SOM through the soil profile in a climate-stressed environment

Associate Professor Brian Wilson1

1University of New England, Australia

Biography:

Associate Professor Brian Wilson completed his PhD in Soil Science at the University of Reading in the UK. He held positions as an academic in the UK and, following a move to Australia in 1999, has worked as a Research Scientist with New South Wales (NSW) State Government and more recently as an academic at University of New England (UNE). His research has focused principally on soil organic matter quantity, distribution and dynamics across a range of land-uses, especially native vegetation systems, in Europe, Australia and the sub-Antarctic, utilising a variety of elemental, stable- and radio-isotope techniques. He leads the Terrestrial Carbon Research Group at UNE which has examined a range of processes and mechanisms of soil organic matter storage and movement in the soil profile in response to land use and management pressures in the climate-stressed, NSW environment. Current work within the group focuses on the addition and stabilisation of carbon through the whole soil profile from plant/root contributions and dissolved organic carbon combined with soil organic matter cycling and change in Australian alpine and island environments. A/Prof Wilson continues a close research collaboration with the NSW State Government focusing on key Statewide research and policy needs relating to soils and the development of strategic research initiatives.

Effect of drought stress on soil organic matter dynamics in salt-affected soils

Dr Muhammad Sanaullah1, Mr. Abdul Qadeer1, Dr Abdul Wakeel1

1Institute of Soil & Environmental Sciences, University Of Agriculture, Faisalabad, Pakistan

Due to anthropogenic activities, greenhouse gases (GHGs) emissions, especially CO2 emissions have increased alarmingly, leading to climate change. These climatic changes result in uncertain rainfall causing drought stress and elevated global temperature which can have direct impacts on soil health and its functioning. Soil salinity is also increasing because of climate change. The aims of this research were to elucidate the effects of drought stress on soil organic matter (SOM) dynamics and health of normal and saline soils. An incubation experiment was carried out in controlled conditions where 50 g soil was used. Three different moisture levels optimum conditions, moderate drought and severe drought stress were maintained in normal and saline soils. Microbial biomass C as well as cumulative C-CO2 emissions were significantly higher in saline soils at optimum conditions compared with normal soil. While under drought stress, it was reverse than optimum conditions. Enzymatic analysis revealed that soil extracellular enzymes activities i.e. glucosidase, phosphatase, Leucine amino peptidase activity was significantly high at optimum conditions in normal soil while chitinase activity was also increased in saline soil but at moderate drought stress. It was concluded that the impact of climate change on SOM dynamics is different in normal and saline soils and GHGs emissions contribution from salt-affected soils must be considered separately.


Biography:

Bio to Come

 

Temperature sensitivity of soil organic carbon decomposition and priming across a productivity gradient in Australian eucalypt forests

Dr.  Namjin Noh1, Dr Elise Pendall1, Mr Jinquan Li1,2, Dr.  Georgia Koerber3, Dr Wayne Meyer3, Dr Will Woodgate4, Dr Stefan Arndt5, Dr Eric Davidson6

1Western Sydney University, Penrith, Australia, 2Fudan University, Shanghai, China, 3University of Adelaide, Adelaide, Australia, 4CSIRO, Canberra, Australia, 5University of Melbourne, Melbourne, Australia, 6University of Maryland, Frostburg, USA

Understanding temperature sensitivity of soil organic carbon (SOC) decomposition in relationship to substrate availability and priming effects is critical for predicting climate-carbon feedbacks. Here, thermal response of SOC decomposition and substrate-induced priming were investigated using 13C-labeled Eucalyptus leaf litter for surface soils sampled in six eucalypt forests and woodlands across the Southeast Australian Temperate Transect (SATT). The selected sites belong to the Australian Terrestrial Ecology Research Network and form a gradient of increasing productivity with mean annual precipitation increasing from 300 to >1000 mm. The priming effect was computed from respired CO2 flux and associated δ13C, which were measured for 3 weeks in laboratory microcosms at incubation temperatures of 5, 15, and 25°C. Litter addition resulted in stimulation of total soil CO2 flux as substrate-induced respiration (SIR) for all forest soils, but the magnitude of the SIR was dependent on substrate availability across the sites, indicating SIR was higher at the sites with lower productivity. Addition of fresh litter significantly decreased temperature sensitivity (Q10) of SOC decomposition due to the negative correlation between Q10 and carbon quality. The Q10 of litter C was lower than that of SOC suggesting that soil C is relatively more vulnerable to climate warming, potentially due to its greater complexity. On the other hand, the priming effect of litter substrate on SOC decomposition was negative and more pronounced at higher temperature, indicating reduced SOC loss with warming in the presence of fresh litter. Our results demonstrate that temperature sensitivity of SOC decomposition was lower and (negative) priming was greater at the sites with more SOC across the SATT productivity gradient. These results suggest potential substrate-dependent mechanisms that may enhance SOC stabilization in future climates.


