scholarly journals Patch-scale to hillslope-scale geodiversity alleviates susceptibility of dryland ecosystems to climate change: insights from the Israeli Negev

2021 ◽  
Vol 50 ◽  
pp. 129-137
Author(s):  
Ilan Stavi ◽  
Hezi Yizhaq ◽  
Amir Szitenberg ◽  
Eli Zaady
Keyword(s):  
Climate Change ◽  
Dryland Ecosystems ◽  
Hillslope Scale ◽  
Patch Scale

scholarly journals Global ecosystem thresholds driven by aridity

Science ◽  
2020 ◽  
Vol 367 (6479) ◽  
pp. 787-790 ◽  
Author(s):  
Miguel Berdugo ◽  
Manuel Delgado-Baquerizo ◽  
Santiago Soliveres ◽  
Rocío Hernández-Clemente ◽  
Yanchuang Zhao ◽  
...  
Keyword(s):  
Climate Change ◽  
Ecosystem Services ◽  
Soil Fertility ◽  
Plant Cover ◽  
Plant Productivity ◽  
Abrupt Changes ◽  
Dryland Ecosystems ◽  
Negative Impacts ◽  
Ecosystem Changes ◽  
Three Phases

Aridity, which is increasing worldwide because of climate change, affects the structure and functioning of dryland ecosystems. Whether aridification leads to gradual (versus abrupt) and systemic (versus specific) ecosystem changes is largely unknown. We investigated how 20 structural and functional ecosystem attributes respond to aridity in global drylands. Aridification led to systemic and abrupt changes in multiple ecosystem attributes. These changes occurred sequentially in three phases characterized by abrupt decays in plant productivity, soil fertility, and plant cover and richness at aridity values of 0.54, 0.7, and 0.8, respectively. More than 20% of the terrestrial surface will cross one or several of these thresholds by 2100, which calls for immediate actions to minimize the negative impacts of aridification on essential ecosystem services for the more than 2 billion people living in drylands.

scholarly journals An ecohydrological approach to predicting hillslope-scale vegetation patterns in dryland ecosystems

2012 ◽  
Vol 48 (1) ◽  
Author(s):  
Trenton E. Franz ◽  
Kelly K. Caylor ◽  
Elizabeth G. King ◽  
Jan M. Nordbotten ◽  
Michael A. Celia ◽  
...  
Keyword(s):  
Vegetation Patterns ◽  
Dryland Ecosystems ◽  
Hillslope Scale

scholarly journals TopoCLIM: Rapid topography-based downscaling of regional climate model output in complex terrain v.1.0

2021 ◽  
Author(s):  
Joel Fiddes ◽  
Kristoffer Aalstad ◽  
Michael Lehning
Keyword(s):  
Climate Change ◽  
Land Surface ◽  
Complex Terrain ◽  
Climate Model ◽  
Regional Climate ◽  
Mapping Method ◽  
Swiss Alps ◽  
Regional Climate Model Output ◽  
Wide Range ◽  
Hillslope Scale

Abstract. This study describes and evaluates a new downscaling scheme that specifically addresses the need for hillslope scale atmospheric forcing time-series for modeling the local impact of regional climate change projections on the land surface in complex terrain. The method has a global scope and is able to generate the full suite of model forcing variables required for hydrological and land surface modeling at hourly timesteps. It achieves this by utilising the previously published TopoSCALE scheme (Fiddes et al. 2014) to generate a synthetic observation of current climate at hillslope scale while accounting for a broad range of surface-atmosphere interactions. These synthetic observations are then used to debias (downscale) CORDEX climate variables using the quantile mapping method. A further temporal disaggregation step produces sub-daily fields. This approach has the advantages of other empirical-statistical methods, namely speed of use while avoiding the need for ground data, which is often limited. It is therefore a suitable method for a wide range of remote regions where ground data is absent, incomplete, or not of sufficient length. The approach is evaluated using a network of high elevation stations across the Swiss Alps and a test application of modelling climate change impacts on Alpine snow cover is given.

scholarly journals Shifting species interactions in terrestrial dryland ecosystems under altered water availability and climate change

2011 ◽  
Vol 87 (3) ◽  
pp. 563-582 ◽  
Author(s):  
Kevin E. McCluney ◽  
Jayne Belnap ◽  
Scott L. Collins ◽  
Angélica L. González ◽  
Elizabeth M. Hagen ◽  
...  
Keyword(s):  
Climate Change ◽  
Water Availability ◽  
Species Interactions ◽  
Dryland Ecosystems

scholarly journals Mind the Gap! Reconciling Environmental Water Requirements with Scarcity in the Murray–Darling Basin, Australia

