitats of Antarctica

2005 ◽  
Vol 17 (4) ◽  
pp. 523-531 ◽  
Author(s):  
DIANA H. WALL
Keyword(s):  
Global Change ◽  
Ecosystem Functioning ◽  
Ecosystem Processes ◽  
Global Changes ◽  
Biodiversity And Ecosystem Functioning ◽  
Soil Ecosystems ◽  
Terrestrial Habitats ◽  
Terrestrial Biodiversity ◽  
The Impact ◽  
Continental Interior

Are we failing to acknowledge the impact of global changes (e.g. UVB, invasive species, climate, land use, atmosphere) on the terrestrial biodiversity and ecosystem processes of Antarctica? Antarctica is considered a pristine environment and has low terrestrial species diversity and trophic complexity, and yet while scientifically possible, we still do not know the number of species, where they are, or how their influence on ecosystem processes (e.g. nutrient cycling, carbon flux, decomposition, feedbacks to climate, hydrology) will be affected by multiple global changes. Increased recognition of human dependence on services provided by biodiversity and ecosystem functioning combined with documented impacts of global change already occurring on Antarctic soil ecosystems, increases the urgency to expand investigations regionally in Antarctica. We cannot measure the effects of global change or sustainably manage Antarctica's future if we underestimate the contribution of soil communities. Evidence indicates habitats of rocky moraines, soils and cyroconite holes of glaciers in the continental interior may host not only microbes, but also a complexity of algae and invertebrates. Scientists of many disciplines, together, need to assess the benefits humans derive from Antarctic terrestrial biodiversity and ecosystem processes, how these will be affected by global change, and link their findings to the rest of the world.

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

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

<p>Mediterranean ecosystems, such as the savannah-type cork oak (<em>Quercus suber</em>) 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 (<em>Cistus ladanifer</em>). 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.</p> <p>A previous study reported significant increases in cork oak’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.</p>

scholarly journals Non-linear responses of net ecosystem productivity to gradient warming in a paddy field in Northeast China

PeerJ ◽  
2020 ◽  
Vol 8 ◽  
pp. e9327
Author(s):  
Yulu Sun ◽  
Fuyao Qu ◽  
Xianjin Zhu ◽  
Bei Sun ◽  
Guojiao Wang ◽  
...  
Keyword(s):  
Global Warming ◽  
Paddy Field ◽  
Linear Response ◽  
Northeast China ◽  
Ecosystem Respiration ◽  
Far Infrared ◽  
Net Ecosystem Productivity ◽  
Ecosystem Productivity ◽  
Non Linear ◽  
The Impact

Global warming has a known impact on ecosystems but there is a lack of understanding about its impact on ecosystem processes. Net ecosystem productivity (NEP) and its components play a key part in the global carbon cycle. Analysing the impact of global warming on NEP will improve our understanding of how warming affects ecosystems. In our study, conducted in 2018, five warming treatments were manipulated (0 W, 500 W, 1000 W, 1500 W, and 3000 W) using three repetitions of far infrared open warming over a paddy field in Northeast China. NEP and its two related components, gross primary productivity (GPP) and ecosystem respiration (ER), were measured using the static chamber-infrared gas analyser method to explore the effects of different warming magnitudes on NEP. Results showed that measurement dates, warming treatments, and their interactions significantly affected NEP, ER, and GPP. Warming significantly increased NEP and its components but they showed a non-linear response to different warming magnitudes. The maximum increases in NEP and its components occurred at 1500 W warming. NEP is closely related to its components and the non-linear response of NEP may have primarily resulted from that of GPP. Gradient warming non-linearly increased GPP in the paddy field studied in Northeast China, resulting in the non-linear response of NEP. This study provides a basis for predicting the responses of carbon cycles in future climate events.

Flow velocity and light level drive non-linear response of seagrass Zostera noltei to ammonium enrichment

2016 ◽  
Vol 545 ◽  
pp. 109-121 ◽  
Author(s):  
B Villazán ◽  
FG Brun ◽  
V González‑Ortiz ◽  
F Moreno‑Marín ◽  
TJ Bouma ◽  
...  
Keyword(s):  
Flow Velocity ◽  
Linear Response ◽  
Light Level ◽  
Zostera Noltei ◽  
Non Linear

Climate-forced changes of bio-productivity of Belorussian terrestrial ecosystems

2019 ◽  
pp. 77-88
Author(s):  
S. A. Lysenko
Keyword(s):  
Climate Change ◽  
Carbon Dioxide ◽  
Vegetation Index ◽  
Precipitation Amount ◽  
Terrestrial Ecosystems ◽  
Vegetation Period ◽  
Climatic Trend ◽  
Vegetation Growth ◽  
Current Century ◽  
The Impact

The spatial and temporal particularities of Normalized Differential Vegetation Index (NDVI) changes over territory of Belarus in the current century and their relationship with climate change were investigated. The rise of NDVI is observed at approximately 84% of the Belarus area. The statistically significant growth of NDVI has exhibited at nearly 35% of the studied area (t-test at 95% confidence interval), which are mainly forests and undeveloped areas. Croplands vegetation index is largely descending. The main factor of croplands bio-productivity interannual variability is precipitation amount in vegetation period. This factor determines more than 60% of the croplands NDVI dispersion. The long-term changes of NDVI could be explained by combination of two factors: photosynthesis intensifying action of carbon dioxide and vegetation growth suppressing action of air warming with almost unchanged precipitation amount. If the observed climatic trend continues the croplands bio-productivity in many Belarus regions could be decreased at more than 20% in comparison with 2000 year. The impact of climate change on the bio-productivity of undeveloped lands is only slightly noticed on the background of its growth in conditions of rising level of carbon dioxide in the atmosphere.

Non-linear response of stomata in Pinus koraiensis to tree age and elevation

Trees ◽  
2012 ◽  
Vol 26 (4) ◽  
pp. 1389-1396 ◽  
Author(s):  
Yumei Zhou ◽  
Marcus Schaub ◽  
Lianxuan Shi ◽  
Zhongling Guo ◽  
Anan Fan ◽  
...  
Keyword(s):  
Linear Response ◽  
Tree Age ◽  
Pinus Koraiensis ◽  
Non Linear
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