Using embodied HANPP to analyze teleconnections in the global land system: Conceptual considerations

Geografisk Tidsskrift—Danish Journal of Geography 109(2):119–130, 2009

In our rapidly globalizing world economy activities in one region have increasingly important effects on ecological, economic or social processes elsewhere, an effect which we here denote as ‘teleconnections’ between different regions. Biomass trade, one of the causes behind such teleconnections, is currently growing exponentially. Integrated analyses of changes in the global land system are high on the agenda of sustainability science, but a methodological framework for a consistent allocation of environmental burdens related to the consumption and production of biomass between regions has not been put forth to date. The concept of the ‘embodied human appropriation of net primary production’ (abbreviated ‘embodied HANPP’ or ‘eHANPP’) allows for the assessment of the ‘upstream’ effects on ecosystem energetics associated with a particular level of biomass consumption or with a given biomass-based product. This concept is based on HANPP and its two components: (1) productivity changes resulting from land conversion (ΔNPP_LC), and (2) harvest of biomass in ecosystems (NPP_h). HANPP, defined as the sum of ΔANPP_LC and NPP_h in any given territory, is indicative of the intensity with which humans use the land for their purposes. eHANPP is defined as the NPP appropriated in the course of biomass production, encompassing losses along the production chain as well as productivity changes induced through land conversion or harvest. By making the pressure exerted on ecosystems associated with imports and exports visible, eHANPP allows for the analysis of teleconnections between producing and consuming regions. This article puts forward the eHANPP concept, illustrates its utility for integrated socioecological land-change research based on top-down data on global HANPP and biomass consumption, and discusses the possibilities and challenges related to its quantification in bottom-up approaches.     

Predicting the impact of land use on the major element and nutrient fluxes in coastal Mediterranean rivers: The case of the Têt River (Southern France)

This study presents a detailed discrimination between the natural and anthropogenic sources of dissolved major elements in the Têt River, a typical small coastal river in the south of France. The main objectives were to quantify the materials that were released by human activities in the basin, and to determine the specific element inputs for the major land use forms. The dissolved material fluxes were estimated by weekly monitoring over a hydrological year (2000–2001) along the major water gauging stations, and the flux relationships were examined in the context of anthropogenic and natural basin characteristics as determined by a Geographical Information System (GIS). Intensive agricultural land use in the form of fruit tree cultures and vineyards has a strong control on the dissolved element fluxes in the river. Area specific element releases for these cultures are greatest for SO₄, with an estimated average of about 430 ± 18 keq km⁻² a⁻¹. This is ?11 times the natural SO₄ release by rock weathering. Also for K, NO₃, PO₄ and Mg, the specific releases were ?6 times the natural weathering rates (respectively about 44, 60, 4 and 265 keq km⁻² a⁻¹). Waste-waters are the other major source of anthropogenic elements in the river. They have an important role for the fluxes of inorganic P and N, but they are also a considerable source of Cl and Na to the river. For example, the average annual release of Cl is around 150 moles/inhabitant in the rural basin parts. Further downstream, however, where population density strongly increases, industrial effluents can enhance this value (>300 moles/inhabitant). The waste-waters contribute more than 70% of the dissolved inorganic N export to the sea, although their contribution to the average DOC export is almost negligible (3%).     

Soil particle size distribution and induced soil carbon transport by ephemeral gully erosion in Mediterranean mountain arable land

In Mediterranean mountain agroecosystems, soil erosion associated with the development of ephemeral gullies is a common environmental problem that contributes to a loss of nutrient-rich topsoil. Little is known about the influence of ephemeral gully erosion on particle size distribution and its effect on soil organic (SOC) and inorganic (SIC) carbon among different sized soil particles in agricultural soils. In this study, laboratory tests were conducted using velocity settling tube experiments to examine the effects of erosion on sediment particle size distributions from an incised ephemeral gully, associated with an extreme event (235 mm). We also consider subsequent deposition on an alluvial fan in order to assess the distribution of SOC and SIC concentrations and dissolved carbon before and after the extreme event. Soil fractionation was carried out on topsoil samples (5 cm) collected along an ephemeral gully in a cultivated field, located in the lower part of a Mediterranean mountain catchment. The results of this study showed that the sediment transported downstream by runoff plays a key role in the particle size distribution and transportability of soil particles and associated carbon distribution in carbonate rich soils. The eroding sediment is enriched in clay and silt-sized particles at upslope positions with higher SOC contents and gradually becomes coarser and enriched in SIC at the end of the ephemeral gully because the finest particles are washed-out of the study field. The extreme event was associated with an accumulation of dissolved organic carbon at the distal part of the depositional fan. Assessment of soil particle distribution using settling velocity experiments provides basic information for a better understanding of soil carbon dynamics in carbonate rich soils. Processes of soil and carbon transport and relationships between soil properties, erodibility and aggregate stability can be helpful in the development of more accurate soil erosion models. © 2019 John Wiley & Sons, Ltd. © 2019 John Wiley & Sons, Ltd.     

