Landscape Evolution, Soil Formation, and Ecological Patterns and Processes in Sonoran Desert Bajadas

1994 ◽  
Vol 64 (2) ◽  
pp. 111-148 ◽  
Author(s):  
Joseph R. McAuliffe
2019 ◽  
Vol 46 (2) ◽  
pp. 171-179 ◽  
Author(s):  
Emmeline N Topp ◽  
Jacqueline Loos

SummaryKnowledge of ecological patterns and processes is key to effective conservation of biodiversity hotspots under threat. Renosterveld is one of the most critically endangered habitats in the biologically unique Cape Floristic Region, South Africa. For the first time, we map and synthesize the current state of knowledge on renosterveld ecology and conservation. We investigated 132 studies for the themes, locations and taxa of renosterveld research and the fragmentation, threats, recommendations and barriers to renosterveld conservation. More studies focused on plants than any other taxa (48% of articles) and are conducted mostly in larger, intact renosterveld fragments. The most commonly identified threat to renosterveld was agricultural intensification; conservation recommendations spanned improved farming practices, formal protection and local patch management. Conservation implementation has been piecemeal and has depended largely on the goodwill of landowners, which can be constrained by costs of conservation measures and a lack of suitable restoration means. Citizen science is a promising potential solution to some barriers. Fragmented knowledge in such a transformed and relatively densely populated region highlights the scale of knowledge gaps for other biodiversity hotspots and has implications for ongoing conservation work.


2003 ◽  
Vol 47 (6) ◽  
pp. 17-24 ◽  
Author(s):  
I. Rodríguez-Iturbe

Ecohydrology is the science that studies the mutual interaction between the hydrological cycle and ecosystems. Such an interaction is especially intense in water-controlled ecosystems, where water may be a limiting factor, not only because of its scarcity, but also because of its intermittent and unpredictable appearance. Hydrologic dynamics is shown to be a crucial factor for ecological patterns and processes. The probabilistic structure of soil moisture in time and space is presented as the key linkage between soil, climate and vegetation dynamics. Nutrient cycles, vegetation coexistence and plant response to environmental conditions are all intimately linked to the stochastic fluctuation of the hydrologic inputs driving an ecosystem.


CATENA ◽  
2015 ◽  
Vol 128 ◽  
pp. 63-79 ◽  
Author(s):  
Hans Jäger ◽  
Matthias Achermann ◽  
Jarosław Waroszewski ◽  
Cezary Kabała ◽  
Małgorzata Malkiewicz ◽  
...  

2002 ◽  
Vol 59 (8) ◽  
pp. 1418-1427 ◽  
Author(s):  
W Gregory Hood

The use of hydraulic geometry and other geomorphic indices has been recommended for habitat restoration and creation of estuarine tidal channels. Although such an approach provides design guidance for tidal channel form, it does not provide guidance for the ecological consequences of channel form. This study investigates the potential linkage of the scaling of tidal channel form with ecological patterns and processes in estuarine tidal channels of the lower Chehalis River, Washington, U.S.A. Ebb tide surface velocity was related to channel size, as was exit time and export probability of tiny drogues, which mimic floating allochthonous detritus. Consequently, the amount of organic material in channel sediments scaled negatively with channel size as did the abundance of benthic surface deposit feeders. These observations suggest that the highest concentrations of fish feeding in estuarine tidal channels may be in smaller channels or in the smaller and more distal portions of large channels. Scaling of ecological patterns and processes with tidal channel size may be an example of a more general ecological scaling with landscape form, i.e., landscape allometry.


2010 ◽  
Vol 61 (8) ◽  
pp. 864 ◽  
Author(s):  
Fran Sheldon ◽  
Christine S. Fellows

Water quality, along with hydrology, plays an important role in the spatial and temporal dynamics of a range of ecological patterns and processes in large rivers and is also often a key component of river health assessments. Geology and land use are significant drivers of water quality during flow periods while during periods of no-flow, local-scale factors such as evaporation, groundwater influence and the concentration and precipitation of compounds are important. This study explored the water quality changes in two Australian dryland rivers, the Cooper Creek (Lake Eyre Basin) and the Warrego River (Murray–Darling Basin), across different hydrological phases over several years. Water quality varied both spatially and temporally; the greatest spatial variability occurred during the no-flow phase, with temporal changes driven by flow. Concentrations of major anions and cations also varied spatially and temporally, with an overall cation dominance of calcium and magnesium and an anion dominance of bicarbonate. This bicarbonate dominance contrasts with previous data from inland lentic systems where sodium chloride was found to dominate. Such extreme spatial and temporal variability hampers successful derivation of water quality guidelines for these variable rivers and suggests such guidelines would need to be developed with respect to ‘flow phase’.


2014 ◽  
Vol 12 (1) ◽  
pp. 5-14 ◽  
Author(s):  
James B Heffernan ◽  
Patricia A Soranno ◽  
Michael J Angilletta ◽  
Lauren B Buckley ◽  
Daniel S Gruner ◽  
...  

2020 ◽  
Author(s):  
Sara Snell Taylor ◽  
Jessica R. Coyle ◽  
Ethan P. White ◽  
Allen H. Hurlbert

AbstractTransient species, which do not maintain self-sustaining populations in a system where they are observed, are ubiquitous in nature and their presence often impacts the interpretation of ecological patterns and processes. Identifying transient species from temporal occupancy, the proportion of time a species is observed at a given site over a time series, is subject to classification errors as a result of imperfect detection and source-sink dynamics. We use a simulation-based approach to assess how often errors in detection or classification occur in order to validate the use of temporal occupancy as a metric for inferring whether a species is a core or transient member of a community. We found that low detection increases error in the classification of core species, while high habitat heterogeneity and high detection increase error in classification of transient species. These findings confirm that temporal occupancy is a valid metric for inferring whether a species can maintain a self-sustaining population, but imperfect detection, low abundance, and highly heterogeneous landscapes may yield high misclassification rates.


2019 ◽  
Author(s):  
W. Marijn van der Meij ◽  
Arnaud J. A. M. Temme ◽  
Jakob Wallinga ◽  
Michael Sommer

Abstract. Humans have substantially altered soil and landscape patterns and properties due to agricultural use, with severe impacts on biodiversity, carbon sequestration and food security. These impacts are difficult to quantify, because we lack data on long-term changes in soils in natural and agricultural settings and available simulation methods are not suitable to reliably predict future development of soils under projected changes in climate and land management. To help overcome these challenges, we developed the HydroLorica soil-landscape evolution model, that simulates soil development by explicitly modelling the spatial water balance as driver of soil and landscape forming processes. We simulated 14500 years of soil – formation under natural conditions for three scenarios of different rainfall inputs. For each scenario we added a 500-year period of intensive agricultural land use, where we introduced tillage erosion and changed vegetation type. Our results show substantial differences between natural soil patterns under different rainfall input. With higher rainfall, soil patterns become more heterogeneous due to increased tree throw and water erosion. Agricultural patterns differ substantially from the natural patterns, with higher variation of soil properties over larger distances and larger correlations with terrain position. In the natural system, rainfall is the dominant factor influencing soil variation, while for agricultural soil patterns landform explains most of the variation simulated. The cultivation of soils thus changed the dominant factors and processes influencing soil formation, and thereby also increased predictability of soil patterns. Our study highlights the potential of soil-landscape evolution modelling for simulating past and future developments of soil and landscape patterns. Our results confirm that humans have become the dominant soil forming factor in agricultural landscapes.


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