in high elevation forests in pennsylvania weegy. Elevation and topographic posi tion have been recognized as key factors affect ing the distribution of these forest communitiesCarbon stock in 12 major forest types along an elevational gradient (350–3450 masl) in the Indian Himalaya quantified. in high elevation forests in pennsylvania weegy

 
 Elevation and topographic posi tion have been recognized as key factors affect ing the distribution of these forest communitiesCarbon stock in 12 major forest types along an elevational gradient (350–3450 masl) in the Indian Himalaya quantifiedin high elevation forests in pennsylvania weegy  political regions C

tropical forest D. We found that the amount of burning in subalpine forests of the Northern Rockies over the 20th and 21st. Proceedings from the conference on the ecology and management of high-elevation forests in the central and southern Appalachian Mountains. We have affected the squir-rels’ habitat in several ways. (Fig. g. The San Francisco Peaks/Dook’o’oosłííd in northern Arizona rise to 3851 m elevation with slopes that span many of the major forest types of the southwestern US mountains. What's this phenomenon? Advertisement Expert-Verified Answer question 1 person found it helpful pstnonsonjoku Weegy: In high-elevation forests in Pennsylvania, ecologists have noticed a serious decline in certain tree species. User: Because they are located above 15,000 feet, areas in the Tierra Nevada elevation zone have _____ ecosystems. mitchellii is only known from high-elevation Polylepis forests of Peru, whereas D. Proceedings from the Conference on the Ecology and Management of High-Elevation Forests in the Central and Southern Appalachian Mountains 94 GTR-NRS-P-64 INTRODUCTION Habitat fragmentation is a major factor in the loss of forest biodiversity (Hagan et al. Some scientists propose that increased soil acidity might be the cause. These changing conditions have significant implications for carbon storage, snowpack, and the. A. In high elevation forest in Pennsylvania ecologists have noticed a serious decline in certain tree species. High-elevation forests only burn about once every 100 to 250 or more years on average. Fine root nutrient dynamics were calculated for one year in three high elevation forests of Indian central. Balsam fir dominates, although heartleaf birch and red spruce may be present. The phenomenon is: Acid rain, which is caused by SO2 from combustion mixed with atmospheric water vapor. The northern hardwood forest occupies the northern third of the state and extends south at high elevations along the Allegheny Front. Some scientists propose that increased soil acidity might. l. economic regions The forests of the Pacific Northwest are just one of the many different economic regions in the United States where many people work in the same industry. User: which states passed laws outlawing slavery after the war Weegy: Pennsylvania, New Hampshire, Massachusetts, Connecticut and Rhode Island passed laws outlawing slavery after the war. Because these areas are determined by natural terrain, ecology, and conservation priorities, many ecoregions do not adhere to state boundaries, and the High Allegheny Plateau. This phenomenon is: Decreased in pH caused by climate change. A contour interval is the difference in elevation between any two adjacent contour lines. 9 m/y. Turkey Path Trail, Leonard Harrison State Park. This page shows the elevation/altitude information of Pennsylvania, USA, including elevation map, topographic map, narometric pressure, longitude and latitude. Rating. Soils are wetter than in the other two high-elevation forest communities and the vegetation of the community resembles that of lowland spruce - fir forest. The main aim is to relate differences within and between the forests to current theory on the effect of human disturbance on primate. Forests in Pennsylvania provide landowners with a multitude of benefits that range from providing high-quality wildlife habitat to producing valuable timber. This resulted in 40 106 out of the 159 sites being selected. Ask a question. Expert Answered. Polylepis (Rosaceae: Sanguisorbeae) forests are distributed across the Central Andes between elevations of 3500 to 5200 m a. The Appalachian–Blue Ridge forests are an ecoregion in the Temperate broadleaf and mixed forests Biome, in the Eastern United States. Decreased in pH caused by climate change C. ) and subalpine forests dominate the upper montane ecosystems of the Sierra Nevada. In high-elevation forests in Pennsylvania, ecologists have noticed a serious decline in certain tree species. s. climate regions D. Some scientists propose that increased soil acidity might be the cause. A. Whitebark pine and Englemann spruce are present in drier sites on the east side of the park. In high-elevation forests in Pennsylvania, ecologists have noticed a serious decline in certain tree species. Davis. Location: North Central Pennsylvania in Tiadaghton State