Ecological Exchanges Research Articles

Edible Garden Cities: Rethinking Boundaries and Integrating Hedges into Scalable Urban Food Systems

Connecting to and extending recent debates around more-than-human thinking, this paper explores how porous boundary treatments and plot layouts might encourage ecological exchanges within new urban and peri-urban developments. This study therefore responds to suggestions for innovative plot designs that facilitate positive trans-species interactions, especially considering wider anxieties surrounding biodiversity loss and recognition of the need for climate-resilient garden spaces. Focusing on a recent example of a large-scale residential development in the English midlands, this paper outlines the socio-economic, cultural and ecological significance of embedding different hedgerow designs into early planning considerations; revealing the need to move beyond current models. The discussion then turns to how such ambitions might encourage sustainable land use, particularly through creating potentially scalable urban agricultural systems that sustain healthy food choices.

Spatial matching and value transfer assessment of ecosystem services supply and demand in urban agglomerations: A case study of the Guangdong-Hong Kong-Macao Greater Bay area in China

Due to the high intensity of urban construction and human intervention, the imbalance between ecosystem service supply and demand (ESSD) in urban agglomerations is deteriorating. The quantitative study of ecosystem service flow (ESF), as a critical process connecting ESSD, can assist decision-makers in accurately identifying the potential for ecological cooperation among cities, solving the conflict between ESSD in urban agglomerations, promoting regional ecological integration, and achieving sustainable and healthy development. Currently, quantitative research on ESF is focused chiefly on flow direction identification. However, the relationship between ESSD and ESF, flow scope, path, and rate measurement, are still in the exploratory stage. Using the Guangdong-Hong Kong-Macao Greater Bay Area (GBA) as an example, this paper evaluated the four ESSDs based on the InVEST model: habitat quality (HQ), carbon storage (CS), water yield (WY), and soil retention (SR), and quantified the comprehensive economic value of the four ESSDs using the alternative cost method with the city/county as the basic units. Finally, utilizing the breakpoint model and the field intensity model, we built an ESF value transfer model and estimated the value of ESFs transmitted from ESSD surplus cities/counties to the deficit in the GBA. The findings revealed an imbalance between ESSD in the GBA, with most of them being in severe ESSD deficit or surplus, and ESFs had played a key role in improving this. The primary transfer out locations (TOL) of ESFs were Huizhou, Zhaoqing, and Jiangmen. In contrast, the primary transfer in locations (TIL) of ESFs were Guangzhou, Shenzhen, Foshan, and other highly urbanized areas. The total value of ESFs in the GBA was as high as 4.218 billion yuan. As an attempt toward quantifying the ESF, this work provides a framework for the future establishment of scientific ecological compensation norms for urban agglomerations to encourage benign and equitable ecological exchanges between cities/counties.

Las colonias francesas dentro de la ecología-mundo (1830-1962): el caso de los combustibles fósiles, los bosques y las plantaciones tropicales en Argelia y Vietnam

