Recruitment patterns following a severe drought: long-term compositional shifts in Patagonian forests

2008 ◽  
Vol 38 (12) ◽  
pp. 3002-3010 ◽  
Author(s):  
María L. Suarez ◽  
Thomas Kitzberger
Keyword(s):  
Vegetation Change ◽  
Forest Canopy ◽  
Tree Mortality ◽  
Forest Composition ◽  
Future Climate Change ◽  
Severe Drought ◽  
Climate Change Scenarios ◽  
Recruitment Pattern ◽  
Recruitment Patterns

Severe droughts have the potential of inducing transient shifts in forest canopy composition by altering species-specific adult tree mortality patterns. However, permanent vegetation change will occur only if tree recruitment patterns are also affected. Here, we analyze how a massive mortality event triggered by the 1998–1999 drought affected adult and sapling mortality and recruitment in a mixed Nothofagus dombeyi (Mirb.) Blume – Austrocedrus chilensis (D. Don) Flor. et Boult. forests of northern Patagonia. Comparing drought-induced and tree-fall gaps, we assessed changes in forest composition, microenvironments, and seedling density and survival of both species. Drought-kill disturbance shifted species composition of both canopy and sapling cohorts in favour of A. chilensis. Drought gaps were characterized by a shadier and more xeric environment, affecting the recruitment pattern of N. dombeyi seedlings. The seedling cohort was composed mostly of A. chilensis, and its survival was always higher than that of N. dombeyi. Additionally, A. chilensis seedlings showed higher plasticity than N. dombeyi seedlings, increasing its root to shoot ratios in drought gaps. The results suggest that extreme drought itself is a strong driving force in forest dynamics, with important imprints on forest landscapes. Future climate-change scenarios, projecting an increased in frequency and severity of droughts, alert us about expected long-term compositional shifts in many forest ecosystems.

scholarly journals Water Quality Sustainability Evaluation under Uncertainty: A Multi-Scenario Analysis Based on Bayesian Networks

2019 ◽  
Vol 11 (17) ◽  
pp. 4764 ◽  
Author(s):  
Anna Sperotto ◽  
Josè Luis Molina ◽  
Silvia Torresan ◽  
Andrea Critto ◽  
Manuel Pulido-Velazquez ◽  
...  
Keyword(s):  
Climate Change ◽  
Water Resources ◽  
Bayesian Networks ◽  
Climate Model ◽  
Future Climate Change ◽  
Climate Projections ◽  
Climate Change Scenarios ◽  
Large Variability ◽  
Nutrient Loadings

With increasing evidence of climate change affecting the quality of water resources, there is the need to assess the potential impacts of future climate change scenarios on water systems to ensure their long-term sustainability. The study assesses the uncertainty in the hydrological responses of the Zero river basin (northern Italy) generated by the adoption of an ensemble of climate projections from 10 different combinations of a global climate model (GCM)–regional climate model (RCM) under two emission scenarios (representative concentration pathways (RCPs) 4.5 and 8.5). Bayesian networks (BNs) are used to analyze the projected changes in nutrient loadings (NO3, NH4, PO4) in mid- (2041–2070) and long-term (2071–2100) periods with respect to the baseline (1983–2012). BN outputs show good confidence that, across considered scenarios and periods, nutrient loadings will increase, especially during autumn and winter seasons. Most models agree in projecting a high probability of an increase in nutrient loadings with respect to current conditions. In summer and spring, instead, the large variability between different GCM–RCM results makes it impossible to identify a univocal direction of change. Results suggest that adaptive water resource planning should be based on multi-model ensemble approaches as they are particularly useful for narrowing the spectrum of plausible impacts and uncertainties on water resources.

scholarly journals A Long-Term Record of Quaternary Facies Patterns and Palaeonvironmental Trends from the Po Plain (NE Italy) as Revealed by Bio-Sedimentary Data

Geosciences ◽  
2021 ◽  
Vol 11 (10) ◽  
pp. 401
Author(s):  
Veronica Rossi ◽  
Alessandro Amorosi ◽  
Giulia Barbieri ◽  
Stefano Claudio Vaiani ◽  
Matteo Germano ◽  
...  
Keyword(s):  
Late Pleistocene ◽  
Middle Pleistocene ◽  
Future Climate Change ◽  
Climate Change Scenarios ◽  
Environmental Response ◽  
Alluvial Deposits ◽  
Po Plain ◽  
Ne Italy ◽  
Coastal Marine