Forest near the settlement of Slate Run. Here, a four-year litterbag decomposition experiment along an elevation gradient (3000, 3300, 3600 m) was conducted in an Abies faxoniana Rehd. Black Forest Trail Quick Facts. highland C. (2016. The upper limit of montane forests, the tree line, is often marked by a change to es that. (18°56′S and 69°00′W). Some scientists propose that increased soil acidity might be the cause. These are high-altitude valleys in the Himalaya, characterized by upper temperate and subalpine climatic conditions. grassland B. Ask a question. tarapacana comprising an elevation range from 4337 to 4905 m a. What's this phenomenon ? A. , 2012). In high elevation forest in Pennsylvania ecologists have noticed a serious decline in certain tree species. We document an upslope advancement of high-elevation fires of 7. The phenomenon is: Acid rain, which is caused by SO2 from combustion mixed with atmospheric water vapor. The phenomenon is: Acid rain, which is caused by SO2 from combustion mixed with atmospheric water vapor. 08/26/2020 Biology College answered • expert verified In high-elevation forests in Pennsylvania, ecologists have noticed a serious decline in certain tree species. 10 °C for. High-altitude forests cover 16 million hectares (40 million acres) of land in Africa, primarily concentrated in the Democratic Republic of Congo, but about 5% has already disappeared since the. Question. Their highest peak, with an elevation of 4,223 feet (1,287 m) above mean. In high-elevation forests in Pennsylvania, ecologists have noticed a serious decline in certain tree species. Ourmodel containing Elevation + TEI, the latitude variable, and all interactions between the variables was shown to be the best approximating model for the overall study area (Table 2). Length 0. crossleyi is also found at low, middle, and high altitude forests, from northern to southern Madagascar, including sites along the eastern edge of the central plateau (Blanco et al. The National Audubon Society reports that deforestation has led to over a fifty percent decline in their population levels over the past forty years. Climate will increasingly determine post-fire tree regeneration success in low-elevation forests, Northern Rockies, USA. chaparralfir-hemlock, these high-elevation forests contain substantial amounts of Douglas-fir, both as stands and as scattered trees or groups intermingled with other species. Whats the phenomenon? A. long-term atmospheric circulation. BEST HIKES ON THE BLUE RIDGE PARKWAY IN NC. 9787 10/21/2020 Biology College answer answered in high elevation forests n Pennsylvania, ecologists have noticed a serious decline in certain tree species. Elevation range of reserve varies from 1800 to 7817 m. cannot support long-term agricultural production. Book County High Points by Andy Martin; list compiled 1993 by Andy Martin, reviewed by Michael Schwartz. The phenomenon is: Acid rain, which is caused by SO2 from combustion mixed with atmospheric water vapor. Some scientists propose that increased soil acidity might be the cause. Pennsylvania County High Points. The phenomenon is: Acid rain, which is caused by SO2 from combustion mixed with atmospheric water vapor. Colonies aggregate at nesting sites called roosts. Study with Quizlet and memorize flashcards containing terms like Which is one way that topographic maps are different from other maps?, A new mall will be constructed in a large city. moist summers and dry winters b. It covers an area of about 61,500 square miles (159,000 km 2) in:. Some scientists propose that increased soil acidity might be the cause. At high altitude the air composition is characterized by low contents of fine particles (dust, etc. Together, these factors control the range of temperatures and the amount of rain and/or snow each region receives. 3. grassland B. Some scientists propose that increased soil acidity might be the. Forests in the mountains are mostly dominated by Pacific silver fir and mountain or western hemlock. 3. Some scientists propose that increased soil acidity might be the cause. grassland B. , 2018; Silva, 2017). 50 °C ± 0. We document an upslope advancement of high-elevation fires of 7. Northeast. , the mid-altitude forest (MF), ranging from 1700 m a. 2023; Attempts at identifying climate warming effects on. chaparralPennsylvania boreal conifer forests and their bird communities: past, present, and potential. 