The Rila-Pastra Normal Fault and multi-stage extensional unroofing in the Rila Mountains (SW Bulgaria)

The Rhodope Metamorphic Province represents the core of an Alpine orogen affected by strong syn- and postorogenic extension. We report evidence for multiple phases of extensional unroofing from the western border of the Rila Mountains in the lower Rila valley, SW Bulgaria. The most prominent structure is the Rila-Pastra Normal Fault (RPNF), a major extensional fault and shear zone of Eocene to Early Oligocene age. The fault zone includes, from base to top, mylonites, ultramylonites and cataclasites, indicating deformation under progressively decreasing temperature, from amphibolite-facies to low-temperature brittle deformation. It strikes E–W with a top-to-the-N-to NW-directed sense of shear. Basement rocks in the hanging wall and footwall both display amphibolite-facies conditions. The foliation of the hanging-wall gneisses, however, is discordantly cut by the fault, while the foliation of the footwall gneisses is seen to curve into parallelism with the fault when approaching it. Two ductile splays of the RPNF occur in the footwall, which are subparallel to the foliation of the surrounding gneisses and merge laterally into the mylonites of the main fault zone. The concordance between the foliation in the footwall and the RPNF suggests that deformation and cooling in the footwall occurred simultaneously with extensional shearing, while the hanging-wall gneisses had already been exhumed previously. The RPNF is associated with thick deposits of an Early Oligocene, syntectonic breccia on top of its hanging wall. Integrating our results with previous studies, we distinguish the following stages of extensional faulting: (1) Late Cretaceous NW–SE extension (Gabrov Dol Detachment), exhumation of the present day hanging wall of the RPNF; (2) Eocene to Early Oligocene NW–SE to N–S extension (RPNF); (3) Miocene to Pliocene E–W extension (Western Border Fault), formation of the Djerman Graben; (4) Holocene to recent N–S to NW–SE extension (Stob Fault), reactivating the SW part of the Western Border Fault.     

Long-term statistics of potentially hazardous sea states in the North Sea 1958–2014

Significant wave height and mean wave period are two of the most commonly used parameters to describe wave climate, wave climate variability, and their potential long-term changes. While these parameters are generally useful to characterize the distribution of waves within a given sea state, they provide less information about potentially high-risk situations. Over the recent years, a number of criteria were suggested that are considered to better characterize high-risk situations and which could bear a potential for the development of safety warning indices. Based on a multi-decadal high-resolution wind-wave hindcast, a climatology of such parameters is developed for the North Sea covering the years 1958–2014. More specifically, average conditions, inter-annual variability and long-term changes for unusually steep, rapidly developing and crossing sea states are considered. Generally, there are pronounced spatial variations in the frequency of such sea states, while over time, there is some seasonal and inter-annual variability but no substantial long-term trend could be identified.     

Proposal for International Agreement on Ca Notation Resulting from Discussions at Workshops on Stable Isotope Measurements Held in Davos (Goldschmidt 2002) and Nice (EGS-AGU-EUG 2003)

A proposal is made to standardise the reporting of Ca isotope data to the δ⁴⁴Ca/⁴⁰Ca notation (or δ⁴⁴Ca/42Ca) and to adopt NIST SRM 915a as the reference standard.     

Strontium as a tracer of weathering processes in a silicate catchment polluted by acid atmospheric inputs, Strengbach, France

This paper determines the weathering and atmospheric contributions of Ca in surface water from a small spruce forested silicate catchment (N–E France) receiving acid atmospheric inputs. The bedrock is a granite with K-feldspar and albite as dominant phases. The calcium content in plagioclase is low and the Ca/Na ratio in surface water is high, reflecting other sources of calcium from those expected from the weathering of major mineral phases. The biotite content is low. Only traces of apatite were detected while no calcite was found in spite of a major hydrothermal event having affected the granite. The strontium isotopic ratio ⁸⁷Sr/⁸⁶Sr and Sr content was used as a tracer of weathering and was determined in minerals and bulk bedrock, open field precipitation, throughfall, soil solution, spring and stream water. The Sr isotopic ratio of the reacting weathering end-member was predicted by simulating the alteration of the granite minerals by incorporating strontium into the water–rock interaction kinetic code KINDIS. In the early stages of water–rock interaction, K-feldspar and biotite strongly influence the isotopic composition of the weathering solution whereas, the Na-rich plagioclase appears to be the main long-term reactive weathering end-member. Approximately 50% of dissolved Sr in streamwater are atmospherically derived. The ⁸⁷Sr/⁸⁶Sr ratios of exchangeable Sr in the fine fraction at 1-m depth from a soil profile indicate that the amount of exchangeable Sr seems essentially controlled by atmospheric inputs. The exception is the deep saprolite where weathering processes could supply the Sr (and Ca). Na-Plagioclase weathering obviously control the chemistry and the isotopic composition of surface waters. The weathering of trace mineral plays a secondary role, the exception is for apatite when plagioclase is absent. Our hydrochemical, mineralogical and isotopic investigations show that a major part of the strong Ca losses detected in catchment hydrochemical budgets that result from the neutralization of acid precipitation has an atmospheric origin. Consequently, in the long term, in such areas, the availability of such an exchangeable base cation might be strongly limited and surface waters consequently acidified.     

Divergent distributions of prey and predator,a fishing effect?

To compare the vertical distributions of benthos and fish species of Upper Lake Constance (Bodensee), 552 benthos samples were taken with an Auerbach grab at four transects (10–250 m). An additional 54 samples (1–10 m) were collected elsewhere. Complementary data was taken from the literature. In winter, most fish feed on benthos, mainly chironomids, but in summer less than 5% do so. Formerly the bottom gill-netting aimed mainly at catchingCoregonus pidschian, but it now aims atPerca fluviatilis. Contrary to expectation, in winter the greatest abundance ofP. fluviatilis is much deeper (55 m) than that of its preferred food, i.e. chironomids (<20 m). Comparably,C. pidschian also stayed deeper than its main food source (chironomids and mollusks).Lota lota, Salvelinus profundus andS. alpinus — unlike the unwanted cyprinids — also stay or stayed deeper than the attractive chironomids. It is argued that the fish reduce their predation risk, i.e. the risk of being gillnetted in the upper 50 m, by selecting the deeper less dangerous, but also less food-abundant habitat. Balancing predation risk against food abundance may have led to survival of the deepest.