Understanding Quaternary dynamics of delta-coastal plains across multiple glacial-interglacial cycles in the Milankovitch band (~100 kyrs) is crucial to achieve a robust evaluation of possible environmental response to future climate-change scenarios. In this work, we document the long-term bio-sedimentary record of core 204 S16 (~205 m long), which covers a wide portion of the post-MPR (Mid-Pleistocene Revolution) interval, taking advantage of the highly subsiding context of the SE Po Plain (NE Italy). Detailed facies characterization through an integrated sedimentological and meiofauna (benthic foraminifers and ostracods) approach allowed for the identification of a repetitive pattern of alluvial deposits alternating with four fossiliferous, paralic to shallow-marine units (Units 1–4). The transgressive surfaces identified at the base of these units mark major flooding events, forced by Holocene (Unit 4), Late Pleistocene (Unit 3) and Middle Pleistocene (Units 1, 2) interglacials. Distinct stratigraphic patterns typify the Middle Pleistocene interval, which includes coastal-marine (tidal inlet and bay) deposits. In contrast, lagoonal sediments record the maximum marine influence in the Late Pleistocene-Holocene succession. As a whole, the meiofauna tracks a regressive trend, with the deepest conditions recorded by the oldest Unit 1 (MIS 9/11 age?).

Differential tree mortality in response to severe drought: evidence for long-term vegetation shifts

2005 ◽  
Vol 93 (6) ◽  
pp. 1085-1093 ◽  
Author(s):  
REBECCA C. MUELLER ◽  
CRESCENT M. SCUDDER ◽  
MARIANNE E. PORTER ◽  
R. TALBOT TROTTER ◽  
CATHERINE A. GEHRING ◽  
...  
Keyword(s):  
Tree Mortality ◽  
Severe Drought ◽  
Vegetation Shifts

scholarly journals Landscape-Scale Forest Reorganization Following Insect Invasion and Harvest Under Future Climate Change Scenarios

Ecosystems ◽  
2021 ◽  
Author(s):  
Stacey K. Olson ◽  
Erica A. H. Smithwick ◽  
Melissa S. Lucash ◽  
Robert M. Scheller ◽  
Robert E. Nicholas ◽  
...  
Keyword(s):  
Climate Change ◽  
Forest Disturbance ◽  
Emerald Ash Borer ◽  
Agrilus Planipennis ◽  
Forest Composition ◽  
Future Climate Change ◽  
Climate Change Scenarios ◽  
Long Term Effects ◽  
Climate Conditions ◽  
Species Dominance

AbstractEmerald ash borer (EAB; Agrilus planipennis Farimaire) has been found in 35 US states and five Canadian provinces. This invasive beetle is causing widespread mortality to ash trees (Fraxinus spp.), which are an important timber product and ornamental tree, as well as a cultural resource for some Tribes. The damage will likely continue despite efforts to impede its spread. Further, widespread and rapid ash mortality as a result of EAB is expected to alter forest composition and structure, especially when coupled with the regional effects of climate change in post-ash forests. Thus, we forecasted the long-term effects of EAB-induced ash mortality and preemptive ash harvest (a forest management mitigation strategy) on forested land across a 2-million-hectare region in northern Wisconsin. We used a spatially explicit and spatially interactive forest simulation model, LANDIS-II, to estimate future species dominance and biodiversity assuming continued widespread ash mortality. We ran forest disturbance and succession simulations under historic climate conditions and three downscaled CMIP5 climate change projections representing the upper bound of expected changes in precipitation and temperature. Our results suggest that although ash loss from EAB or harvest resulted in altered biodiversity patterns in some stands, climate change will be the major driver of changes in biodiversity by the end of century, causing increases in the dominance of southern species and homogenization of species composition across the landscape.

scholarly journals Evaluating Nature-Based Solution for Flood Reduction in Spercheios River Basin under Current and Future Climate Conditions