1 The treeline concept. These high-elevation forests share several charac-teristics, including high snowpack retention, low species diversity, low evapotrans-piration and climatic water deficit, longer and more variable fire return intervals, and high sensitivity to changes in climate. )- and eastern hemlock (Tsuga canadensis)-dominated forests, found primarily on glaciated parts of the Allegheny Plateau, are relicts of boreal forest that covered the region following glacial retreat. The. Relief shows the difference in elevation between two points on a map. In high-elevation forests in. Most high-elevation forests haven’t been subjected to much fire suppression, logging or other human activities, and because trees at these high elevations are in wetter forests, they historically have long return intervals between fires, typically a century or more. Get an answer. In high-elevation forests in Pennsylvania, ecologists have noticed a serious decline in certain tree species. In high elevation forest in Pennsylvania ecologists have noticed a serious decline in certain tree species. highland C. Easy • 4. Print/PDF map. In high-elevation forests in Pennsylvania, ecologists have noticed a serious. In high-elevation forests in Pennsylvania, ecologists have noticed a serious decline in certain tree species. User: how. Similar to our study, Sharma et al. We predicted mountain lions select hiding cover in the form of high canopy forests, forested drainage bottoms, and rugged terrain that can facilitate stalking prey, and that they avoid open vegetation cover. Weegy: In high-elevation forests in Pennsylvania, ecologists have noticed a serious decline in certain tree species. Pine Creek Gorge, located in Tioga State Forest, is known as the Grand Canyon of Pennsylvania for its dramatic views and steep glacially carved walls. 2010. Updated at : December 11, 2020 23:29. Some maps are so common that a child would recognize them, while others are used only by professionals in specialized fields. This phenomenon is: Decreased in pH caused by climate change. 50 °C ± 0. Here, we assessed soil properties beneath adjacent stands of trembling aspen, lodgepole pine, and Engelmann spruce, which are dominant tree. This phenomenon is: Decreased in pH caused by climate change. Some scientists propose that increased soil. Trees and the insects that eat them wage constant war. Mount Davis is the highest point in Pennsylvania. Pennsylvania Department of Conservation and Natural Resources plans to add 6 forests to Old-Growth Network this year. 6 km 2). Alaska. fir-hemlock, these high-elevation forests contain substantial amounts of Douglas-fir, both as stands and as scattered trees or groups intermingled with other species. High elevation and the rain-shadow effect from theThe record-setting 2020 fire season, with three of Colorado’s largest fires, helped push the rate of burning in high-elevation forests in Colorado and Wyoming into uncharted territory relative. soils with high mineral content d. D. Acid caused by S*O_{3} combustion mixed with atmospheric water vapor B. If climate warming continues in northeastern China, further continuous and substantial increase in tree growth would substantially raise forest productivity in mixed coniferous and broad-leaved forests. 2005). In high elevation forest in Pennsylvania ecologists have noticed a serious decline in certain tree species. In high elevation forests in the Southern Rocky Mountains, North America, areas that are dominated by a single tree species are often adjacent to areas dominated by another tree species. highland C. New research shows high-elevation forests in the Rocky Mountains are burning more now than any time in the past 2,000 years amid extreme, climate change-induced drought. In high-elevation forests in Pennsylvania, ecologists have noticed a serious decline in certain tree species. Search for an answer or ask Weegy. 7 km 2) and birch (340. Study site and elevation gradient. Lowland forests are dominated by western hemlock, Douglas-fir, and western redcedar. In high elevation forest in Pennsylvania ecologists have noticed a serious decline in certain tree species. Andrew Holguin, Andrew Holguin. Pennsylvania, constituent state of the U. View. Species niche differences shape our high-elevation forest communities. [Google Scholar] KullmanL. In recent decades, due to constant anthropogenic pressure and considerable changes witnessed in the climate of the region, species of this region are threatened. Glaciation and European settlement have created a more patchy forest in the state with fewer old forests. When density altitude is higher than indicated altitude. A. com is the easiest and fastest way to get answers to your questions, by providing a mashup of several technologies including an AI-enabled Q&A knowledgebase and integrated chat with live experts. Choose the factors that influence the climate of the U. political regions C. gov website. Some scientists propose that increased soil acidity might be the cause. It is the. Some scientists propose that increased soil acidity might be the cause. 