placeholder
and
and

Your email was sent successfully. Check your inbox.

An error occurred while sending the email. Please try again.

Proceed reservation?

Proceed order?

Export
Filter
Document type
Language
Year
  • 1
    Language: English
    In: The Journal of ecology, 2010-05-01, Vol.98 (3), p.592-603
    Description: 1. Long-term basal area increment (BAI) in Abies pinsapo was studied to investigate the way density-dependent factors modulate the responses of radial growth to climatic stresses in relict stands of a drought-sensitive Mediterranean fir. 2. First, we verified that spatially explicit competition predicts mean A. pinsapo BAI at our study site; i. e. it modulates the degree to which the average climate-driven potential for growth is expressed. Second, we verified that the long-term pattern of temperature predicts the long-term pattern of BAI, estimated as the main trend over a time period of 40 years. Finally, we assessed whether the intensity of tree-to-tree competition restrains the potential improvements achieved by our model of BAI when a short-term, high-frequency Stressor such as drought (inter-annual precipitation variability) is introduced. 3. We applied Dynamic Factor Analysis (DFA) to characterize regional climatic trends and to test thehypothesis that trees subjected to contrasting competition intensity may differ in their growth pattern. Significant long-term climate trends obtained by DFA were used as predictors of long-term BAI. 4. The mean BAI was mainly determined by competition, whereas growth trends obtained by DFA did not differ among dominant, suppressed and dying trees. Common trends of growth decline were strongly related to long-term, late-winter to summer temperatures, while the residuals were related to total annual precipitation, although with decreasing significance as competition increased. Our results support the contention that the reported patterns of A. pinsapo growth decline and death occur as a result of the interacting effects of both competition and climate Stressors acting at longand short-term time scales. 5. Synthesis. Long-term climatic drought stress was the main driving factor of growth decline in A.pinsapo. Moreover, trees already suffering from competition (a long-term stress) were predisposed to decline given an additional short-term stress, such as a severe drought.
    Subject(s): Trees ; Climate change ; Plant-climate interactions ; Tree growth ; Ecological competition ; Mortality ; Forest ecology ; Death ; Climate models ; Drought ; Human ecology ; adaptive capacity ; Abies pinsapo ; global warming ; linear mixed models ; drought ; Dynamic Factor Analysis ; basal area increment ; climatic change ; competition ; vulnerability ; Fundamental and applied biological sciences. Psychology ; General forest ecology ; General aspects ; Animal, plant and microbial ecology ; Forestry ; Biological and medical sciences ; Animal and plant ecology ; Generalities. Production, biomass. Quality of wood and forest products. General forest ecology ; Climate ; Precipitation variability ; Droughts ; Analysis ; Global warming ; Rain and rainfall ; Statistics
    ISSN: 0022-0477
    E-ISSN: 1365-2745
    Source: JSTOR Arts & Sciences I
    Source: Elektronische Zeitschriftenbibliothek - Frei zugängliche E-Journals
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 2
    Language: English
    In: Global change biology, 2018-11, Vol.24 (11), p.5549-5559
    Description: Among forest ecosystems, the alpine treeline ecotone can be considered to be a simplified model to study global ecology and climate change. Alpine treelines are expected to shift upwards in response to global warming given that tree recruitment and growth are assumed to be mainly limited by low temperatures. However, little is known whether precipitation and temperature interact to drive long‐term Himalayan treeline dynamics. Tree growth is affected by spring rainfall in the central Himalayan treelines, being good locations for testing if, in addition to temperature, precipitation mediates treeline dynamics. To test this hypothesis, we reconstructed spatiotemporal variations in treeline dynamics in 20 plots located at six alpine treeline sites, dominated by two tree species (birch, fir), and situated along an east–west precipitation gradient in the central Himalayas. Our reconstructions evidenced that treelines shifted upward in response to recent climate warming, but their shift rates were primarily mediated by spring precipitation. The rate of upward shift was higher in the wettest eastern Himalayas, suggesting that its ascent rate was facilitated by spring precipitation. The drying tendency in association with the recent warming trends observed in the central Himalayas, however, will likely hinder an upslope advancement of alpine treelines and promote downward treeline shifts if moisture availability crosses a critical minimum threshold. Our study highlights the complexity of plant responses to climate and the need to consider multiple climate factors when analyzing treeline dynamics. Based on 20 treeline plots along an east–west precipitation gradient in the central Himalayas, this research showed that treelines shifted upward in response to recent climate warming, but their shift rates were mediated by spring precipitation. The drying tendency in association with the recent warming trends observed in the central Himalayas, however, will likely hinder an upslope advancement of alpine treelines and promote downward treeline shifts if moisture availability crosses a critical minimum threshold. Our study highlights the complexity of plant responses to climate and the need to consider multiple climate factors when analyzing treeline dynamics.