Water ◽  
2022 ◽  
Vol 14 (2) ◽  
pp. 208
Author(s):  
Matthew J. Colloff ◽  
Jamie Pittock
Keyword(s):  
Climate Change ◽  
Structural Adjustment ◽  
Environmental Water ◽  
Environmentally Sustainable ◽  
Decision Context ◽  
Consumptive Use ◽  
Murray Darling Basin ◽  
Dryland Ecosystems ◽  
Step Down ◽  
Policy Adjustments

The Murray–Darling Basin Plan is a $AU 13 billion program to return water from irrigation use to the environment. Central to the success of the Plan, commenced in 2012, is the implementation of an Environmentally Sustainable Level of Take (ESLT) and a Sustainable Diversion Limit (SDL) on the volume of water that can be taken for consumptive use. Under the enabling legislation, the Water Act (2007), the ESLT and SDL must be set by the “best available science.” In 2009, the volume of water to maintain wetlands and rivers of the Basin was estimated at 3000–7600 GL per year. Since then, there has been a steady step-down in this volume to 2075 GL year due to repeated policy adjustments, including “supply measures projects,” building of infrastructure to obtain the same environmental outcomes with less water. Since implementation of the Plan, return of water to the environment is falling far short of targets. The gap between the volume required to maintain wetlands and rivers and what is available is increasing with climate change and other risks, but the Plan makes no direct allowance for climate change. We present policy options that address the need to adapt to less water and re-frame the decision context from contestation between water for irrigation versus the environment. Options include best use of water for adaptation and structural adjustment packages for irrigation communities integrated with environmental triage of those wetlands likely to transition to dryland ecosystems under climate change.

scholarly journals Structural and functional connectivity as a driver of hillslope erosion following disturbance

2016 ◽  
Vol 25 (3) ◽  
pp. 306 ◽  
Author(s):  
C. Jason Williams ◽  
Frederick B. Pierson ◽  
Peter R. Robichaud ◽  
Osama Z. Al-Hamdan ◽  
Jan Boll ◽  
...  
Keyword(s):  
Functional Connectivity ◽  
Field Studies ◽  
Rainfall Simulation ◽  
Hydrologic Response ◽  
Hydrologic Modelling ◽  
Erosion Processes ◽  
Flow Formation ◽  
High Runoff ◽  
Hillslope Scale ◽  
Patch Scale

Hydrologic response to rainfall on fragmented or burnt hillslopes is strongly influenced by the ensuing connectivity of runoff and erosion processes. Yet cross-scale process connectivity is seldom evaluated in field studies owing to scale limitations in experimental design. This study quantified surface susceptibility and hydrologic response across point to hillslope scales at two degraded unburnt and burnt woodland sites using rainfall simulation and hydrologic modelling. High runoff (31–47 mm) and erosion (154–1893 g m–2) measured at the patch scale (13 m2) were associated with accumulation of fine-scale (0.5-m2) splash-sheet runoff and sediment and concentrated flow formation through contiguous bare zones (64–85% bare ground). Burning increased the continuity of runoff and sediment availability and yield. Cumulative runoff was consistent across plot scales whereas erosion increased with increasing plot area due to enhanced sediment detachment and transport. Modelled hillslope-scale runoff and erosion reflected measured patch-scale trends and the connectivity of processes and sediment availability. The cross-scale experiments and model predictions indicate the magnitude of hillslope response is governed by rainfall input and connectivity of surface susceptibility, sediment availability, and runoff and erosion processes. The results demonstrate the importance in considering cross-scale structural and functional connectivity when forecasting hydrologic and erosion responses to disturbances.

scholarly journals Spectral Diversity Successfully Estimates the α-Diversity of Biocrust-Forming Lichens

2019 ◽  
Vol 11 (24) ◽  
pp. 2942 ◽  
Author(s):  
Javier Blanco-Sacristán ◽  
Cinzia Panigada ◽  
Giulia Tagliabue ◽  
Rodolfo Gentili ◽  
Roberto Colombo ◽  
...  
Keyword(s):  
Climate Change ◽  
Species Richness ◽  
Diversity Index ◽  
Ecosystem Functions ◽  
Coefficient Of Determination ◽  
Support Vector ◽  
Α Diversity ◽  
Very High Spatial Resolution ◽  
Dryland Ecosystems ◽  
Spatio Temporal