3. P. chaparralPine Creek Gorge- “Pennsylvania Grand Canyon”. To reconstruct past fire regimes across this broad. Some scientists propose that increased soil acidity might be the cause. In high elevation forest in Pennsylvania ecologists have noticed a serious decline in certain tree species. The identification and evaluation of forest biophysical parameters are very crucial in the current era of climate change. In high elevation forest in Pennsylvania ecologists have noticed a serious decline in certain tree species. New answers. In previous studies of tropical endophytes, Leotiomycetes have been considered rare 25,31, yet we detected them relatively frequently in the oak-dominated, high-elevation forests that share major. Acid caused by S*O_{3} combustion mixed with atmospheric water vapor B. 7 km 2) and birch (340. Weegy: In high-elevation forests in Pennsylvania, ecologists have noticed a serious decline in certain tree species. Vargas‐Hernández1, J. Score 1 User: The ring of fire on the map. Rose Wilderness Area outside of Reno, Nevada, USA. Based on above finding, it is concluded that overall magnitude of anthropogenic pressure was significant in the area. In high-elevation forests in Pennsylvania, ecologists have noticed a serious decline in certain tree species. High elevations in the Olympic Mountains have subalpine parkland and alpine. 2004). In high-elevation forests in Pennsylvania, ecologists have noticed a serious decline in certain tree species. Some scientists propose that increased soil acidity might be the cause. Rating. Some scientists propose that increased acidity might be the cause this phenomenon? weegy. Rentch, James S. High-elevation forests including treeline ecotones are particularly valuable as wildlife habitats and because of their protective function such as avalanche and erosion control (e. In this study, we assessed patterns of structure and tree species. In addition, CSU-MC has a challenge course (ropes, climbing, team-building) that are an optional element for Phys-Fest participants. political regions C. Elevation + TEI indicated that the predicted occurrence of the northern hardwood forest type was negatively correlated with elevation and TEI when. Following 2020's extreme fire season, high-elevation forests in the central Rocky Mountains now are burning more than at any point in the past 2,000 years, according to a new. These forests are at elevations ranging between 5,000 and 10,000 feet, says Smithsonian. Some scientists propose that increased soil acidity might be the cause. 3. Forest Glow - in explore. The trail winds and weaves through a lush forest dense with rhododendron, hemlock, and fir, and climbs to 180-degree views of Chimney Tops and nearby Mt LeConte. High altitude tree growth is predominantly limited by low temperature, and thus more responsive to climate warming. High-elevation forest stands across the mountain range are reminiscent of the high-latitude boreal-deciduous ecotone (Whittaker, 1956), and include a northern hardwood species assemblage with isolated spruce-fir forest zones. periodic fires, The biome with high amounts of precipitation, large narrow. Most high-elevation forests haven’t been subjected to much fire suppression, logging or other human activities, and because trees at these high elevations are in wetter forests, they historically have long return intervals between fires, typically a century or more. The mountain pine beetle (MPB) is one of the most significant disturbance agents shaping pine forests, and like all insects, temperature is a major driver of its population success and. Weegy: Tobacco was the most valuable cash crop produced in the 1700s until the invention of the cotton gin; happened to tobacco in the mid 1700s. Search for an answer or ask Weegy. In high-elevation forests in Pennsylvania, ecologists have noticed a serious decline in certain tree species. For almost a hundred years, the U. Mercury contamination B. As climate warms, bark beetles march on high-elevation forests. Old growth forests are present in small, remnant pockets in Pennsylvania. A. Search for an answer or ask Weegy. political regions C. The study, published today in the journal Nature Communications, found that white pine blister rust disease expanded its range into higher-elevation forests in the southern Sierra Nevada between. elevation regions B. The primary objectives of this study were to (1) measure N input, uptake, internal generation and export; (2) quantify N pools in biomass and soils in a high-elevation forest in the Adirondacks of New York; and (3) assess the relative importance of atmospheric deposition of N compounds in N cycling. in high elevation forests n Pennsylvania, ecologists have noticed a serious decline in certain tree species. A habitat that has lots of light and water, a high elevation, low temperatures, and a low level of oxygen is most likely a high mountain. Crawford: Czeck Benchmark:. Some scientists propose that increased soil acidity might be the cause. They were joined by the charcoal industry; an ironworks furnace cleared roughly an acre of trees every day to make charcoal, a key. yr(-1)). Proceedings from the Conference on the Ecology and Management of High-Elevation Forests in the Central and Southern Appalachian Mountains GTR-NRS-P-64 95 (Fenneman 1938). The vertical differentiation of climatic conditions and the strong altitudinal gradients result in a characteristic vegetational zonation (Ozenda and Borel, 1990) with. Some scientists propose that increased soil acidity might be the cause. In: Goldammer JG, Jenkins MJ (eds) Fire in Ecosystem Dynamics, The Hague, pp 191–199It is now evident that many high elevation five-needle pine (HEFNP) forests in western North America are declining because of complex interactions across multiple disturbance factors (Keane et al. Some scientists propose that increased soil acidity might be the cause. 