Los imperios coloniales jugaron un papel importante en la historia del Capitaloceno a través de la apropiación y explotación de los recursos naturales baratos, de la mano de obra y las energías baratas del mundo extraeuropeo, pero también por su producción de las naturalezas capitalizadas dentro de él, y, más ampliamente su coproducción de un mundo ecológico caracterizado por intercambios económicos y ecológicos desiguales a escala global. Basado en una problemática resultante del trabajo de Jason Moore, una reinterpretación de la historiografía existente y un trabajo de archivo, este artículo muestra que, si bien es esclarecedor comprender la historia de los combustibles fósiles, los bosques y las plantaciones de Argelia (1830-1962) y de Vietnam (1858-1954) en términos de ecología-mundo, su contribución al desarrollo de la ecología-mundo debe examinarse a la luz de las especificidades de cada colonia y de cada sector. En primer lugar, hay que matizar la hipótesis de una producción colonial de combustibles fósiles que sería sistemáticamente barata y destinada a los centros capitalistas occidentales de la ecología-mundo, no correspondiendo esta hipótesis ni al carbón argelino (caro y usado localmente) ni a los hidrocarburos argelinos (caros y exportados principalmente a Francia) ni al carbón vietnamita (barato pero exportado al sudeste asiático). Entonces, la historia conjunta de las plantaciones de caucho vietnamitas y la agricultura colonial argelina revela una capacidad desigual y nunca absoluta de los colonizadores franceses, siempre dependientes de las condiciones ecológicas locales, para crear naturalezas capitalizadas que generen productos tropicales baratos. Finalmente, el estudio combinado de la explotación colonial de los recursos forestales en Argelia y Vietnam permite mostrar hasta qué punto el ecologismo manifestado por los colonizadores franceses, en particular el de las administraciones forestales coloniales, no obstaculizó la producción. Para la ecología-mundo, este análisis, evidentemente, merecería ser profundizado por nuevos estudios de caso, pero constituye, sin embargo, un primer vistazo a la compleja inserción histórica de las colonias francesas en el mundo ecológico.

The effect of tourism on teleconnected ecosystem services and urban sustainability: An emergy approach

Tourism plays an increasingly critical role in national and urban economies. While tourist spending particularly benefits urban economies, the growth of urban tourism has gradually intensified cities’ reliance on external resources and significantly influenced resource-supplying areas. This study adopts the concept of urban land teleconnections (ULTs) to discuss how the cultural ecosystem services in the tourism industry have affected distant areas in general and how the increased tourist flow has intensified Taipei's dependence on external resources and challenged its urban sustainability in particular. An emergy-based analysis is conducted to evaluate the contribution of material flows triggered by urban tourism into the urban ecological-economic system and to demonstrate how urban tourism has increased the city's reliance on external distant areas. The analysis highlights the biophysical value created by external resources in the economic system. Driven by growing urban tourism during 2000–2016, Taipei witnessed considerable material inflow, including construction materials for newly built hotels, gasoline for sightseeing buses, food for tourists, and money through retail consumption. These material inflows are converted into emergy flows to analyze the effects of tourism-driven material flows on urban sustainability. The results show that emergy inflows driven by urban tourism considerably increased the flow of construction materials needed to build hotels to meet tourists’ accommodation needs. As a result, the total emergy driven by Taipei tourism increased fifteen-fold since 2000 and crested in 2015. However, the demand for tourism-related resources triggered changes in land use and land cover in distant resource-supplying areas. Such ULTs further contributed to unequal ecological exchanges. Our findings highlight the need for urban sustainability assessments to account for the impact of ULTs driven by urban tourism on distant resource-supplying areas. In addition, tourism planning and management should not be a facet but a core element of urban planning objectives.

Peri-urbanization, land teleconnections, and the equality of ecological exchange: An emergy approach

Urbanization is not only accompanied by local land use change, but also causes land use changes in distant places and affects the socio-ecological systems there. Urban land teleconnections (ULT) was introduced as a conceptual framework to link urbanization and land use changes of distant areas in the past, which have been generally ignored. ULT has also been proposed for use in investigating the equity principle of urban sustainability. The unequal exchange between an urban system and distant areas could become underlying causes that result in land use change in distant areas in the future. This study provides two case studies to demonstrate how land use processes are connected through peri-urbanization of Taipei and its resource inflow areas and the implications of the equality of ecological exchanges are discussed. The first case considers vegetable and fruit products from Changhua, Yunlin, and Chiayi Counties (the Chang-Yun-Chia area) of central and southern Taiwan, and the second case considers cement from Hualien in eastern Taiwan. To implement analysis of ULT, emergy synthesis was used to quantify the flow of materials between Taipei and the distant areas providing raw materials for food and construction and to assess the fairness and equality of the exchange. The results indicate that agricultural products or cement from distant areas tend to have low emergy exchange ratios when sold to Taipei markets. This phenomenon results from the fact that money is paid for human services and not for the work of nature that made the products. The low emergy exchange ratio of agricultural products caused land conversion in the Chang-Yun-Chia area. The low emergy exchange ratio of cement not only hurt the local economy of Hualien, because when it is exchanged more emergy of cement leaves the region than is returned in the buying power of the money received for it. Further inequality results, because the high environmental loading of cement extraction impacts the local Hualien system. Using empirical research on the application of the ULT theory to regional/local levels, the impact of the Taipei Metropolitan Area on the Chang-Yun-Chia and Hualien areas not only verifies the Taipei’s ULT phenomenon, but also clarifies the research gaps in the application of ULT theory.