    Subject(s): central Himalayas ; treeline shift ; Alpine treeline ; tree recruitment ; climate change ; Global Warming ; Rain ; Trees - physiology ; Time Factors ; Nepal ; Altitude ; Plant Dispersal ; Analysis ; Alpine ecosystems ; Mountain ecology ; Environmental aspects ; Air pollution ; Global warming ; Rain and rainfall ; Index Medicus
    ISSN: 1354-1013
    E-ISSN: 1365-2486
    Source: Alma/SFX Local Collection
    Source: © ProQuest LLC All rights reserved〈img src="https://exlibris-pub.s3.amazonaws.com/PQ_Logo.jpg" style="vertical-align:middle;margin-left:7px"〉
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 3
    Language: English
    In: Trees (Berlin, West), 2014-12, Vol.28 (6), p.1737-1750
    Description: The retrospective analysis of wood anatomical features evidences how a long-term deterioration of hydraulic performance and carbon use portend drought-induced mortality in Scots pine. Widespread episodes of drought-induced tree mortality are predicted to become more frequent as climate becomes warmer and drier. Nevertheless, growth trends and their links to changes in wood anatomy before tree dies are still poorly understood. Wood anatomical features provide valuable information that can be extracted to infer the mechanisms leading to tree death. In this study, we characterize drought-induced mortality affecting two Scots pine (Pinus sylvestris) sites (Prades and Arcalís) located in the North Eastern Iberian Peninsula. Co-occurring now-dead and living Scots pine trees were sampled and their wood anatomical features were measured and compared. We aimed to detect differences in anatomical features between living and dead trees, and to infer past physiological performances that might have determined their subsequent death or survival. Now-dead trees showed lower tracheid and resin duct production, and smaller radial lumen diameters than co-occurring living trees. At the more xeric Prades site, these anatomical differences were larger and chronic, i.e. were observed over the three studied decades, whilst they were less pronounced at the other, more mesic Arcalís site, where tree mortality episodes were more recent. This indicates that dead trees’ hydraulic conductivity was severely affected and that carbon investment in xylem formation and resin duct production was constrained prior to tree death. Our findings show that both hydraulic deterioration and low carbon allocation to xylem formation were associated to drought-induced mortality in Scots pine. Nevertheless, the temporal dynamics of these processes differed between populations as a function of site climatic conditions.
    Subject(s): Plant Anatomy/Development ; Scots pine ; Mortality ; Wood anatomy ; Plant Physiology ; Tracheid ; Life Sciences ; Plant Pathology ; Tree ring ; Forestry ; Agriculture ; Drought ; Plant Sciences ; Dendroclimatology ; Hydrogeology ; Investments ; Droughts ; Analysis ; Physiological aspects ; Health aspects
    ISSN: 0931-1890
    E-ISSN: 1432-2285
    Source: Alma/SFX Local Collection
    Source: ProQuest Central
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 4
    Language: English
    In: Annals of botany, 2014-08-01, Vol.114 (2), p.301-313
    Description: • Background and Aims Several studies show apparently contradictory findings about the functional convergence within the Mediterranean woody flora. In this context, this study evaluates the variability of functional traits within holm oak (Quercus ilex) to elucidate whether provenances corresponding to different morphotypes represent different ecotypes locally adapted to the prevaling stress levels. • Methods Several morphological and physiological traits were measured at leaf and shoot levels in 9-year-old seedlings of seven Q. ilex provenances including all recognized morphotypes. Plants were grown in a common garden for 9 years under the same environmental conditions to avoid possible biases due to site-specific characteristics. • Key Results Leaf morphometry clearly separates holm oak provenances into 'ilex' (more elongated leaves with low vein density) and 'rotundifolia' (short and rounded leaves with high vein density) morphotypes. Moreover, these morphotypes represent two consistent and very contrasting functional types in response to dry climates, mainly in terms of leaf area, major vein density, leaf specific conductivity, resistance to drought-induced cavitation and turgor loss point. • Conclusions The 'ilex' and 'rotundifolia' morphotypes correspond to different ecotypes as inferred from their contrasting functional traits. To the best of our knowledge, this is the first time that the combined use of morphological and physiological traits has provided support for the concept of these two holm oak morphotypes being regarded as two different species.