1400 meters), high elevation forests are characterized by subalpine fir, mountain hemlock, and Alaskan yellow cedar. In high-elevation forests in Pennsylvania, ecologists have noticed a serious decline in certain tree species. In high-elevation forests in Pennsylvania, ecologists have noticed a serious decline in certain tree species. Mercury. Whereas it does not occur in the dry forests of the. Weegy: In high-elevation forests in Pennsylvania, ecologists have noticed a serious decline in certain tree species. Tech. B) Denver. Some scientists propose that increased soil acidity might be the cause. Denali is the highest point in the United States and is located in the Alaska Range in the interior of the U. The phenomenon is: Acid rain, which is caused by SO2 from combustion mixed with atmospheric water vapor. This phenomenon is: Decreased in pH caused by climate change. Strong interannual links between aridity and high. Comparatively, the forest growth at low elevation sites has increased faster than that at high elevation sites. This study was carried out in two high-elevation forest sites in the Chilean Altiplano, one of P. Virginians for Wilderness Web Site. lower than the actual altitude above sea level. Some scientists propose that increased soil acidity might be the cause. Some scientists propose that increased soil acidity might be the cause. Proceedings from the conference on the ecology and management of high-elevation forests in the central and southern Appalachian Mountains. N concentration in fine roots was highest followed by K and P. This process is. S. From the preceding analysis, it is evident that the average elevation of treeline in the Western Himalaya is around 3615 m asl, but trees are recorded up to 4200 m. C. Latitude, temperature, moisture and elevation define the distribution of various temperate forests and trees. , the Qinghai spruce forests are also mainly distributed at the middle- and lower-slopes, accounting for 34. Pennsylvania Natural Heritage Program information for the conservation of biodiversity WILD HERITAGE NEWS Summer 2022 Most people picture massive, towering trees when they think of an old growth forest, and they usually aren’t thinking of Pennsylvania. Connotative Weegy: Connotative definitions are. elevation regions B. Logging and subsequent fires during the early part of this century changed large areas of high elevation forests in the Great Balsam and Black Mountains. — could be at risk this year and in future wildfire seasons. 1). Furthermore, warming has changed characteristics of wildfires enabling a median upslope advance of 252 m in high. In high-elevation forests in Pennsylvania, ecologists have noticed a serious decline in certain tree species. 3. In high elevation forest in Pennsylvania ecologists have noticed a serious decline in certain tree species. RHOADES, 1,3 ROBERT M. highland C. Forest: Forest County High Point: 1954: Northern Allegheny Plateau: 134: 14: 42. Most Pennsylvania forests are now in age classes between 60 and 120 years, with the largest 10-year classes in the 81- to 100-year range (Jenkins et al. 9 m/y. tropical forest D. climate regions D. Ponderosa pine (Pinus ponderosa), also called western yellow pine, is one of the most widely distributed pines in western North America. km. rugulosa at 3777 m a. Some scientists propose that increased soil acidity might be the cause. grassland B. 6% of the total area of. Book County High Points by Andy Martin; list compiled 1993 by Andy Martin, reviewed by Michael Schwartz. grassland B. Forest trees exhibit a large variation in basal area increment, which depends on tree specific factors, inter-tree relations and the environment. Little information exists specific to the response to disturbance, including timber harvesting, in. In high elevation forest in Pennsylvania ecologists have noticed a serious decline in certain tree species. gov website. This milestone for the country covers an official area of 386,176 acres (just over 1,500 square kilometers) of remote, high-altitude forest. The highest amounts of nutrients in both live and dead fine roots were observed in September and the lowest in the month of June and turnover rates of the nutrients in the fine roots also decreased with an increase in elevation. Glaciation and European settlement have created a more patchy forest in the state with fewer old forests. , 2005; D’Arrigo et al. Some scientists propose that increased soil acidity might. chaparralSearch for an answer or ask Weegy. and high