scholarly journals Climate-induced reversal of tree growth patterns at a tropical treeline

2021 ◽  
Vol 7 (22) ◽  
pp. eabb7572
Author(s):  
Paulo Quadri ◽  
Lucas C. R. Silva ◽  
Erika S. Zavaleta
Keyword(s):  
Tree Growth ◽  
Global Environmental Change ◽  
High Elevation ◽  
Growth Patterns ◽  
Growth Responses ◽  
The Past ◽  
Landscape Processes ◽  
Global Environmental ◽  
Isotopic Methods ◽  
High Elevation Forest

Globally, cold-limited trees and forests are expected to experience growth acceleration as a direct response to warming temperatures. However, thresholds of temperature limitation may vary substantially with local environmental conditions, leading to heterogeneous responses in tree ecophysiology. We used dendroecological and isotopic methods to quantify shifting tree growth and resource use over the past 143 years across topographic aspects in a high-elevation forest of central Mexico. Trees on south-facing slopes (SFS) grew faster than those on north-facing slopes (NFS) until the mid-20th century, when this pattern reversed notably with marked growth rate declines on SFS and increases on NFS. Stable isotopes of carbon, oxygen, and carbon-to-nitrogen ratios suggest that this reversal is linked to interactions between CO2 stimulation of photosynthesis and water or nitrogen limitation. Our findings highlight the importance of incorporating landscape processes and habitat heterogeneity in predictions of tree growth responses to global environmental change.

The Archaeology of Global Environment Change

2013 ◽  
Author(s):  
Carole L. Crumley
Keyword(s):  
Human Activity ◽  
Global Environmental Change ◽  
Earth System ◽  
Human Environment ◽  
The Past ◽  
The Earth ◽  
Global Environmental ◽  
Urgent Task ◽  
The Two Cultures ◽  
Non Linear System

Recent, widely recognized changes in the Earth system are, in effect, changes in the coupled human–environment system. We have entered the Anthropocene, when human activity—along with solar forcing, volcanic activity, precession, and the like—must be considered a component (a ‘driver’) of global environmental change (Crutzen and Stoermer 2000; Levin 1998). The dynamic non-linear system in which we live is not in equilibrium and does not act in a predictable manner (see Fairhead, chapter 16 this volume for further discussion of non-equilibrium ecology). If humankind is to continue to thrive, it is of utmost importance that we identify the ideas and practices that nurture the planet as well as our species. Our best laboratory for this is the past, where long-, medium-, and short-term variables can be identified and their roles evaluated. Perhaps the past is our only laboratory: experimentation requires time we no longer have. Thus the integration of our understanding of human history with that of the Earth system is a timely and urgent task. Archaeologists bring two particularly useful sets of skills to this enterprise: how to collaborate, and how to learn from the past. Archaeology enjoys a long tradition of collaboration with colleagues in both the biophysical sciences and in the humanities to investigate human activity in all planetary environments. Archaeologists work alongside one another in the field, live together in difficult conditions, welcome collaboration with colleagues in other disciplines—and listen to them carefully—and tell compelling stories to an interested public. All are rare skills and precious opportunities. Until recently few practitioners of biophysical, social science, and humanities disciplines had experience in cross-disciplinary collaboration. Many scholars who should be deeply engaged in collaboration to avert disaster (for example, specialists in tropical medicine with their counterparts in land use change) still speak different professional ‘languages’ and have very different traditions of producing information. C. P. Snow, in The Two Cultures (1993 [1959]), was among the first to warn that the very structure of academia was leading to this serious, if unintended, outcome.

scholarly journals Extreme Growth Increments Reveal Local and Regional Climatic Signals in Two Pinus pinaster Populations

2021 ◽  
Vol 12 ◽  
Author(s):  
Joana Vieira ◽  
Cristina Nabais ◽  
Filipe Campelo
Keyword(s):  
Tree Growth ◽  
Pinus Pinaster ◽  
Sand Dunes ◽  
Management Strategies ◽  
Climatic Conditions ◽  
Growth Patterns ◽  
Growth Responses ◽  
Growth Increments ◽  
Average Precipitation ◽  
Serra Da Estrela