The Arboreal Empire and the ‘Parliament of Things’: Australian Trees in Colonial South India

Abstract In the second half of the nineteenth century India and Australia were linked through a series of ecological exchanges, among the most important of which was the introduction of such Australian trees as eucalyptus, casuarina and acacia. South India was particularly affected by these importations, especially the Nilgiri hills, a plausible ‘neo-Europe’. But, contrary to A.W. Crosby’s argument about ‘ecological imperialism’, many of these introductions relied heavily on calculated human agency and transoceanic networks of foresters and horticulturalists for their success; other attempted transfers either failed or took off in unpredictable ways. The motives behind the introduction of Australian tree species varied but included the acute shortage of fuelwood in south India, colonial landscape aes- thetics, an ideology of ‘improvement’ and belief in the transferability of species within the same temperate or tropical climatic zone. By 1914 experience had revealed the complexity of these ecological exchanges and their limitations, as well as the ability of some introduced species to become ‘wild’ and ‘invasive’.

Construction of ecological security pattern based on habitat quality in Tang County, Hebei, China.

As the key and hot topic in landscape ecology, ecological security pattern plays an important role in maintaining regional ecological security and achieving regional sustainable development. Based on land use data of 2016, we used the InVEST model to evaluate the habitat quality of Tang County to determine the ecological source. The resistance surface was constructed by selecting the resistance factors such as land use type, habitat quality index, vegetation coverage, distance to water, distance to settlements, distance to roads, with the resistance threshold being used to partition the ecological security pattern. Finally, the ecological security pattern of Tang County was constructed by determining the ecological corridor with the MCR model. The results showed that the ecological source of Tang County accounted for 3.3% of the total area, mainly distributed in forest land and waters with large plaque area, and the Western Ocean Reservoir (one of the four major reservoirs in Hebei Province). According to the cost resistance mutation point, the research region could be divided into prohibited development zone, restricted development zone, optimized development zone, and key development zone. The percentage of each zone was 18.9%, 43.6%, 27.6% and 9.9%, respectively. The total length of the potential ecological corridors in Tang County was 333.52 km, and was 263.91 km after optimization, which was helpful for various ecological exchanges. Our results had important guiding significance for the rational and sustainable use of land resources in Tang County, and could provide theoretical and technical supports for the decision-making of land planning and layout in Tang County.

Modelling Multi-regional Ecological Exchanges: The Case of UK and Africa

As environmental impacts continue to rise, the need to identify and quantify the underlying causes of these impacts has prompted important research questions. This is heightened by the fact that the production of goods and services is becoming increasingly global with countries relying on each other through trade. As such, it is important to have a mechanism in place to understand the environmental burden shifts from one country to another. To this end, this paper exploits a paradox in global environmental analysis, which stems from a false decoupling between economic and production systems as observed in most developed nations, which results in improved territorial emissions of these developed countries at the expense of developing countries.Ecological unequal exchange is one such contemporary ecological economic concept that is used to highlight such asymmetric transfer of embodied natural resources and biophysical indicators between countries. Attempts at environmental impacts reduction efforts has largely focused on carbon emissions but given the complex supply chain created through globalisation and international trade, it is important to consider other important metrics such as land and water use alongside carbon emissions to drive environmental policies that will holistically address ecologically unequal exchanges. For developing countries in Africa where the dependence on land use and water use for agricultural activities are crucial to the development of national economies and in combating poverty, an assessment of these metrics has become even more paramount.Against this backdrop, the current work draws upon the theoretical constructs of multi-regional input-output (MRIO) framework to trace country specific sectorial-level flows of the aforementioned metrics between a representative developed nation, UK, and 27 African regions in order to fully examine their ecological exchanges. Key findings in the study suggest that for water consumption and land use, there is a net externalisation of these impacts for all the 27 African regions by the UK. It was also determined that the extent of the imbalance between the UK and the African region is exceedingly far greater for water consumption. It is recommended that in formulating a robust multi-national environmental policy where so many factors are at play, country specific and industry targeted approach to ecological unequal exchange between nations provides better and improved insight into addressing ensuing environmental issues.

