Reply on RC3 DOI Creative Commons
Chad Burton

Published: May 17, 2024

Abstract. Long-term, reliable datasets of satellite-based vegetation condition are essential for understanding terrestrial ecosystem responses to global environmental change, particularly in Australia which is characterised by diverse ecosystems and strong interannual climate variability. We comprehensively evaluate several existing AVHRR NDVI products their suitability long-term monitoring Australia. Comparisons with MODIS highlight significant deficiencies, over densely vegetated regions. Moreover, all the assessed failed adequately reproduce inter-annual variability pre-MODIS era as indicated Landsat anomalies. To address these limitations, we propose a new approach calibrating harmonising NOAA’s Climate Data Record MCD43A4 using gradient-boosting decision tree ensemble method. Two versions developed, one incorporating data predictors (‘AusENDVI-clim’: Australian Empirical NDVI-climate) another independent (‘AusENDVI-noclim’). These datasets, spanning 1982–2013 at spatial resolution 0.05°, exhibit correlation low relative errors compared NDVI, accurately reproducing seasonal cycles Furthermore, they closely replicate era. A method gap-filling AusENDVI record also developed that leverages climate, atmospheric CO2 concentration, woody cover fraction predictors. The resulting synthetic dataset shows excellent agreement observations. Finally, provide complete 41-year where gap filled from January 1982 February 2000 seamlessly joined March December 2022. Analysing 40-year per-pixel trends Australia’s annual maximum revealed increasing values across most continent. shifts timing peak identified, underscoring dataset's potential crucial questions regarding changing phenology its drivers. can be used studying Australia's dynamics downstream impacts on carbon water cycles, provides foundation further research into drivers change. open access available https://doi.org/10.5281/zenodo.10802704 (Burton, 2024).

Language: Английский

Bridge to the future: Important lessons from 20 years of ecosystem observations made by the OzFlux network DOI Creative Commons
Jason Beringer, Caitlin E. Moore, James Cleverly

et al.

Global Change Biology, Journal Year: 2022, Volume and Issue: 28(11), P. 3489 - 3514

Published: March 22, 2022

Abstract In 2020, the Australian and New Zealand flux research monitoring network, OzFlux, celebrated its 20 th anniversary by reflecting on lessons learned through two decades of ecosystem studies global change biology. OzFlux is a network not only for researchers, but also those ‘next users’ knowledge, information data that such networks provide. Here, we focus eight across topics climate variability, disturbance resilience, drought heat stress synergies with remote sensing modelling. distilling key learned, identify where further needed to fill knowledge gaps improve utility relevance outputs from OzFlux. Extreme variability Australia (droughts flooding rains) provides natural laboratory understanding ecosystems in this time accelerating change. As evidence worsening fire risk emerges, ability these recover disturbances, as cyclones, adaptation resilience disturbance. Drought heatwaves are common occurrences large parts region can tip an ecosystem's carbon budget net CO 2 sink source. Despite responses stress, at sites show their rapidly pivoting back strong upon return favourable conditions. Located under‐represented areas, have potential reducing uncertainties products, provide several opportunities develop new theories our models. The accumulated impacts over last years highlights value long‐term observations managed systems. A future vision includes ongoing newly developed ecophysiologists, ecologists, geologists, sensors modellers.

Language: Английский

Citations

43
Adaptive Capacity to Climate Change in Pastoral Areas DOI Open Access
Ziwei Wang, Zhichao Xue, Xuexia Zhang

et al.

Sustainability, Journal Year: 2025, Volume and Issue: 17(3), P. 1337 - 1337

Published: Feb. 6, 2025

The warming climate and increasing extreme weather events are transforming ecological backgrounds, which is bringing new challenges to herders’ livelihood in grassland areas. To understand the practical risks current resilience situations of behaviors government correspondence measures, we built a conceptual framework community pastoral areas, selected different kinds steppes along gradient (desert steppe, typical steppe meadow steppe) took household surveys recognize difference enhancing strategies types. results show that: (1) Herders desert with lowest precipitation worst condition, turn out have more experience perceiving droughts mitigating loss from disaster, but received most attention assistance (28.0%) getting through drought; (2) Typical traditionally better pastural husbandry environment, suffered broadly (85.7%) livestock (26.7%) snow storms; (3) Meadow has highest catastrophic storm ratio (65.0%) affected (95.0%), least (22.22%). revealed that originally high vulnerability gradually encouraged herder’s adaptive capability. However, inclined local original vulnerability. In addition, knowledge systems indigenous herders under good condition. There clear need combine efforts pastoralists, policymakers scientific together construct resilient socio-ecological global change. This research provides an in-depth understanding areas while facing slow-onset change impacts. Practical recommendations on risk management adaptation discussed.

