Advancing the Science of Climate Change (2010) / Chapter Skim
Currently Skimming:
9 Ecosystems, Ecosystem Services, and Biodiversity
9 Ecosystems, Ecosystem Services, and Biodiversity
Pages 271-290
The Chapter Skim interface presents what we've algorithmically identified as the most significant single chunk of text within every page in the chapter.
Select key terms on the right to highlight them within pages of the chapter.
From page 271... ...
Climate change has already led to a number of changes in both terrestrial and marine ecosystems, and future climate change will strongly influence biodiversity, ecosystem processes, and ecosystem services, adding to other stresses on ecosystems from human activities. Some questions decision makers are asking, or will be asking, about ecosystems management in the context of climate change include the following: • How is climate change -- including changes in temperature, precipitation, and the chemistry of the atmosphere and oceans -- altering the distribution of species?
|
From page 272... ...
, including the effects of ocean acidification, and also briefly summarizes current scientific knowledge about the potential role of ecosystems in limiting the magnitude of climate change and possible strategies for helping ecosystems adapt to climate change and other environmental stresses. The last section of the chapter outlines key research needs in all of these areas.
|
From page 273... ...
. Box 9.1.pdf bitmap TERRESTRIAL ECOSYSTEMS Impacts of Climate Change on Land-Based Ecosystems and Biodiversity A series of place-based observations, meta-analyses, and models indicate that climate shifts have already begun to change the geographical range of plants and animal species on land (IPRC, 2007c)
|
From page 274... ...
. Recent research indicates that earlier snowmelt, temperature changes, and drought associated with climate change are important contributors to this increase in forest fire (Westerling et al., 2006)
|
From page 275... ...
. Considering indirect impacts, such as ocean acidification, ground-level air pollution, and climate change, virtually all ecosystems on Earth are being affected in some way by climate change, and other human pressures on ecosystems are also growing significantly (Auffhammer et al., 2006; Chameides et al., 1994; Orr et al., 2005)
|
From page 276... ...
and oak-pine (light green) forest types expand landscape their ranges.
|
From page 277... ...
In addition, very little is known yet about the social acceptability of new and evolving approaches to species conservation and land protection (including the Endangered Species Act under significant climate change, when many more species are at risk of extinction) or the social acceptability of a triage approach to species protection that may evolve as ecosystem functions are affected by climatic and species changes.
|
From page 278... ...
Deforestation, arid land degradation, and the transformation of ecosystems into builtup areas, for example, tend to increase reflectivity of the land surface and decrease evapotranspiration, leading to both local climate changes and, in combination with other land use changes, influencing large-scale climate forcing, feedbacks, and atmo
|
From page 279... ...
. Accurate biomass estimates are critical for improving estimates of GHG emissions generated by deforestation (Houghton, 2005)
|
From page 280... ...
In forest ecosystems, protection from fire, insect damage, and forest thinning through logging and other human use can enhance carbon storage as can secondary regrowth of forests in abandoned croplands, tree plantations, and agroforestry (Rhemtulla et al., 2009; Gough et al., 2008)
|
From page 281... ...
Given the prominent role of oceans in storing carbon, climate impacts on ocean productivity could also alter their role in the carbon cycle. Overall, oceans contribute roughly half of the globe's net primary productivity (NPP; Field et al., 1998)
|
From page 282... ...
These changes alter both the food webs of animals that ultimately depend on these different sources of productivity, including humans (Grebmeier et al., 2006; Mueter and Litzow, 2008; USGCRP, 2009a) , and the role of high-latitude ocean ecosystems in the carbon cycle.
|
From page 283... ...
. Strong upwelling of deep cold waters can pull such hypoxic water onto shallow ocean shelves with devastating impacts on many marine species (Grantham et al., 2004)
|
From page 284... ...
. The next subsection discusses ocean acidification, which serves as an additional and potentially devastating stressor to corals.
|
From page 285... ...
. bitmap Ocean Acidification In addition to its climate impacts, CO2 released by human activities can influence ecosystem dynamics in aquatic systems by altering water chemistry -- in particular, the reaction of CO2 with water to form carbonic acid (H2CO3)
|
From page 286... ...
. A broad array of marine species produce CaCO3 skeletons during at least part of their life cycle, so ocean acidification threatens nearly all ocean ecosystems by altering calcification rates while simultaneously increasing the rate of CaCO3 dissolution (Yates and Halley, 2006)
|
From page 287... ...
Because the oceans provide such an enormous reservoir for carbon storage, it may be possible to manipulate (i.e., geoengineer -- see Chapter 15) ocean ecosystems to cause a transfer of CO2 from the atmosphere to the oceans.
|
From page 288... ...
While maximum storage rates are projected to be at most a few percent of total human-generated GHG emissions, significant questions remain regarding exactly how much carbon could be stored, and for how long, using these approaches. Furthermore, considerations such as ocean acidification and the difficulty of predicting responses of marine ecosystems make it doubtful whether such manipulations could contribute to overall environmental risk reduction.
|
From page 289... ...
Although MPAs can be dramatically successful at restoring depleted ocean ecosystems (Lester et al., 2009) , many questions remain: • Will the effectiveness of MPAs be compromised by climate change, ocean acidification and/or the migration of marine species outside the boundaries of protected areas?
|
From page 290... ...
There is a great need for global-scale, longterm, and continuous observations of land and ocean ecosystems and ongoing changes within them. Such observations will enable measures of ecological processes at relatively fine spatial and temporal scales, which are needed both to provide critical inputs to Earth system models and to track gradual and abrupt change in Earth system processes.
|
Key Terms
This material may be derived from roughly machine-read images, and so is provided only to facilitate research.
More
information on Chapter Skim is available.