Chapter 05

Author: Lee Hannah

FIGURE 5.1 Tropical Forest Test Bed.Barro Colorado Island has been described as the premier test bed for tropical ecology. The forest canopy at BCI (right) often shows synchronous fl owering in one or more species. A satellite photo (left) shows how rising lake waters during construction of the Panama Canal isolated the island. Left Photo: NASA; Right Photo: Christian Ziegler, Wikimedia Commons.

FIGURE 5.2 Drought in the Amazon, 2005.The Amazon was affected by a major drought in 2005. Rainfall defi cit (right) indicates the areas most severely affected. Primary productivity (left) increased despite the drought in many areas. The mechanism for this unexpected result is the subject of continuing research. Source: Kamel Didan, University of Arizona Terrestrial Biophysics and Remote Sensing Lab.

FIGURE 5.3 Cloud Forest, Monteverde, Costa Rica.Photo: John J. Messo, NBII, USGS.

FIGURE 5.4 Monteverde Population Fluctuations Synched to Dry Days.Twenty species of frogs and toads disappeared from the Monteverde cloud forest in Costa Rica (fi rstblack bar) after an unusually long run of dry days (solid line). The golden toad ( Bufo periglenes ) waslocally endemic, so its disappearance represented a global extinction, perhaps the fi rst extinction linked to climate change. Subsequent long dry spells have caused other frog population crashes since 1987 (inset). Increasing frequency of dry spells in cloud forest is linked to climate change through the lifting cloud base effect. Dry periods appear to favor pathogenic growth of the fungus that is the ultimate cause of death in affected frogs. Reproduced with permission from Nature .

FIGURE 5.5 Bark Beetle Outbreaks in British Columbia.Bark beetle outbreaks spread rapidly through British Columbia in the 1990s and early 2000s. In 2001, peak increase in outbreak area occurred. Copyright Her Majesty the Queen in Right of Canada, Canadian Forest Service, as originally published in Nature .

FIGURE 5.6 Bark Beetle-Killed Trees and Bark Beetle Damage in Tree Limb. (a) Copyright University Corporation for Atmospheric Research. Photo by Carlye Calvin. (b) Deborah Bell, Smithsonian National Museum of Natural History.

FIGURE 5.7 Dead Stands of Lodgepole Pine in British Columbia. Reproduced with permission from the Ecological Society of America.

FIGURE 5.8 Map of Current and Potential Beetle Habitat, Lodgepole and Jack Pine.Eastern jack pine forests have been isolated from bark beetle habitat by the continental divide and grasslands of the Midwest. Extension of beetle habitat upslope with warming is crossing the continental divide and skirting grasslands through the continuous forests to the north in Canada. Reproduced with permission from the Ecological Society of America.

FIGURE 5.10 Loss of Tropical Glaciers.Photos of Puncak Jaya glacier in Papua New Guinea from 1936 (a) and 1972 (b). Tropical vegetation is moving into areas formerly covered by the ice of this glacier. From Wikimedia Commons.

FIGURE 5.11 Qori Kalis Glacier, Peru.The Qori Kalis glacier is the most signifi cant ice outlet from the Quelccaya ice cap on the Cordillera Vilcanota in southeast Peru. Its extent in 1978 (a) was much larger than in 2004 (b). In only 5 years, this glacier has retreated more than half a kilometer. New ecosystems are developing in the freshwater ponds left behind by the glacier. Photos courtesy Lonnie Thompson, Ohio State University.

FIGURE 5.12 Sockeye salmon ( Oncorhynchus nerka ) is an anadromous species sensitive to climate change in both its freshwater and its marine life stages. From Wikimedia Commons.

FIGURE 5.13 Map of Ponderosa Retreat in Sierras.Ponderosa pine range has been reduced in the Sierra Nevada mountains of California since 1930. Upslope movement of montane hardwoods (dominated by Quercus sp.) has been replacing the lower range margin of ponderosa pine (left) while temperature has been increasing in the region (right ). Upslope loss in ponderosa pine is detected by comparing vegetation surveys from the 1930s (Wieslander VTM survey) to modern vegetation maps. The area of retreat in freezeline (yellow, right) closely corresponds to the area of pine loss (red-purple, left). Figure courtesy of Jim Thorne.