Language: Английский

Citations

1
Land surface phenology indicators retrieved across diverse ecosystems using a modified threshold algorithm DOI Creative Commons
Qiaoyun Xie, Caitlin E. Moore, James Cleverly

et al.

Ecological Indicators, Journal Year: 2023, Volume and Issue: 147, P. 110000 - 110000

Published: Feb. 13, 2023

Land surface phenology (LSP), the study of seasonal vegetation dynamics from remote sensing imagery, provides crucial information for plant monitoring and reflects responses ecosystems to climate change. The Moderate Resolution Imaging Spectroradiometer (MODIS) product (MCD12Q2) global LSP information, but it has large spatial gaps in many regions, especially where rainfall influences more than temperature. This aimed improve coverage retrieval these ecosystems. To do so, we used a regionally modified threshold algorithm retrievals, which were tested over continental Australia as includes diverse landscapes arid, mesic, forest environments. We generated metrics annually 2003 2018 using satellite Enhanced Vegetation Index (EVI) time series at 500 m resolution, including start, peak, end, length growing seasons, minimum EVI value prior after peak date, maximum value, integral during season (an approximation productivity), amplitude (maximum minus EVI). Our optimised improved only 26 % continent 70 averaged across 16 years. results showed that was low (EVI < 0.1) arid/semi-arid shrublands savannas, tropical subtropical temperate evergreen forests, whose captured by our regional not product. Some ecosystems, such irregular with dynamics, seasons could skip year or occur once depending on conditions. sensitive amplitudes. found detectability increases increases, regardless cover. Evaluation eddy covariance flux tower measurements gross primary productivity (GPP) demonstrated reliability accuracy algorithm. These retrievals provide greater understanding savanna, shrubland, cover 30 land globally. essential ecological agricultural studies quantifying bushfire fuel accumulation carbon cycling, whilst enhancing capacity

Language: Английский

Citations

20
Estimation of global transpiration from remotely sensed solar-induced chlorophyll fluorescence DOI
Jingjing Yang, Zhunqiao Liu, Qiang Yu

et al.

Remote Sensing of Environment, Journal Year: 2024, Volume and Issue: 303, P. 113998 - 113998

Published: Jan. 18, 2024

Language: Английский

Citations

8
Nonstationary recharge responses to a drying climate in the Gnangara Groundwater System, Western Australia DOI Creative Commons
Simone Gelsinari, Sarah A. Bourke, James L. McCallum

et al.

Journal of Hydrology, Journal Year: 2024, Volume and Issue: 633, P. 131007 - 131007

Published: March 4, 2024

The response of groundwater recharge to climate change needs be understood enable sustainable management systems today and in the future, yet observations over long-enough time periods reveal responses trends are scarce. Here we present a meta-analysis 60 years studies Gnangara Groundwater System South-West Western Australia, covering period sustained drying consistent with projections. process area is defined by wet winter during which rain saturates deep, highly permeable soil profile very low water storage capacity. Measurements since 1960s show near-linear reductions potential 50%, 20% reduction rainfall. For best-represented land cover dataset (Banksia woodland), was closer 70%. A simple analytical model suggests that duration winter, coupled decreased frequency storms, were most responsible for these declines, reveals nonlinear relationships between fraction (recharge/precipitation) climatic variables such as mean storm frequency, depth, length season. Overall, results suggest declines Mediterranean likely outstrip rainfall, leveraging existing observation networks worldwide characterise changing needed overcome interpretation challenges created inconsistent sites, methods durations estimation.