elevation spruce-fir forests of the south western United States have focused on classifi cation and silviculture (e. Tree growth in high-elevation forests may increase as a result of increasing temperatures and CO2 concentrations in the atmosphere (Ca). , Alexander 1974; Dye & Moir 1977; Layser & Schubert 1979; Moir & Ludwig 1979). The Hindu Kush Himalaya (HKH) has experienced the most rapid climate warming in. chaparral Weegy: Because they are located above 15,000 feet, areas in the Tierra Nevada elevation zone have highland ecosystems. grassland B. The tallest redwood in the world is called Hyperion, standing at an incredible 380 feet. Following 2020's extreme fire season, high-elevation forests in the central Rocky Mountains now are burning more than at any point in the past 2,000 years, according to a new study. Correa‐Díaz 1, L. Wildfires in California’s fabled Sierra Nevada mountain range are increasingly burning high-elevation forests, which historically have seldom burned, reports a team of researchers led by the John Muir Institute of the Environment at the University of California, Davis. climate regions D. (Kessler and Schmidt-Lebuhn, 2006). , 2019). Worlds End State Park is a 780-acre (316 ha) Pennsylvania state park in Sullivan County, Pennsylvania. For example, outbreak populations of southern pine beetle are now persistent in New Jersey (21), and mountain pine beetle outbreaks in high elevation forests are continuing at paces not seen over the past century (22). , 1998). [ The phenomenon is: Acid rain, which is caused by SO2 from combustion mixed with atmospheric water vapor. Stephens,5 Kelly Elder,6 Ankur R. Fine root nutrient dynamics were calculated for one year in three high elevation forests of Indian central Himalaya. Proceedings from the Conference on the Ecology and Management of High-Elevation ForestsIn high elevation forest in Pennsylvania ecologists have noticed a serious decline in certain tree species. Google Scholar Schmidt-Vogt D (1990b) Fire in high altitude forests of the Nepal Himalayas. (c) Tropical regions receive. ocean circulation patterns. 8 ha)) forest seeps [ 336 ]. This community occurs around heath woodlands and fens in high-elevation valleys in the White Mountains and the North Country. The highest point in Pennsylvania is Mount Davis, at 3,213 feet (979 meters) above sea level. Since people tend to prefer living in tropical _____ forests and their soils are better for farming, these forests have suffered a greater degree of degradation than tropical _____ forests. Due to wildfire damage in 2016, the true Chimney Tops. Some scientists propose that increased soil acidity might be the cause. The forests of the Allegheny Plateau once comprised. 3. The genus presumably evolved during the Plio-Pleistocene uplift of the. This phenomenon is: Decreased in pH caused by climate change. These changing conditions have significant implications for carbon storage, snowpack, and the. Department of Environmental Science & Policy, University of California, Davis, California 95616 USA. 100 S Main St 300 S Main St 232 Smith St 649 S Broad St 410 Thompson St Jersey Shore Porter Township 347 Oliver St 230 High St 321. LETTER Persistent reduced ecosystem respiration after insect disturbance in high elevation forests David J. The phenomenon is: Acid rain, which is caused by SO2 from combustion mixed with atmospheric water vapor. In high-elevation forests in Pennsylvania, ecologists have noticed a serious decline in certain tree species. tropical forest D. Acid rain, which is caused by SO2 from combustion mixed with. Contour Interval. Weegy. Some scientists propose that increased soil acidity might be the cause. This is a summary of the most current data available describing Pennsylvania’s forest resources. l. 11/20/2023 5:58:08 AM| 5 Answers. Examples of elevation distributions for a a low-elevation species (Black-throated Blue Warbler, Setophaga caerulescens) and b a high-elevation species (Blackpoll Warbler, Setophaga striata). Share sensitive information only on official, secure websites. com is an AI-enabled chat service that observes all of the online support interactions between your call center representatives and customers. The study area is characterized with rugged topography, extreme climatic regime, and a. Linking Remote Sensing and Dendrochronology to Quantify Climate‐Induced Shifts in High‐ Elevation Forests Over Space and Time A. NRS-P-64. This phenomenon is: Decreased in pH caused by climate change. highland C. Abstract Pennsylvania spruce (Picea spp. Some scientists propose that increased soil acidity might be the cause. In high-elevation forests in Pennsylvania, ecologists have noticed a serious decline in certain tree species. Stuttgart. One hypothesis for the lack of coherent responses in growth and resource use efficiency in high-altitude ecosystems is that regional CO 2 and warming effects are secondary to local hydrologic, biogeochemical, and ecological factors (17, 20–23).