    Subject(s): Oak trees ; Provenance ; Xylem ; Turgor pressure ; Hydraulics ; Plant morphology ; Cavitation flow ; Vascular plants ; Leaf area ; Drought ; Geography ; Climate ; Quantitative Trait, Heritable ; Biodiversity ; Pressure ; Quercus - anatomy & histology ; Droughts ; Plant Leaves - anatomy & histology ; Ecotype ; Mediterranean Region ; Principal Component Analysis ; Plant Leaves - physiology ; Quercus - physiology ; Index Medicus ; ‘ilex’ morphotype ; palaeobotany ; Mediterranean vegetation ; 1002 ; functional traits ; holm oak ; ‘rotundifolia’ morphotype ; Quercus ilex ; ecotype ; Original
    ISSN: 0305-7364
    E-ISSN: 1095-8290
    Source: Academic Search Ultimate
    Source: PubMed Central
    Source: Alma/SFX Local Collection
    Source: Oxford Journals 2016 Current and Archive A-Z Collection
    Source: © ProQuest LLC All rights reserved〈img src="https://exlibris-pub.s3.amazonaws.com/PQ_Logo.jpg" style="vertical-align:middle;margin-left:7px"〉
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 5
    Language: English
    In: Journal of biogeography, 2014-06-01, Vol.41 (6), p.1105-1114
    Description: Aim The Mediterranean Basin is considered to be a climate-change hotspot, for which rising temperatures and associated aridification have been forecast. Such trends could affect the performance and growth of conifers in these drought-prone areas. We evaluated whether radial growth and wood density can act as proxy measures of precipitation and drought in a Mediterranean conifer. Location Iberian Juniperus thurifera forests in northern and eastern Spain. Methods We sampled 10 stands encompassing J. thurifera's distributional area. We related four annually resolved tree-ring variables (earlywood and latewood width, and maximum and minimum wood density) to climatic factors (temperature, precipitation and drought index) for the period 1951–2000. We then analysed the spatial and temporal patterns of those associations. Results Of all the four tree-ring variables analysed, minimum wood density presented the strongest response to climate. Higher values of minimum wood density were related to drier spring conditions, particularly in the most xeric sites, confirming that a drought-induced reduction in the radial expansion of tracheids increases earlywood density. Main conclusions Minimum wood density is a biogeographically meaningful proxy of spring water availability for the Mediterranean conifer J. thurifera.
    Subject(s): Dendroclimatology ; Precipitation ; Tracheids ; Earlywood ; Plant–environment relationships ; Wood density ; Seasons ; Pine trees ; Drought ; Growth rings ; Latewood ; drought ; Climate proxy ; wood density ; dendroecology ; dendroclimatology ; Juniperus thurifera ; conifer ; Mediterranean climate ; Spain ; Fundamental and applied biological sciences. Psychology ; Biological and medical sciences ; General aspects ; Synecology ; Animal and plant ecology ; Animal, plant and microbial ecology ; Water ; Paleoclimatology ; Climate ; Proxy ; Specific gravity ; Climatic changes ; Precipitation (Meteorology)
    ISSN: 0305-0270
    E-ISSN: 1365-2699
    Source: Alma/SFX Local Collection
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 6
    Language: English
    In: Trees (Berlin, West), 2009-08, Vol.23 (4), p.787-799
    Description: This study analyses how coexisting evergreen and deciduous oaks adjust their phenology to cope with the stressful Mediterranean summer conditions. We test the hypothesis that the vegetative and reproductive growth of the winter deciduous (Quercus faginea Lam.) is more affected by summer drought than that of the evergreen [Quercus ilex L. subsp. ballota (Desf.) Samp.]. First, we assessed the complete aboveground phenology of both species during two consecutive years. Shoot and litter production and bud, acorn and secondary growth were monitored monthly. Second, we identified several parameters affected by summer conditions: apical bud size, individual leaf area (LA), leaf mass per area (LMA) and acorn yield in both species, and leaf-fall in Q. faginea and analysed their variation over 10 years. Q. ilex performed up to 25% of shoot growth and most leaf development during summer, whereas Q. faginea completed most of both phenophases during spring. Secondary growth was arrested in summer under drought conditions. Approximately, 30--40% of bud and 40--50% of acorn growth was undertaken during summer in both species. Summer drought related to differences in LA, LMA and leaf senescence, but not to acorn yield. Both species had similar year-to-year patterns of acorn production, though yields were always lower in Q. faginea. Bud size decreased severely in both species during extremely dry years. In Q. ilex, bud size tended to alternate between years of large and small buds, and these patterns were followed by opposite trends in stem length. In Q. faginea, bud size was more stable through time. Q. ilex was more phenologically active during summer than Q. faginea, indicating a higher tolerance to drought. Furthermore, bud and fruit growth (the only two phenophases that both species performed during summer) were more severely affected by summer drought in Q. faginea than in the evergreen. The differential effects of summer drought on key phenophases for the persistence (bud growth) and colonization ability (fruit production) of both species may have consequences for their coexistence.
