Changes to Ecosystems
Changes to ecosystems refer to alterations in the structure and function of natural environments, often resulting from human activities or natural events. These changes can include shifts in species composition, disruptions to food webs, and modifications to physical landscapes. They can have significant impacts on biodiversity, ecological processes, and the services that ecosystems provide to humans.
5 Key excerpts on "Changes to Ecosystems"
eBook - ePub- Simon Bell(Author)
- 2012(Publication Date)
- Routledge(Publisher)
...Introduction The previous chapter showed how climate, particularly the aftereffects of the last (but probably not the final) glaciations, has driven and continues to drive many changes occurring in the landscape. The landform patterns and processes which are the subject of this chapter are no exception to this, and in fact in them we can see both the results of climatic processes and their continuing role in modifying climatic processes in the short to medium term, such as volcanic eruptions throwing gas and dust into the atmosphere. The structure and processes of geology supply the basic underlying layer or substrate upon which all terrestrial life and human activities rely. Geology interacts directly with climate to maintain a continuously dynamic state. However, the rates of geological change are generally so slow that for most ecological processes, or considerations for human use, it supplies a relatively stable framework and sets limits or boundary conditions. Areas of ancient shield rocks, where erosion is extremely slow, possess extremely stable geologies. There are places in which dramatic processes occur reasonably frequently, notably in regions with active volcanoes and earthquakes, where processes can disturb and modify ecological or cultural patterns quite dramatically, and occasionally disastrously for anyone living there. It is not the purpose of this chapter to provide a primer on geology, geomorphology or hydrology; instead it is to interpret what we perceive in this field in terms of the patterns and processes, insofar as they help us to read the landscape and to give us a basis for understanding the ecological and human patterns superimposed upon it...
eBook - ePubEcology
From Individuals to Ecosystems
- Michael Begon, Colin R. Townsend(Authors)
- 2020(Publication Date)
- Wiley(Publisher)
...Chapter 22 Ecology in a Changing World 22.1 Introduction Through the chapters of this book we have seen repeatedly that ecological systems are in a continual state of flux. At the small scale this may be driven by the dynamics of populations, with, for example, predator and prey affecting the densities of each other. Or externally driven disturbances may be responsible, such as the arrival of a new species (from local migration, or swept across seas or mountain tops by extreme weather events). Or ecosystems may change as a result of wildfire, drought, flood, hurricane or the impact of ungulate hooves in a patch of savanna. At a larger scale, ecosystems across the globe have been affected by gross climatic changes, such as the waxing and waning of ice ages, or periods of volcanic activity, or the impact of an asteroid. For most of the world's history, all these drivers of change were haphazard and natural. But then Homo sapiens arrived on the scene, dispersed and multiplied, moving through phases of agricultural, industrial, nuclear and technological revolution. Since 1950 our population has increased more than 2.5‐fold, and although the rate of increase is slowing, the world population is projected to increase to between 9.4 and 12.7 billion by 2100 (UN, 2019; and see Figure 5.20). While the haphazard factors are still operating in ecosystems, human actions have become the main driver of environmental change everywhere on the planet. the human epoch – the Anthropocene Indeed, since the turn of the millennium, support has been growing to recognise a new geological epoch that acknowledges our species' impacts. Once ratified by the International Commission on Stratigraphy (ICS), the ‘Anthropocene' will represent the section of geological history during which people have become a major geological (and, undoubtedly, ecological) force...