Tree rings are valuable proxies of past climate that allow inferring past growth responses to climate variability and extreme events, which is only possible considering that the relationship between tree growth and environmental conditions is linear and stable over time. However, in the last decades, divergent growth patterns have been observed in trees from the same forest stand, while unprecedented growth convergence was observed between trees from distant locations. Here, we use a new approach that considers convergent and divergent event years in two populations of Pinus pinaster Aiton in an altitudinal and oceanic-continental gradient to investigate what is triggering divergence and convergence in tree growth. The two study sites are Tocha (TCH), a plantation on sand dunes at low altitude near the ocean, and Serra da Estrela (SdE), a mountain plantation located at 1,100 m altitude, 100 km away from the ocean. The analysis of the climatic conditions in convergent growth years revealed that positive convergent growth was related to above average precipitation in previous winter and that negative convergent growth was related to below average precipitation during the growing season. Divergent growth revealed a temperature signal with warmer temperatures in spring promoting growth in SdE and growth reduction in TCH. Convergent growth was associated with a regional climatic signal, reinforcing the importance of precipitation in the Mediterranean region, and divergent growth to site conditions, revealing local adaptation. The information gathered in this study gives valuable insights on the response of P. pinaster to extreme climatic events, allowing for more adjusted management strategies of Mediterranean pine forests.

scholarly journals Principal Factors Influencing Tree Growth in Low-Lying Mid Atlantic Coastal Forests

Forests ◽  
2021 ◽  
Vol 12 (10) ◽  
pp. 1351
Author(s):  
LeeAnn Haaf ◽  
Salli F. Dymond ◽  
Danielle A. Kreeger
Keyword(s):  
Loblolly Pine ◽  
Tree Growth ◽  
Partial Correlation ◽  
Coastal Flooding ◽  
Growth Patterns ◽  
Water Levels ◽  
Growth Responses ◽  
Coastal Forests ◽  
Flood Exposure ◽  
Correlation Tests

Flood frequencies in coastal forests are increasing as sea level rise accelerates from 3–4 mm year−1 to possibly more than 10 mm year−1 by the end of this century. As flooding increases, coastal forests retreat, ghost forests form, and coastal marshes migrate inland. The existence of ghost forests makes the mechanism of forest retreat clear: low-lying trees become more exposed to coastal flooding until they ultimately die. Variability in these retreat rates, however, makes it difficult to predict where and when retreat will continue to occur. Understanding tree growth responses to tidal water levels relative to other environmental factors is a critical step in elucidating the factors that influence retreat variability. Here, dendrochronology was used to study factors that contribute to variations in growth patterns in four coastal forests fringing the Delaware and Barnegat Bays. Species chosen for study included loblolly pine (Pinus taeda), pitch pine (Pinus rigida), and American holly (Ilex opaca). Pearson’s and partial correlation tests showed that growth relationships with monthly environmental conditions varied across sites and were moderate in strength (generally R < 0.5), but each site had at least one significant growth-water level correlation. As coastal flooding exposure is spatially dependent, tree chronologies were also separated into high and low elevation groups. Pearson’s and partial correlation tests of the mean differences between elevation groups showed that at some sites, low elevation trees grew less than high elevation trees when water levels were high, as might be expected. At one site, however, lower elevation trees grew more when water levels were higher, which suggests that other interacting factors—regardless of current flood exposure—potentially have positive, yet likely temporary, influence over tree growth in these low-lying areas.

scholarly journals Leung Receives 2019 Bert Bolin Global Environmental Change Award

Eos ◽  
2020 ◽  
Vol 101 ◽  
Author(s):  
Keyword(s):  
Environmental Change ◽  
San Francisco ◽  
Global Environmental Change ◽  
Transdisciplinary Research ◽  
Fall Meeting ◽  
The Past ◽  
Global Environmental

L. Ruby Leung has been selected as the 2019 Bert Bolin awardee and lecturer of the AGU Global Environmental Change section. She received the award and presented this lecture at AGU’s Fall Meeting 2019, held 9–13 December in San Francisco, Calif. The award recognizes an Earth scientist for “groundbreaking research and/or leadership in global environmental change through cross-disciplinary, interdisciplinary, and transdisciplinary research in the past 10 years.”

scholarly journals Divergent Growth Responses to Warming between Stand-Grown and Open-Grown Trees in a Dryland Montane Forest in Northwestern China

Forests ◽  
2019 ◽  
Vol 10 (12) ◽  
pp. 1133 ◽  
Author(s):  
Lei Zhang ◽  
Hao Shi ◽  
Pengtao Yu ◽  
Yanhui Wang ◽  
Shufen Pan ◽  
...  
Keyword(s):  
Climate Change ◽  
Tree Growth ◽  
Elevation Gradient ◽  
Montane Forest ◽  
Growth Patterns ◽  
Forest Growth ◽  
Northwestern China ◽  
Growth Responses ◽  
Internal Factors ◽  
High Elevations