2021 ◽  
Vol 13 (7) ◽  
pp. 3885
Author(s):  
Christos Spyrou ◽  
Michael Loupis ◽  
Νikos Charizopoulos ◽  
Ilektra Apostolidou ◽  
Angeliki Mentzafou ◽  
...  
Keyword(s):  
Climate Change ◽  
River Basin ◽  
Maximum Velocity ◽  
Weather Conditions ◽  
Future Climate ◽  
Future Climate Change ◽  
Climate Change Scenarios ◽  
Climate Conditions ◽  
The Impact

Nature-based solutions (NBS) are being deployed around the world in order to address hydrometeorological hazards, including flooding, droughts, landslides and many others. The term refers to techniques inspired, supported and copied from nature, avoiding large constructions and other harmful interventions. In this work the development and evaluation of an NBS applied to the Spercheios river basin in Central Greece is presented. The river is susceptible to heavy rainfall and bank overflow, therefore the intervention selected is a natural water retention measure that aims to moderate the impact of flooding and drought in the area. After the deployment of the NBS, we examine the benefits under current and future climate conditions, using various climate change scenarios. Even though the NBS deployed is small compared to the rest of the river, its presence leads to a decrease in the maximum depth of flooding, maximum velocity and smaller flooded areas. Regarding the subsurface/groundwater storage under current and future climate change and weather conditions, the NBS construction seems to favor long-term groundwater recharge.

scholarly journals Impacts of an Extreme Early-Season Freeze Event in the Interior Pacific Northwest (30 October–3 November 2002) on Western Juniper Woodlands

2005 ◽  
Vol 44 (7) ◽  
pp. 1152-1158 ◽  
Author(s):  
Paul A. Knapp ◽  
Peter T. Soulé
Keyword(s):  
Pacific Northwest ◽  
Tree Mortality ◽  
Extended Period ◽  
Severe Drought ◽  
Cold Spell ◽  
Cold Event ◽  
Western Juniper ◽  
Synoptic Conditions ◽  
Temperature Records

Abstract In mid-autumn 2002, an exceptional 5-day cold spell affected much of the interior Pacific Northwest, with minimum temperatures averaging 13°C below long-term means (1953–2002). On 31 October, minimum temperature records occurred at 98 of the 106 recording stations, with records lowered in some locations by 9°C. Calculation of recurrence intervals of minimum temperatures shows that 50% of the stations experienced a >500-yr event. The synoptic conditions responsible were the development of a pronounced high pressure ridge over western Canada and an intense low pressure area centered in the Intermountain West that promoted strong northeasterly winds. The cold spell occurred near the end of the growing season for an ecologically critical and dominant tree species of the interior Pacific Northwest—western juniper—and followed an extended period of severe drought. In spring 2003, it became apparent that the cold had caused high rates of tree mortality and canopy dieback in a species that is remarkable for its longevity and resistance to climatic stress. The cold event altered western juniper dominance in some areas, and this alteration may have long-term impacts on water budgets, fire intensities and frequencies, animal species interrelationships, and interspecific competition among plant species.

scholarly journals Assessment of Ecological and Hydro-Geomorphological Alterations under Climate Change Using SWAT and IAHRIS in the Eo River in Northern Spain

Water ◽  
2020 ◽  
Vol 12 (6) ◽  
pp. 1745
Author(s):  
Julio Pérez-Sánchez ◽  
Javier Senent-Aparicio ◽  
Carolina Martínez Santa-María ◽  
Adrián López-Ballesteros
Keyword(s):  
Climate Change ◽  
General Circulation ◽  
Assessment Tool ◽  
Swat Model ◽  
General Circulation Models ◽  
Future Climate Change ◽  
Climate Change Scenarios ◽  
Efficiency Coefficient ◽  
Northern Spain