    Subject(s): Droughts
    ISSN: 0931-1890
    E-ISSN: 1432-2285
    Source: Alma/SFX Local Collection
    Source: ProQuest Central
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 7
    Language: English
    In: Proceedings of the National Academy of Sciences - PNAS, 2013-01-02, Vol.110 (1), p.52-57
    Description: We evaluated the response of the Earth land biomes to drought by correlating a drought index with three global indicators of vegetation activity and growth: vegetation indices from satellite imagery, treering growth series, and Aboveground Net Primary Production (ANPP) records. Arid and humid biomes are both affected by drought and we suggest that the persistence of the water deficit (i.e., the drought timescale) could be playing a key role in determining the sensitivity of land biomes to drought. We found that arid biomes respond to drought at short time-scales; that is, there is a rapid vegetation reaction as soon as water deficits below normal conditions occur. This may be due to the fact that plant species of arid regions have mechanisms allowing them to rapidly adapt to changing water availability. Humid biomes also respond to drought at short time-scales, but in this case the physiological mechanisms likely differ from those operating in arid biomes, as plants usually have a poor adaptability to water shortage. On the contrary, semiarid and subhumid biomes respond to drought at long timescales, probably because plants are able to withstand water deficits, but they lack the rapid response of arid biomes to drought. These results are consistent among three vegetation parameters analyzed and across different land biomes, showing that the response of vegetation to drought depends on characteristic drought time-scales for each biome. Understanding the dominant time-scales at which drought most influences vegetation might help assessing the resistance and resilience of vegetation and improving our knowledge of vegetation vulnerability to climate change.
    Subject(s): Datasets ; Climate change ; Vegetation index ; Vegetation ; Biomes ; Water balance ; Plants ; Drought ; Growth rings ; Tropical rain forests ; Fundamental and applied biological sciences. Psychology ; Biological and medical sciences ; Synecology ; Terrestrial ecosystems ; Animal and plant ecology ; Animal, plant and microbial ecology ; Geography ; Time Factors ; Droughts ; Biota ; Photosynthesis - physiology ; Spacecraft ; Plant Physiological Phenomena ; Trees - growth & development ; Plant Stems - growth & development ; Environmental aspects ; Agricultural productivity ; Vegetation dynamics ; Research ; United States ; Index Medicus ; Biological Sciences ; drought index ; Physical Sciences ; drought adaptation ; drought impacts ; NDVI ; Standardized Precipitation Evapotranspiration Index
    ISSN: 0027-8424
    E-ISSN: 1091-6490
    Source: HighWire Press (Free Journals)
    Source: Hellenic Academic Libraries Link
    Source: PubMed Central
    Source: © ProQuest LLC All rights reserved〈img src="https://exlibris-pub.s3.amazonaws.com/PQ_Logo.jpg" style="vertical-align:middle;margin-left:7px"〉
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 8
    Language: English
    In: Theoretical and applied climatology, 2015-08, Vol.121 (3), p.571-579
    Description: Atlantic and Mediterranean air masses influence the climate over the Iberian System mountain range. The relatively short instrumental records in central Spain though limit any long-term assessment of these synoptic systems. We here evaluate the potential to analyze such changes using ring width data from Juniperus thurifera trees growing in the northwestern and southeastern regions of the Iberian System, exposed to Atlantic and Mediterranean cyclonic activity, respectively. Comparison of tree rings with regional precipitation, temperature, and Palmer Drought Severity Index (PDSI) data indicates that juniper trees contain information on late spring and early summer drought conditions. Calibration trials using spatially resolved, gridded climate data reveal that the northwestern sampling site is predominantly controlled by Atlantic weather, while the southeastern site mainly reflects Mediterranean climate patterns. The strength and position of the blocking Azores high during spring to early summer is of particular importance for the distinct growth reactions in the Iberian System. The climate signal is remarkably strong in the southeastern site, where we developed the longest and best-replicated juniper tree ring record of the Iberian Peninsula. Data from this site allowed the reconstruction of May-June PDSI variability back to the early eighteenth century, indicating severe drought (PDSI 〈 −9) in southeastern Spain in 1782, 1828, 1869, 1981, and 2005. The new PDSI record coheres well with historical rogation ceremony data from eastern Spain, indicating that common information on past drought events is inherent in both proxy archives.