eBook - ePubLandscape Analysis
Investigating the potentials of space and place
- Per Stahlschmidt, Simon Swaffield, Jorgen Primdahl, Vibeke Nellemann(Authors)
- 2017(Publication Date)
- Routledge(Publisher)
...The biophysical character of landscapes is shaped by their geological, geomorphological and bio-geographical history and dynamics, and landscape change driven by natural factors tends to be episodic, with long periods of incremental evolution punctuated by major events such as drought and floods, landslips and earthquakes. Natural factors are the first driver for landscape change. Understanding the way that natural factors have shaped biophysical patterns and processes is crucial to all decisions on landscape, and biophysical surveys and analyses are therefore part of most landscape assessment. FIGURE 1.3 Driving forces of landscape change Framework illustrating how the Driving force starts the process: Pressure–State–Impact– Response (DPSIR). Source : Figure moderated from European Commission (2006). The second driver, technology change, may relate to: new systems and techniques of agricultural production (such as pasture management, irrigation systems or more efficient ploughs and tractors) new modes of transportation or changes in efficiency new modes of information technology changed sources of energy or industrial production changed habitation or leisure. New technologies tend to be introduced in waves, and particularly influence the scale and pattern of land-use practices. Analysis therefore needs to include understanding of the management systems affecting a landscape. Markets for finance, food, minerals, energy or land are a third driver of change, and market dynamics have profound consequences for landscapes. The European grain market opened for overseas imports in the 19th century, and was accompanied by technological innovations in transport (trains and cargo ships) and infrastructure (silos). The result was that agricultural landscapes changed dramatically all over Europe, but also changed around the world in colonies and countries which could now supply food to Europe...
eBook - ePubSustainable Landscape Management
Design, Construction, and Maintenance
- Ann Marie VanDerZanden, Thomas W. Cook(Authors)
- 2010(Publication Date)
- Wiley(Publisher)
...This multidisciplinary organization defines biodiversity as “the sum total of the variety of life and its interactions and can be subdivided into (1) genetic diversity, (2) species diversity, and (3) ecological or ecosystem diversity.” By taking into account the complex and interrelated features that constitute an ecosystem, ecological landscape design considers landscapes as ecosystems. This design approach addresses how to establish a new planting as well as what happens to the landscape over time as it matures and how environmental factors affect its growth, development, and function. This chapter will discuss the following: Sustainable landscapes and ecosystem services Historical review of ecological design How landscapes function as ecosystems Considerations in designing a new landscape ecosystem Establishment strategies for a new landscape ecosystem Management strategies for a landscape ecosystem THE CLIMAX STAGE OF AN ECOSYSTEM Ecosystems evolve over time by passing through a serial progression of phases. Ecologists originally believed that a climax phase was the end point of this progression and was a long-term steady state of the landscape. However, more recent research has shown that the climax phase is neither completely stable nor necessarily long term and self-perpetuating. Today, ecologists realize that the periodic disturbance of natural events such as fire, flooding, and damage by insects plays a critical role in maintaining the diversity of species and habitats in a region. These events are now considered essential to creating ecosystems in different succession stages, which include different vegetation types and result in different habitats...
eBook - ePub- Robert A. Francis, James D.A. Millington, George L.W. Perry, Emily S. Minor, Robert A. Francis, James D.A. Millington, George L.W. Perry, Emily S. Minor(Authors)
- 2021(Publication Date)
- Routledge(Publisher)
...Facing issues of sustainability, degradation, and fragmentation of (and the need to reconnect) natural and semi-natural ecosystems and landscapes required changing stakeholders’ views on landscape management, natural resource production, and environmental preservation (e.g. Van der Sluis et al., 2019). Consequently, the generalized development of landscape ecology in Europe has focused on the broad spatial arrangement and geography of discrete ecosystems and how these are structured and may change, interact, and ultimately be managed. An early example is the Kromme Rijn Project in The Netherlands (Tjallingii, 1974), wherein a 300 km 2 area of the river catchment (a tributary of the Rhine, or Rijn) was extensively mapped to delineate the spatial pattern of soils and vegetation in order to determine the diversity of such ecosystems and the potential impacts of development in the area. Interestingly, even in this early work, questions regarding the appropriateness of different ecological and biogeographical definitions (ecosystems, units, biocoenoses) arose; questions that still resonate today. This geographical work determined the importance of examining the natural world at broad spatial scales to understand not just how ecosystems are arranged but how abundant and diverse they are, and how equally broad-scale developments (e.g. road networks, land use change) may influence them. In North America, landscape ecology developed, rather, within a ‘systems science’ framework, or the examination of how a system may function (including characteristics and rates of biomass production, energy fluxes, nutrient cycles, maintenance of biodiversity, and so on) depending upon the spatial configuration of its components and the spatial scale under examination (Turner, 2005)...
