Joint Action of the EFIATLANTIC / IEFC "Soils and Water Group

Transcription

1 Joint Action of the EFIATLANTIC / IEFC "Soils and Water Group Ander Arias-González Nahia Gartzia-Bengoetxea Lur Moragues-Saitua Bilbao- 2014/04/29 th

2 Carbon equilibrium in Earth Reservoir Carbon (Pg) Land-System Biomass 550 Soils 1500 Atmosphere 750 Oceans Geologic (fossil 4000 fuel) Total 44800

3 Carbon equilibrium in Earth Temperate forests: net carbon sink 0.7±0.2 Pg C/yr CO 2 production: Respiration from roots and microbial decmposition of SOM. Both processes depend on temperature (also on availability of water). Rate of decomposition depends on specific factors: soil texture, ph, nutrient availability etc. influencing the quality of the organic matter and the microbial community that performs decomposition.

4 Temperature sensitivity of the mineralization of organic matter in soils Represented by the Q 10 parameter The increase in the rate of reaction for every 10º C increase in temperature

5 Hypothesis We hypothesized that the decomposition of SOM is adapted to the SOM quality and the climatic conditions under which decomposition takes place. As a result: different temperature vs. decomposition curves for northern and southern soils

6 Reasons (1) Northern soils have accumulated incompletely decomposed SOM (2) Plant cover and therefore the quality of organic C input to the soil varies according to prevailing climatic conditions (3) Soil microbial community structure and its ability to utilize specific carbon substrates are adapted to prevailing conditions. However, microbial communities have the ability to adapt to new conditions, and different microbial communities may function in different ways under different conditions

7 What are we seeking? We want to homogenize the different factors that affect SOM decomposition to study the effect of climate on it. We shall select a network of stands under the same species, with soils of similar textural classes and homogeneous phs in a latitudinal gradient from South to North. This gradient may be used as a surrogate of climate change assuming that nowadays climate in some concrete places of this gradient may be similar to the climate some other part of it will have in the future.

8 Objective Soils formed in different geographical locations and conditions respond to temperature changes to evaluate its implications in the Climate Change feedback Determine temperature sensitivity of SOM decomposition covering a latitudinal gradient from South to North. Characterization of SOM in a latitudinal gradient from South to North. Characterization of soil microbial communities in a latitudinal gradient from South to North.

9 Partners Elena Vanguelova Peter Crow

10 Partners Mark Bakker Laurent Augusto Anne Budynek

11 Partners Nahia Gartzia-Bengoetxea Lur Moragues-Saitua Ander Arias-González

12 Partners Nieves Barros

13 Partners Margarita Alonso Santos María José Rozados Lorenzo

14 Partners Afonso Martins

15 Partners Manuel Madeira

16 Partners

17 Methods: Site selection Quercus robur stands On Acidic soils With sandy texture 3 sites per Region (replicates of Climate).

18 Methods: Site selection Quercus robur stands On Acidic soils With sandy texture 3 sites per Region (replicates of Climate).

19 Methods: Site selection

20 Methods: Sampling 4 different mixed samples and soil cores in each stand: (i) One L+F organic layers sample (ii) One H organic layer sample (iii) One mineral soil sample (5cm) (iv)five different mineral soil cores for Bulk density determination

21 Methods: Sampling In each stand 5 Q. robur trees will be randomly selected DBH Total height Height where the crown begins Crown cover Maximum and minimum crown radius

22 Methods: Sampling At half of the maximum crown: sampling site will be selected. Samples of 2000 cm 2 Organic Horizons: All the organic material present in the sampling site gathered. L+F together. The depth will be recorded H until mineral soil. Recording also the depth The L+F samples from each horizon and from the 5 trees mixed together. Mineral soil: same pointd: A cylinder of known volume will be taken for Bulk density determination (5 cm deep; 5 cm diameter). Another 3 similar cylinders (for analytical purposes) will also be collected (collection depth: 5 cm). These samples mixed together.

23 Methods: Analysis Physical fractionation of SOM Chemical fractionation of SOM

24 Methods: Analysis Forest floor chemical analysis Forest floor polyphenols Soil Texture

25 Methods: Analysis Thermal analysis and calorimetric measurements of soils

26 Methods: Analysis Microbial CNP measurements and associated enzymatic tests

27 Methods: Analysis Soil chemical analysis

28 Methods: Analysis Fibers in forest floor Soil respirations at 5, 15, 25ºC Substrate induced respirations DGGE analysis Ergosterol content

29 Methods: Analysis

30 Previous Results

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