On the relationship between ocean DMS and solar radiation

[1] Biologically produced dimethylsulfide (DMS) is an important source of sulfur to the marine atmosphere that may affect cloud formation and properties. DMS is involved in a complex set of biochemical transformations and ecological exchanges so its global distribution is influenced by numerous factors, including oxidative stress from UV radiation. We re-examine correlations between global surface DMS concentrations and mixed layer solar radiation dose (SRD), and find that SRD accounts for only a very small fraction (14%) of total variance in DMS measurements when using minimal aggregation methods. Moreover this relationship arises in part from the fact that when mixed layers deepen, both SRD and DMS decrease. When we control for this confounding effect, the correlation between DMS and SRD is reduced even further. These results indicate that factors other than solar irradiance play a leading role in determining global DMS emissions.

Navegando contra a corrente: o papel dos escravos e da flora africana na botânica do período colonial

O caráter revolucionário das trocas ecológicas e botânicas que sucederam a expansão marítima Européia pós 1492 é hoje largamente reconhecido. Não obstante, a literatura que estuda as trocas culturais e comerciais do período pós-Colombiano permanece omissa no que se refere à disseminação alhures de plantas nativas da África e aos meios pelos quais isto ocorreu. Para reverter esta corrente, como revela este artigo, torna-se necessário que se caracterize o papel que o comércio transatlântico de escravos teve na dispersão destas plantas, assim como a importância que os escravos africanos desempenharam na consolidação de gêneros alimentícios básicos da culinária das Américas. Ao dar destaque à diáspora africana, enquanto um fenômeno que envolve tanto pessoas quanto plantas, coloca-se ênfase nos sistemas primitivos de conhecimento africano. A expressão destes sistemas de conhecimento na coesão de comunidades inteiras de africanos reflete formas particulares de relações de poder, preferências alimentares, identidade cultural, e disputas sobre o processo de trabalho. Ao dar relevo às plantas africanas estabelecidas nas Américas, este artigo procura corrigir uma distorção comum em narrativas sobre as trocas transatlânticas: a insistência em enfatizar o papel dos europeus na disseminação de plantas a nível intercontinental e em valorizar produtos agrícolas de origem Ameríndia e Asiática em detrimento da contribuição africana. O objetivo deste trabalho é promover o resgate histórico do papel da África na botânica colonial.

The archaeology of the Spanish contact period in the Caribbean

The arrival of Spanish conquistadors and colonists to the Caribbean in the late fifteenth century set in motion the processes that produced the post-1500 “New World.” The sixteenth-century cultural and ecological exchanges among Europe, Africa, and the Americas that took place during the early contact period greatly affected the social and economic patterns of life in both the Old and the New Worlds. Nowhere was this change manifest as profoundly and dramatically as in the sixteenth-century Caribbean. This essay explores the archaeological insights into the processes of encounter between the Amerindian peoples of the Caribbean region and the first permanent Europeans in the Americas and the responses of each to contact with the other. Archaeological research has informed our understanding of this seminal era in New World cultural development in important ways. It had also allowed the documentation of both the cultural and demographic disintegration of the Caribbean Indians and the formation of Euro-American culture.