[...]... ability to maintain the baseline functions that define it Maintaining these baseline functions is, in fact, integral to an operational definition of ecosystem health In the words of Haskell et al (1992:9), “An ecological system is healthy if it is stable and sustainable—that is, if it is active and maintains its organization and autonomy over time and is resilient to stress.” Put another way, the basic... During times of open entrances the bones accumulated Then all entrances to the cave were apparently sealed between sometime in the Irvingtonian (based on the age of the youngest fossil bones) and the late 1800s, when miners opened an adit that intersected the Gypsum Room Since that time, bones have once again begun to accumulate in the cave from the processes described previously, but these are easy to. .. are due to all who lent a hand, and especially to the following individuals and institutions The kindness of Frank and Connie McMurry (McMurry Land and Livestock Company) in allowing us to excavate in their cave and spend field seasons at their cow camp made the whole project possible I am deeply indebted to them The project would also not have been possible without financial support from the U.S National... 3.3 Looking southwest across the northern portion of South Park toward the Mosquito Range 29 5.1 Geological sketch of the vicinity of Porcupine Cave 52 3.4 Winter view looking west to Silverheels Mountain just north of Fairplay 29 5.2 Cross section showing inclined strata and Porcupine Cave 53 xv 5.3 Stratigraphic section at Porcupine Cave 53 9.9 5.4 Panel diagram of the ridge containing Porcupine Cave... International Union of Quaternary Research Subcommission 1d at the 27th International Geological Congress in Moscow in 1984 (Bell et al., in press), and subsequent correlation of the boundary with the magnetostratigraphic and radiometric time scales (Cande and Kent, 1995; Berggren et al., 1995) The use of the term middle Pleistocene in this book is informal and refers to the middle third of the Pleistocene, ... glacial-interglacial cycles, from a 41,000-year rhythm in the early Pleistocene to a 100,000-year rhythm that was firmly in place by 600,000 years ago Therefore it is possible to track a single ecosystem through climate changes of variable intensity and to assess the biodiversity response, which is one goal of this book However, an equally important goal has been to make the data available to future... dynamics and how the fossil information applies to understanding the effects of climatic warming on biodiversity The nature of the data makes it possible to examine how climate change affected biodiversity in terms of trophic and size structure, species richness, species composition, and population change An overriding impetus for this effort has been the need to establish a baseline that will allow... How then do rates of climate change scale with the interval of time over which the climate change is measured? Figure 1.1 answers this question The data were compiled from paleotemperature proxies provided mainly by oxygen isotope curves (Barnosky et al., 2003) The shorter the interval of time over which the temperature is measured, the faster the per-hundred-year rate of change appears Plotting these... following chapters are probably among the most pronounced that might be expected in naturally varying systems Therefore they may be useful as an ecological baseline against which future changes can be measured As global warming continues into the coming decades, changes in biodiversity and other faunal dynamics will undoubtedly occur—indeed are probably already occurring (Schneider and Root, 1998; Post... with the publication of a compendium of papers, edited by Peters and Lovejoy (1992), concerning the effects of global warming on biodiversity The effects of climate change on biodiversity are a matter of concern because biodiversity is often associated with ecosystem health Significant losses in biodiversity may be analogous to the death of the canary in the coal mine, which signals that the mine is . h0" alt="" Biodiversity Response to Climate Change in the Middle Pleistocene The publisher gratefully acknowledges the generous contribution to this book. provided by the General Endowment Fund of the University of California Press Associates. Biodiversity Response to Climate Change in the Middle Pleistocene The