Dryland montane forests conserve water for people living in the fluvial plains. The fate of these forests under climate warming is strongly affected by local environmental factors. The question remains of how internal factors contribute to climate change impacts on forest growth in these regions. Here, we investigated tree ring records for similar-aged stand-grown trees and their neighboring open-grown trees at elevation in a dryland montane forest (Picea crassifolia Kom.) in northwestern China. The growth rate of open-grown trees is much higher than their neighboring stand-grown trees across the entire elevation gradient, and the lower the altitude, the greater the difference. Open-grown trees at different elevations showed similar growth patterns, as tree growth at all sites was accelerated over time. In contrast, growth patterns of stand-grown trees were divergent at different altitudes, as growth at high elevations (3100–3300 m a.s.l.) was accelerated, whereas growth at low elevations (2700–2900 m a.s.l.) became stable after the year 1990. Analysis of growth–climate relationships indicated that warming promoted open-grown tree growth across the entire altitude gradient, and also stand-grown tree growth at high elevations, but negatively affected the growth of stand-grown trees at low elevations. Water scarcity can be exacerbated by competition within forests, inhibiting the warming-induced benefits on tree growth. Moving window correlation analysis suggested the negative effect of warming on tree growth at low elevations was diminished after the late 1990s, as the drought stress was alleviated. Our research shows the divergent growth responses to warming of stand-grown and open-grown trees along elevation. It reveals effects of internal factors in determining tree growth response to warming and holds the potential to aid forest management and ecosystem models in responding to climate change.

scholarly journals Neelin Receives 2017 Bert Bolin Global Environmental Change Award

Eos ◽  
2017 ◽  
Author(s):  
Keyword(s):  
Focus Group ◽  
Environmental Change ◽  
New Orleans ◽  
Global Environmental Change ◽  
Transdisciplinary Research ◽  
Fall Meeting ◽  
The Past ◽  
Global Environmental ◽  
American Geophysical

J. David Neelin has been selected as the 2017 Bert Bolin awardee and lecturer of the American Geophysical Union's Global Environmental Change focus group. He will receive the award and present this lecture at the 2017 AGU Fall Meeting, to be held 11–15 December in New Orleans, La. The award recognizes an Earth scientist for “groundbreaking research or/and leadership in global environmental change through cross-disciplinary, interdisciplinary, and transdisciplinary research in the past 10 years.”

The Emergence of Enlightened Anthropocentrism in Ecological Restoration

2012 ◽  
Vol 7 (1) ◽  
pp. 48-71 ◽  
Author(s):  
Jozef Keulartz
Keyword(s):  
Climate Change ◽  
Environmental Change ◽  
Ecological Restoration ◽  
Global Environmental Change ◽  
Well Being ◽  
Ecological Design ◽  
New Approach ◽  
The Past ◽  
Long Run ◽  
Global Environmental

Over the past decade a shift can be noticed from ecological restoration to ecological design, where ecological design stands for a technocratic approach that courts hubris and mastery rather than humility and self-restraint. Following Eric Higgs, this shift can be seen as a “hyperactive and heedless response“ to global environmental change, especially climate change. The new technocratic approach may be best characterized as enlightened (or prudential) anthropocentrism, where nature is only allowed that degree of agency which is required to deliver the services that are essential for human well-being. It is not only questionable if we have the scientific and technical abilities to purposeful design ecosystems that will serve our needs, but also if the new approach will be sufficient to protect biodiversity in the long run.

Regional and ecological patterns in interior Douglas-fir climate–growth relationships in British Columbia, Canada

2010 ◽  
Vol 40 (2) ◽  
pp. 308-321 ◽  
Author(s):  
Hardy P. Griesbauer ◽  
D. Scott Green
Keyword(s):  
Climate Change ◽  
British Columbia ◽  
High Elevation ◽  
Climatic Conditions ◽  
Douglas Fir ◽  
Growth Patterns ◽  
Growth Responses ◽  
Study Region ◽  
Tree Ring Data ◽  
Dry Climates

How climate change will affect tree growth across species’ geographic and climatic ranges remains a critical knowledge gap. Tree-ring data were analyzed from 33 interior Douglas-fir ( Pseudotsuga menziesii var. glauca (Beissn.) Franco) stands spanning wide geographic and climatic conditions in the interior of British Columbia to gain insights into how within-species growth responses to climate can vary based on local environmental conditions over a broad climatic and geographic range, including populations growing at the species’ range and climatic margins. Populations growing in relatively warm and dry climates had growth patterns correlated mostly with annual precipitation, whereas populations growing in high-elevation wet and cold climates had growth patterns correlated with snowfall, winter and annual temperatures, and ocean–atmosphere climate systems. Populations growing at climatic extremes (e.g., coldest, driest, warmest) in each study region had the strongest responses to climate. Projected climate change may negatively influence Douglas-fir productivity across most of its range, and populations growing near the species’ climatic limits may provide early and strong indications of future responses.

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