FIGURE 5.14 Polar Bear and Cubs in Ice Den. From Wikimedia Commons.

FIGURE 5.15 Retreating Arctic Sea Ice.As sea ice extent decreases in the Arctic, ice retreats away from the continental shelf, requiring polar bears to return to land earlier in the year and diving species such as walrus and eider to dive deeper to obtain food. Images courtesy of the National Snow and Ice Data Center, University of Colorado, Boulder.

FIGURE 5.16 Pack Ice Changes and Declining Penguin Populations in the Antarctic. Sea ice changes in the Antarctic are less straightforward than the continual declines in the Arctic. In some areas Antarctic pack ice is lasting longer, while in other places it is declining in duration. Associated withthese changes, are changes in penguin populations driven by changes in food availability as plankton habitat is altered by the changes in sea ice. Decreases in pack ice duration are being driven by warming, while increases in pack ice duration are being driven by changes in winds (which may also be driven byclimate change). Source: Atkinson et al., 2004.

FIGURE 5.17 Example of an Antarctic Food Web.Diatoms dependent on sea ice support a diverse food web, including great whales that feed directly on plankton and several food chains that have diatoms at their base.

FIGURE 5.18 Coral Reef Fish Catch in Papua New Guinea.Catches of coral-associated fi sh may decline following reef bleachingepisodes.

FIGURE 5.19 Variation in Fisheries Correlated with Climate Indices.ACI is Atmospheric Circulation Index. Reproduced with permission from the Food and Agricultural Organisation of United Nations.

FIGURE 5.20 Horse Mackerel ( Trachurus trachurus ) Food Chain.Reproduced with the permission of Her Majesty the Queen in Right of Canada, 2010.

FIGURE 5.21 A regime shift in the Gulf of Maine and Georges Bank occurred in 1990 in response to climate change. Salinity dropped, resulting in increases in phytoplankton and zooplankton (copepod) abundance. The cause of the salinity change was large-scale reorganization of ocean circulation in the Arctic (map). In the late 1980s, warm saline Atlantic water entered the Barents Sea. This reduced the size of the Beaufort Gyre and caused increased flow of low-salinity water out the Canadian archipelago west of Greenland. When this water reached Georges Bank (around 1990), it triggered the ecological regime shift in plankton (left panels). Reproduced with permission from AAAS.

FIGURE 5.22 External Appearance and Crystalline Form of Calcite (a and b) and Aragonite (c and d). (a) and (c) from Wikimedia Commons. (b) and (d) from http://staff.aist.go.jp/nomura-k/english/itscgallary-e.htm.

FIGURE 5.23 Thawing Permafrost Soils. As permafrost thaws, it expands, rupturing the surface. This can cause damage to vegetation or structures, opens up new habitat, and impacts nutrient cycling. (a) and (c) Courtesy of NASA/GSFC/MITI/ERSDAC/JAROS and the U.S./Japan ASTER Science Team. (b) From Wikimedia Commons.

FIGURE 5.24 Moisture Recycling in Amazon.Moisture transpired by trees in the Amazon basin enters the atmosphere, contributing to cloud formation. Prevailing winds carry this moisture toward the west, where it re-enters forest as precipitation and is transpired again. This process continues until air masses are blocked by the vertical rise of the Andes. This transpiration and precipitation cycle is important in maintaining forest cover in the Amazon in times of climate change.Adapted from http://www.greenhealth.org.uk/Images/Transpiration%20Cycle.JPG.

FIGURE 5.25 Tropical cloud forests form where clouds intersect mountain slopes (top).Under climate change or lowland land clearing, lowered relative humidity at altitude means clouds will form higher (bottom), reducing the area of intersection with mountains and decreasing the extent of cloud forest, possibly causing loss of some of the many endemic species found there. In this schematic, increasing relative humidity and cloud condensation are indicated by shades of orange. Source: Lawton et al., 2001.

Un - Figure 5.1 Walrus and spectacled eider rest on sea ice and dive deep to feed on bottom fauna (left). With warming, sea ice melts, and both speciesspend more time in water and have to dive deeper (right).