Language: Английский

Citations

7
Principles for satellite monitoring of vegetation carbon uptake DOI
I. Colin Prentice, Manuela Balzarolo, Keith J. Bloomfield

et al.

Nature Reviews Earth & Environment, Journal Year: 2024, Volume and Issue: 5(11), P. 818 - 832

Published: Oct. 29, 2024

Language: Английский

Citations

7
Drivers of Decadal Carbon Fluxes Across Temperate Ecosystems DOI Creative Commons
Ankur R. Desai, Bailey Murphy, Susanne Wiesner

et al.

Journal of Geophysical Research Biogeosciences, Journal Year: 2022, Volume and Issue: 127(12)

Published: Dec. 1, 2022

Long-running eddy covariance flux towers provide insights into how the terrestrial carbon cycle operates over multiple timescales. Here, we evaluated variation in net ecosystem exchange (NEE) of dioxide (CO

Language: Английский

Citations

25
Introducing Pour Points: Characteristics and Hydrological Significance of a Rainfall‐Concentrating Mechanism in a Water‐Limited Woodland Ecosystem DOI Creative Commons
Ashvath Singh Kunadi, Tim Lardner, Richard Silberstein

et al.

Water Resources Research, Journal Year: 2024, Volume and Issue: 60(3)

Published: Feb. 29, 2024

Abstract The interception of rainfall by plant canopies alters the depth and spatial distribution water arriving at soil surface, thus location, volume, infiltration. Mechanisms like stemflow are known to concentrate route it deep into soil, yet other mechanisms flow concentration poorly understood. This study characterizes pour points, formed detachment flowing under a branch, using combination field observations in Western Australian banksia woodlands simulation experiments on Banksia menziesii branches. We aim establish hydrological significance points water‐limited woodland ecosystem, along with features canopy structure that influence point formation fluxes. Pour were common could be identified visually inspecting trees. Throughfall depths up 15 times greater than generally comparable or stemflow. Soil content beneath was adjacent controls, 20%–30% seasonal volume infiltrated top 1 m compared 5% controls. Rainfall simulations showed amplified heterogeneity throughfall, violating assumptions used close balance. demonstrated fluxes depend interaction branch angle foliation for given architecture. can play significant part balance, depending their density ability.

Language: Английский

Citations

5
Increased Compound Droughts and Heatwaves in a Double Pack in Central Asia DOI Creative Commons
Chuan Wang, Zhi Li, Yaning Chen

et al.

Remote Sensing, Journal Year: 2022, Volume and Issue: 14(13), P. 2959 - 2959

Published: June 21, 2022

Compound droughts and heatwaves (CDHWs) are likely to cause more severe natural disasters than a single extreme event, they have been exacerbated by rapid global warming. Based on high-resolution grid data, this study combines the daily-scale ERA5-Land dataset monthly-scale SPEI with multiple indicators analyze CDHWs. We calculated analyzed temporal spatial modal distribution of CDHWs in Central Asia from 1981 2018, paper, we discuss sequence relationship between drought events, heatwave The results show that number region increased over time expanded terms area, especially eastern southwestern Asia. tsum (total frequency CDHWs) was 0.5 times higher total it at rate 0.17/yr. maximum duration tmax (maximum days) 17 days. Furthermore, occurrence 96.67%, AH (CDHWs’ accumulated heat) had 97.78%, which, upon examination trend pattern, accounted for largest increase area. also found TAH average temperature anomalies, < −0.5) shows obvious seasonality, increases winter spring being significantly greater summer autumn. intensity stronger anomaly 0.4–0.8 °C, there north–south pattern across region. In northwestern Asia, (SPEI 15–30 per year average. During transition base period reference period, 25%, dry days prior decreased 7.35 conclusion our can provide theoretical basis coping climate change arid zones.

Language: Английский

Citations

19
Interannual variability of spring and summer monsoon growing season carbon exchange at a semiarid savanna over nearly two decades DOI Creative Commons
Russell L. Scott, Miriam R. Johnston, John F. Knowles

et al.

Agricultural and Forest Meteorology, Journal Year: 2023, Volume and Issue: 339, P. 109584 - 109584

Published: June 30, 2023

Language: Английский

Citations

11