    Subject(s): Climatology ; Earth Sciences ; Atmospheric Sciences ; Waste Water Technology / Water Pollution Control / Water Management / Aquatic Pollution ; Atmospheric Protection/Air Quality Control/Air Pollution ; Automobile drivers ; Precipitation (Meteorology) ; Rites, ceremonies and celebrations ; Droughts ; Analysis
    ISSN: 0177-798X
    E-ISSN: 1434-4483
    Source: Academic Search Ultimate
    Source: Alma/SFX Local Collection
    Source: © ProQuest LLC All rights reserved〈img src="https://exlibris-pub.s3.amazonaws.com/PQ_Logo.jpg" style="vertical-align:middle;margin-left:7px"〉
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 9
    Language: English
    In: Global change biology, 2020-02, Vol.26 (2), p.e1-e3
    Description: This article is a response to Zang et al., 26, 322–324.
    Subject(s): Water ; Benchmarking ; Ecology ; Droughts ; Ecosystem ; Index Medicus
    ISSN: 1354-1013
    E-ISSN: 1365-2486
    Source: Alma/SFX Local Collection
    Source: © ProQuest LLC All rights reserved〈img src="https://exlibris-pub.s3.amazonaws.com/PQ_Logo.jpg" style="vertical-align:middle;margin-left:7px"〉
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 10
    Language: English
    In: Global change biology, 2019-08, Vol.25 (8), p.2825-2840
    Description: The mechanisms translating global circulation changes into rapid abrupt shifts in -forest carbon capture in semi-arid biomes remain poorly understood. Here, we report -unprecedented multidecadal shifts in forest carbon uptake in semi-arid Mediterranean pine forests in Spain over 1950-2012. The averaged carbon sink reduction varies between 31% and 37%, and reaches values in the range of 50% in the most affected forest stands. Regime shifts in forest carbon uptake are associated with climatic early warning signals, decreased forest regional synchrony and reduced long-term carbon sink resilience. We identify the mechanisms linked to ocean multidecadal variability that shape regime shifts in carbon capture. First, we show that low-frequency variations of the surface temperature of the Atlantic Ocean induce shifts in the nonstationary effects of El Nino Southern Oscillation (ENSO) on regional forest carbon capture. Modelling evidence supports that the non-stationary effects of ENSO can be propagated from tropical areas to semi-arid Mediterranean biomes through atmospheric wave trains. Second, decadal changes in the Atlantic Multidecadal Oscillation (AMO) significantly alter sea-air heat exchanges, modifying in turn ocean vapour transport over land and land surface temperatures, and promoting sustained drought conditions in spring and summer that reduce forest carbon uptake. Third, we show that lagged effects of AMO on the winter North Atlantic Oscillation also contribute to the maintenance of long-term droughts. Finally, we show that the reported strong, negative effects of ocean surface temperature (AMO) on forest carbon uptake in the last decades are unprecedented over the last 150 years. Our results provide new, unreported explanations for carbon uptake shifts in these drought-prone forests and review the expected impacts of global warming on the profiled mechanisms.
    Subject(s): forest ; regime shift ; TREE GROWTH ; PACIFIC ; DROUGHT ; LARGE-SCALE ; climate ; SEMIARID ECOSYSTEMS ; OSCILLATION ; VARIABILITY ; NORTH-ATLANTIC ; carbon sink ; EUROPEAN CLIMATE ; PINUS-HALEPENSIS ; resilience ; multidecadal drought ; North Atlantic oscillation ; Climate ; Climate cycles ; Analysis ; Biomes ; Ocean ; Global warming ; Environmental Sciences
    ISSN: 1354-1013
    E-ISSN: 1365-2486
    Source: Alma/SFX Local Collection
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
Close ⊗
This website uses cookies and the analysis tool Matomo. More information can be found here...