Biography:

Elise Pendall is Professor of Soil Science at Western Sydney University and serves as Theme Leader for the Soil Biology and Genomics research group at Hawkesbury Institute for the Environment. She studies responses of biogeochemical cycling to climate change, ecological disturbances and land management. She uses field and lab experiments and modelling to evaluate linkages between aboveground and belowground ecosystem components and how they regulate carbon, water and nutrient cycling in forests, grasslands, and crops.

 

SOM dynamics in fire prone landscapes

Dr Jennifer Soong1

1Lawrence Berkeley National Laboratory

Abstract:

The occurrence of wildfires is increasing globally, yet their impact on SOM dynamics is not very well understood. The impact of fires on SOM can vary greatly with ecosystem type, fuel load condition and fire severity. Although fires combust and remove biomass from ecosystems, they also transform the litter layer, top soil and plant material leaving behind pyrogenic organic matter residues. Pyrogenic organic matter has chemical and structural properties that impedes decomposition by biota but also retains nutrients and impacts hydrology in the soil. Surface litter and pyrogenic organic matter also have very different decomposition pathways to SOM formation, which can help to explain the impact of frequent burning on soil carbon and nitrogen dynamics. I will present an overview of how the study of SOM characteristics and dynamics in fire-prone landscapes has evolved rapidly in recent years and discuss the upcoming needs and opportunities for SOM researchers to inform better management and planning for the future in fire-prone landscapes.

Biography:

Jennifer Soong is a postdoctoral fellow at Lawrence Berkeley National Laboratory. She earned her PhD in Ecology from Colorado State University and her B.A. from Oberlin College. Dr. Soong’s research focuses on biogeochemistry and ecosystem ecology with an emphasis on how terrestrial ecosystems function under natural and human-influenced environmental conditions. She conducts observational and experimental studies in field and laboratory across a broad range of ecosystem types, using techniques such as stable isotope probing, molecular techniques and modeling to quantify how organic and inorganic materials are transported and transformed as they move through plant-soil-microbial-atmospheric interfaces. Dr. Soong works closely with modelers to scale new mechanistic insights to ecosystem and global scales and help improve predictions of future ecosystem functioning.

A generalized framework for the detection of range shifts from “resurvey” studies

Morgan W. Tingley 1
1 Department of Ecology and Evolutionary Biology, University of Connecticut, 75 N. Eagleville Rd Unit 3043, Storrs CT 06103 USA,

morgan.tingley@uconn.edu, @mwtingley

Long-­‐term, large-­‐scale environmental change necessitates empirical studies that span time frames from decades to centuries. As this length of time often precludes planned experiments, an increasingly popular option in ecology is the “resurvey” study, or the revisitation of past research sites. An important emerging issue is how researchers can use past survey data to make analytically robust comparisons. Previous work has largely acknowledged this problem while employing a diverse set of strategies, statistical or otherwise, to account for bias. While no single analytical framework will satisfy the needs of all researchers, the increasing popularity of resurvey studies demands a generalized accounting of inferential problems as well as common strategies for overcoming them. This presentation outlines how statistical methods can be used to account for bias derived from issues such as imperfect detection, shifting taxonomies, unknown or changing spatial sampling, differing survey methodologies, and varying levels of survey effort. Among various methodological options, emphasis will be placed on the flexible nature of state-­‐space models to allow the inclusion, characterization, and estimation of multiple sources of uncertainty deriving from both state and observation processes. While such analytical tools show great potential in resurvey studies, their prospective success relies on the standards by which both past data and new data are collected. Thus, whether we are resurveying the past or setting baselines for the future, changing how we survey – in addition to changing how we analyze data – will play a key role in the future measurement and documentation of species on the move.

