Exploring the climate signal in tree-ring density of Clanwilliam cedar, South Africa

2020 ◽  
Author(s):  
Valerie Trouet ◽  
Tom De Mil ◽  
Matthew Meko ◽  
Jan Van den Bulcke
Keyword(s):  
South Africa ◽  
Tree Ring ◽  
Southern Africa ◽  
Ring Width ◽  
Future Climate Change ◽  
Spring Precipitation ◽  
Climate Signal ◽  
Climatic Signal ◽  
X Ray Computed ◽  
Instrumental Records

<p>High-resolution annual precipitation and temperature proxies are largely lacking in Southern Africa, partly due to the scarcely available tree species that are suitable for dendrochronology. Clanwilliam cedar (Widdringtonia cedarbergensis) from Cape Province, South Africa, is a long-lived conifer with distinct tree rings and thus a strong dendroclimatic potential. However, the climatic signal in its tree-ring width (TRW) is weak and other tree-ring parameters such as density need to be explored to extract climatic information from this proxy. Here we investigate the climatic signal of density parameters in 17 Clanwilliam cedar samples (9 trees) collected in 1978 (Dunwiddie & LaMarche, 1980). We use a non-destructive X-ray Computed Tomography facility to develop minimum density (MIND) and maximum density (MXD) chronologies from 1900 until 1977. EPS for both density series exceeded 0.85. For the period 1930-1977 (reliable instrumental records), MIND correlates negatively with early-growing season precipitation (Oct-Nov), whereas MXD correlates negatively with end-of-season (March) temperature. The spatial correlation between MIND and spring precipitation spans the winter rainfall zone of South Africa. Clanwilliam cedar can live to be 356 years old and the current TRW chronology extends to 1564 CE. Full-length density chronologies for this long-lived species could provide a precipitation reconstruction for southern Africa, a region where historical climate observations are limited and where societal vulnerability to future climate change is high.</p><p>References:</p><p>Dunwiddie, P. W., & LaMarche, V. C. (1980). A climatically responsive tree-ring record from Widdringtonia cedarbergensis, Cape Province, South Africa. Nature, 286(5775), 796–797.</p>

Climate relationships with tree-ring width and δ13C of three Callitris species from semiarid woodlands in south-western Australia

2010 ◽  
Vol 58 (3) ◽  
pp. 175 ◽  
Author(s):  
Ciaran Sgherza ◽  
Louise E. Cullen ◽  
Pauline F. Grierson
Keyword(s):  
Tree Ring ◽  
Western Australia ◽  
Water Conservation ◽  
Ring Width ◽  
Principal Component ◽  
Conservation Strategy ◽  
Sampling Effort ◽  
Climatic Signal ◽  
Old Trees ◽  
Instrumental Records

Proxy measures of climate based on tree rings can allow reconstruction of climate back past the limit of instrumental records, thereby improving understanding of natural climate variability. We assessed the dendroclimatic potential of tree-ring widths and δ13C of three broadly co-occurring species of Callitris in south-western Western Australia. Ring width chronologies of C. columellaris F.Muell., C. canescens (Parl.) S.T. Blake and C. preissii Miq. met standard measures of dendrochronological acceptability. For all three species, the Expressed Population Signal (EPS) was >0.93 and mean correlations between series in each chronology was >0.79. In contrast, δ13C chronologies were of poorer statistical quality (EPS ranged 0.59 to 0.88, mean correlations ranged 0.33 to 0.65) with both less year-to-year and lower-frequency information (lower mean sensitivity and standard deviation values). The dominant climatic signal in the ring width chronologies was related to rainfall and was strongest over the March–September season (correlations ranged 0.27 to 0.70, all P < 0.05). Consistent with the poorer quality of the δ13C chronologies compared with those from ring widths, tree-ring δ13C was also less strongly correlated with rainfall and rarely significant (P = 0.05). The weaker δ13C correlations may be due to a strong water conservation strategy by Callitris. Our analysis of the whole ring rather than latewood and low sampling effort may also have dampened the δ13C response. However, combining the ring width and δ13C chronologies using Principal Components Analysis did not enhance the extraction of a climatic signal. While the variance explained by the first principal component (PC) was high for all three species (76 to 87%), correlations between the first PC and rainfall were not stronger than for ring widths alone. Tree-ring δ13C, in conjunction with δ18O in particular, may nevertheless provide insight into physiological responses of Callitris to climate variation. However, dendroclimatic studies using Callitris to develop past rainfall records should focus on developing chronologies from ring widths. Further effort to find sites with old trees (250 years or more) should be undertaken and are likely to provide much needed information on past rainfall in Australia.