Biocrusts, topsoil communities formed by mosses, lichens, liverworts, algae, and cyanobacteria, are a key biotic component of dryland ecosystems worldwide. Experiments carried out with lichen- and moss-dominated biocrusts indicate that climate change may dramatically reduce their cover and diversity. Therefore, the development of reproducible methods to monitor changes in biocrust diversity and abundance across multiple spatio-temporal scales is key for evaluating how climate change may impact biocrust communities and the myriad of ecosystem functions and services that rely on them. In this study, we collected lichen-dominated biocrust samples from a semi-arid ecosystem in central Spain. Their α-diversity was then evaluated using very high spatial resolution hyperspectral images (pixel size of 0.091 mm) measured in laboratory under controlled conditions. Support vector machines were used to map the biocrust composition. Traditional α-diversity metrics (i.e., species richness, Shannon’s, Simpson’s, and Pielou’s indices) were calculated using lichen fractional cover data derived from their classifications in the hyperspectral imagery. Spectral diversity was calculated at different wavelength ranges as the coefficient of variation of different regions of the reflectance spectra of lichens and as the standard deviation of the continuum removal algorithm (SD_CR). The accuracy of the classifications of the images obtained was close to 100%. The results showed the best coefficient of determination (r2 = 0.47) between SD_CR calculated at 680 nm and the α-diversity calculated as the Simpson’s index, which includes species richness and their evenness. These findings indicate that this spectral diversity index could be used to track spatio-temporal changes in lichen-dominated biocrust communities. Thus, they are the first step to monitor α-diversity of biocrust-forming lichens at the ecosystem and regional levels, a key task for any program aiming to evaluate changes in biodiversity and associated ecosystem services in drylands.

scholarly journals Response of Natural Vegetation to Climate in Dryland Ecosystems: A Comparative Study between Xinjiang and Arizona

2020 ◽  
Vol 12 (21) ◽  
pp. 3567
Author(s):  
Fang Zhang ◽  
Chenghao Wang ◽  
Zhi-Hua Wang
Keyword(s):  
Climate Change ◽  
Land Surface ◽  
Vegetation Index ◽  
Normalized Difference Vegetation Index ◽  
Natural Vegetation ◽  
Vegetation Growth ◽  
Climate Change And Variability ◽  
Changing Climate ◽  
Dryland Ecosystems ◽  
Background Climate

As one of the most sensitive areas to climate change, drylands cover ~40% of the Earth’s terrestrial land surface and host more than 38% of the global population. Meanwhile, their response to climate change and variability carries large uncertainties as induced by background climate, topography, and land cover composition; but there is a lack of intercomparison of different dryland ecosystems. In this study, we compare the changing climate and corresponding responses of major natural vegetation cover types in Xinjiang and Arizona, two typical drylands with similar landscapes in Asia and North America. Long-term (2002–2019) quasi-8-day datasets of daily precipitation, daily mean temperature, and Normalized Difference Vegetation Index (NDVI) were constructed based on station observations and remote sensing products. We found that much of Xinjiang experienced warming and wetting trends (although not co-located) over the past 18 years. In contrast, Arizona was dominated by warming with insignificant wetting or drying trends. Significant greening trends were observed in most parts of both study areas, while the increasing rate of NDVI anomalies was relatively higher in Xinjiang, jointly contributed by its colder and drier conditions. Significant degradation of vegetation growth (especially for shrubland) was observed over 18.8% of Arizona due to warming. Our results suggest that responses of similar natural vegetation types under changing climate can be diversified, as controlled by temperature and moisture in areas with different aridity.

scholarly journals Can Methane-Eating Bacteria in Drylands Help Us Reduce Greenhouse Gases?

2021 ◽  
Vol 9 ◽  
Author(s):  
Angela Lafuente ◽  
Concha Cano-Díaz
Keyword(s):  
Climate Change ◽  
Global Warming ◽  
Greenhouse Gases ◽  
Global Climate Change ◽  
Global Climate ◽  
The World ◽  
Dryland Ecosystems ◽  
Emission Of Greenhouse Gases

What is a dryland? The first thing that may come to your mind is a desert-like place where nothing can live or grow. Despite the scarcity of water, dryland ecosystems are diverse and will expand due to global climate change. The main cause of global warming is the increase of greenhouse gases in our atmosphere. To solve this, we obviously need to reduce the emission of greenhouse gases, but the study of microorganisms in nature also gives us exciting clues for how to address the problem of global warming. Microorganisms live in all possible Earth environments, and luckily some of them can even take greenhouse gases from the air as their food! In this article, we describe our search of the global soils for bacteria that can consume one of the most powerful greenhouse gases, methane (CH4). Contrary to what was expected, we found that these bacteria live in drylands all over the world!

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