Twitter: @mwtingley

The responsiveness and adaptability of Commonwealth fisheries management to climate change

Danait Ghebrezgabhier(1) and Giulia Porro (2)
(1)Australian Fisheries Management Authority (AFMA), PO Box 7051, ACT 2610, Danait.Ghebrezgabhier@afma.gov.au, @azmarinae
(2) Australian Fisheries Management Authority (AFMA), PO Box 7051, ACT 2610, Giulia.Porro@afma.gov.au, @loveateverybite

This presentation explores whether tools utilised to manage Commonwealth fisheries allow for adaptive management and sustainable exploitation of fisheries resources in response to climate change.The various management tools used by AFMA have the potential to take into account environmentalfactors that may influence the size and/or distribution of commercial fish stocks. These include management via output controls, temporal and spatial management measures and data collection and monitoring programs.

Whilst the current management system works well, AFMA acknowledges that it has limits and is participating in research to:

  • increase its awareness of the true impact of fisheries on the environment relative to other industries and externalities,
  • identify the environmental variables that drive the distribution of commercial fish stocks and the potential to use predictive tools to monitor their impact over time.

Our presentation will also provide an overview of how:

  • The quota system and the setting of total allowable catches allow for adaptive management and encourage sustainable fishing.
  • The relatively large geographical boundaries of the fisheries that AFMA manages provide industry with the flexibility and space to follow key commercial species.
  • AFMA has data collection programs that could be used or adapted to explore changes in the pattern of fish stock composition and distribution over time.
  • Current and future research investments will allow for the development of predictive tools that will anticipate significant environmental changes and help AFMA develop adaptive fisheries
    management options for a range of environmental scenarios.
  • To determine the weight of evidence/test required to implement adaptive management.

Australian National Adaptation Research Plan for Terrestrial Biodiversity feedback session

Prof Stephen Williams

The primary aim of the National Adaptation Research Plan for Terrestrial Biodiversity (NARP-TB) is to identify the research required to assist managers and policy makers of Australia’s terrestrial biodiversity systems to prepare for, and adapt to, climate change. The plan identifies knowledge gaps with respect to helping terrestrial systems adapt to climate change, and develops priority research questions (PRQ’s) to enable researchers to focus their efforts on filling these gaps. These priority research questions are aimed at providing the knowledge to inform decisions on climate change adaptation management in terrestrial systems. This short discussion session will focus on the presentation of the PRQ’s and invite comment and feedback on the draft priority research questions.

Bioclimatic scaling: a middle-ground approach to assessing and addressing potential impacts of climate change on the distribution of biodiversity

Simon Ferrier (1), Thomas D Harwood (1), Kristen J Williams (1), Andrew Hoskins (1), Karel Mokany (1), Alex Bush (1), Chris Ware (1), Glenn Manion (2)

1   CSIRO Land and Water, PO Box 1600, ACT 2601, Australia

2   NSW Office of Environment and Heritage, University of New England 2351, Australia

Two broad analytical approaches have dominated efforts to assess potential impacts of climate change on the spatial distribution of biodiversity, and to thereby inform policy formulation, planning and management aimed at addressing these impacts. The first, and most widely applied, approach focuses on modelling shifts in the distribution of particular biological entities – mostly individual species, but also higher-level aggregations such as species assemblages or functional groups. The second approach focuses instead on analysing spatiotemporal patterns in climate alone – e.g. projections of climatic stability, velocity of climate change, and novel and disappearing climates, along with consideration of such patterns in adaptation strategies aimed at “conserving nature’s stage”. An arguable strength of this approach is its utility for addressing regions and/or components of biodiversity where the data and understanding required to explicitly model biological responses are lacking. However, analyses of climate alone do not recognise that the level of biological change expected to be associated with a given amount of change in a climatic attribute can vary markedly between biological groups, environments, and biogeographic regions. We here describe how these sources of variation can be accommodated by combining best-available location records for large numbers of species, with statistical modelling of spatial turnover in species composition, to scale (transform) multidimensional climate space, such that distances within this transformed space correlate as closely as possible with observed levels of biological turnover. We then use recent analyses underpinned by this approach to demonstrate how it can serve as a third major option for assessing and addressing climate-change impacts on biodiversity, effectively occupying the middle ground between explicit modelling of shifts in biological distributions, and analyses based on spatiotemporal patterns in climate alone.