Magnitude and temporal variability of streamflow is essential for natural biodiversity and the stability of aquatic environments. In this study, a comparative analysis between historical data (1971–2013) and future climate change scenarios (2010–2039, 2040–2069 and 2070–2099) of the hydrological regime in the Eo river, in the north of Spain, is carried out in order to assess the ecological and hydro-geomorphological risks over the short-, medium- and long-term. The Soil and Water Assessment Tool (SWAT) model was applied on a daily basis to assess climate-induced hydrological changes in the river under five general circulation models and two representative concentration pathways. Statistical results, both in calibration (Nash-Sutcliffe efficiency coefficient (NSE): 0.73, percent bias (PBIAS): 3.52, R2: 0.74) and validation (NSE: 0.62, PBIAS: 6.62, R2: 0.65), are indicative of the SWAT model’s good performance. The ten climate scenarios pointed out a reduction in rainfall (up to −22%) and an increase in temperatures, both maximum (from +1 to +7 °C) and minimum ones (from +1 to +4 °C). Predicted flow rates resulted in an incrementally greater decrease the longer the term is, varying between −5% (in short-term) and −53% (in long-term). The free software IAHRIS (Indicators of Hydrologic Alteration in Rivers) determined that alteration for usual values remains between excellent and good status and from good to moderate in drought values, but flood values showed a deficient regime in most scenarios, which implies an instability of river morphology, a progressive reduction in the section of the river and an advance of aging of riparian habitat, endangering the renewal of the species.

scholarly journals Selecting tree species for climate change integrated forest restoration and management in the Chitwan Annapurna Landscape, Nepal

2020 ◽  
Vol 13 ◽  
pp. 29-46
Author(s):  
Gokarna Jung Thapa ◽  
Eric Wikramanayake
Keyword(s):  
Climate Change ◽  
Tree Species ◽  
Forest Restoration ◽  
Climate Adaptation ◽  
Range Shifts ◽  
Future Climate Change ◽  
Climate Change Scenarios ◽  
The Government ◽  
Choice Of Species

Climate change will affect forest vegetation communities, and field surveys have already indicated measurable distribution range shifts in some tree species. As forests play an important role in stabilizing steep slopes and provide vital ecological goods and services, the Government of Nepal has been encouraging forest restoration and sustainable management. However, reforestation and afforestation programs should consider the long term survivorship of the trees selected for reforestation to build climate adaptation and resilience. Thus, the choice of species should include species that would be expected to grow within the elevation zone or in the particular habitat under future climate change scenarios. In this analysis, we have assessed the response of 12 important tree species to climate change using the IPCC A2A GHG scenario with GCM-based climate envelopes to provide guidelines and recommendations for climate change-integrated forest restoration and management in the Chitwan-Annapurna Landscape (CHAL). The results indicate that several species could exhibit range shifts due to climate change, with an overall trend for species in the lower elevations to move northwards or further up the slopes within the current area of distributions. Analyses such as this, though not perfect, can help to make critical and informed decisions to support long-term forest restoration programs.

scholarly journals Differential impact of severe drought on infant mortality in two sympatric neotropical primates

2020 ◽  
Vol 7 (4) ◽  
pp. 200302 ◽  
Author(s):  
Fernando A. Campos ◽  
Urs Kalbitzer ◽  
Amanda D. Melin ◽  
Jeremy D. Hogan ◽  
Saul E. Cheves ◽  
...  
Keyword(s):  
Infant Mortality ◽  
Tree Mortality ◽  
Natural Populations ◽  
Dry Forest ◽  
Primate Species ◽  
Spider Monkeys ◽  
Severe Drought ◽  
Climate Conditions ◽  
Fruit Abundance

Extreme climate events can have important consequences for the dynamics of natural populations, and severe droughts are predicted to become more common and intense due to climate change. We analysed infant mortality in relation to drought in two primate species (white-faced capuchins, Cebus capucinus imitator, and Geoffroy's spider monkeys, Ateles geoffroyi ) in a tropical dry forest in northwestern Costa Rica. Our survival analyses combine several rare and valuable long-term datasets, including long-term primate life-history, landscape-scale fruit abundance, food-tree mortality, and climate conditions. Infant capuchins showed a threshold mortality response to drought, with exceptionally high mortality during a period of intense drought, but not during periods of moderate water shortage. By contrast, spider monkey females stopped reproducing during severe drought, and the mortality of infant spider monkeys peaked later during a period of low fruit abundance and high food-tree mortality linked to the drought. These divergent patterns implicate differing physiology, behaviour or associated factors in shaping species-specific drought responses. Our findings link predictions about the Earth's changing climate to environmental influences on primate mortality risk and thereby improve our understanding of how the increasing severity and frequency of droughts will affect the dynamics and conservation of wild primates.

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