Alaska’s coastline and resources: tracking and response through networks, pilots and satellites

Torie Baker 1, Paula Cullenberg 2

1 Alaska Sea Grant Marine Advisory Program University of Alaska Fairbanks, Box 814, Cordova, Alaska, 99574, torie.baker@alaska.edu, @toriealaska1

2 Alaska Sea Grant University of Alaska Fairbanks, 1007 West Third, Suite 100, Anchorage, Alaska 99501, paula.cullenberg@alaska.edu , @pcullenberg

With over 40,000 miles of coastline, three out of four Alaskans, in nearly 260 communities, live either along the state’s coastline or along the rivers that bridge freshwater and marine coastal environments. This presentation highlights three representative remote, human-based observation and response programs active in coastal Alaska: NOAA’s Alaska Marine Mammal Stranding Network, invasive species monitoring arrangements, and the LEO Network for Native and rural Alaskans tracking climate and species anomalies. Alaska Sea Grant recently published a state-wide manual outlining successful strategies for community based monitoring in Alaska .As a leading international seafood producing region with over 8,000 registered commercial fishing vessels, plans for utilizing Alaska’s fishing fleets in monitoring and reporting fish species distribution, harmful alga blooms and climatic anomalies is being explored. The University of Alaska Fairbanks Alaska Sea Grant Program personnel actively contribute to network data collection across several topics, and is a leading partner in sharing of best practices for establishing successful monitoring programs throughout Alaska.

Climatic variability promotes asymmetric competition and exclusion in ectotherms

Shih-fan Chan

Climate change is known to modify both climatic mean and variability. Environmental
variability  has  long  been  considered  an  important  regulator  of  species  interactions,
particularly  interspecific  competition.  However,  although  increasing  studies  have
focused  on  the  biological  impacts  of  changing  climatic  mean  and  variability,  their
interacting  effects  on  species  interaction,  and  hence  species’  distribution,  were  less
explored.  Here,  we  investigate  how  changing  thermal  variation  and  mean  influence
the  competition  and  coexistence  between  burying  beetles,  Nicrophorus  nepalensis,
and  blowflies  along  a  large  elevational  gradient  in  central  Tai wan.   Our  field  study
shows that  habitat alteration increased daily temperature range (DTR)—a short‐term
thermal  variation—and  the  effect  was  more  pronounced  in  higher  elevation.  This
higher  DTR  negatively  impacted  the  breeding  success  of  N.  nepalensis  through
altering  the  competitive  interaction  between  N.  nepalensis  and  blowflies,  which,  in
turn, promoted the competitive exclusion of N. nepalensis. We further integrated the
thermal  performance  curve  and  Lotka‐Volterra  model  to  explore  the  general
relationship  between  climatic  mean  and  variability  on  the  competitive  relationship
between  species.  Results  from  the  model  showed  that  temperature  variability  can
cause both  coexistence and competitive exclusion depending on its interacting effect
with mean temperature. Our lab experiment on the competitive interaction between
N. nepalensis and blowflies further supported these model predictions. Together, our
study  provides  a  general  theoretical  framework  predicting  how  competitive
interaction  changes  with  temperature  mean  and  variability,  which  could  be
particularly  useful  for  predicting  the  changes  of  biotic  interactions  under  climate
change.

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SOIL ORGANIC MATTER

7th International Symposium
Soil Organic Matter

6 – 11 October 2019

Hilton Adelaide

Adelaide, South Australia

Australia

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