Tree growth across the Nepal Himalaya during the last four centuries

2017 ◽  
Vol 41 (4) ◽  
pp. 478-495 ◽  
Author(s):  
UK Thapa ◽  
S St. George ◽  
DK Kharal ◽  
NP Gaire
Keyword(s):  
Tree Ring ◽  
Tree Growth ◽  
Environmental Changes ◽  
Ring Width ◽  
High Elevation ◽  
Forest Growth ◽  
Tree Ring Width ◽  
Early 19Th Century ◽  
Tree Ring Data ◽  
Instrumental Records

The climate of Nepal has changed rapidly over the recent decades, but most instrumental records of weather and hydrology only extend back to the 1980s. Tree rings can provide a longer perspective on recent environmental changes, and since the early 2000s, a new round of field initiatives by international researchers and Nepali scientists have more than doubled the size of the country’s tree-ring network. In this paper, we present a comprehensive analysis of the current tree-ring width network for Nepal, and use this network to estimate changes in forest growth nation-wide during the last four centuries. Ring-width chronologies in Nepal have been developed from 11 tree species, and half of the records span at least 290 years. The Nepal tree-ring width network provides a robust estimate of annual forest growth over roughly the last four centuries, but prior to this point, our mean ring-width composite fluctuates wildly due to low sample replication. Over the last four centuries, two major events are prominent in the all-Nepal composite: (i) a prolonged and widespread growth suppression during the early 1800s; and (ii) heightened growth during the most recent decade. The early 19th century decline in tree growth coincides with two major Indonesian eruptions, and suggests that short-term disturbances related to climate extremes can exert a lasting influence on the vigor of Nepal’s forests. Growth increases since AD 2000 are mainly apparent in high-elevation fir, which may be a consequence of the observed trend towards warmer temperatures, particularly during winter. This synthesis effort should be useful to establish baselines for tree-ring data in Nepal and provide a broader context to evaluate the sensitivity or behavior of this proxy in the central Himalayas.

Spatial and temporal stability of the climatic signal in northern Fennoscandian pine tree-ring width and maximum density

Boreas ◽  
2009 ◽  
Vol 38 (1) ◽  
pp. 1-12 ◽  
Author(s):  
MERVI TUOVINEN ◽  
DANNY McCARROLL ◽  
HÅKAN GRUDD ◽  
RISTO JALKANEN ◽  
SIETSE LOS
Keyword(s):  
Tree Ring ◽  
Temporal Stability ◽  
Ring Width ◽  
Maximum Density ◽  
Tree Ring Width ◽  
Pine Tree ◽  
Climatic Signal

Weakening climatic signal since mid-20th century in European larch tree-ring chronologies at different altitudes from the Adamello-Presanella Massif (Italian Alps)

2012 ◽  
Vol 77 (3) ◽  
pp. 344-354 ◽  
Author(s):  
Anna Coppola ◽  
Giovanni Leonelli ◽  
Maria Cristina Salvatore ◽  
Manuela Pelfini ◽  
Carlo Baroni
Keyword(s):  
Tree Ring ◽  
Function Analysis ◽  
Ring Width ◽  
Negative Influence ◽  
Summer Temperature ◽  
Central Alps ◽  
European Larch ◽  
Climatic Signal ◽  
Temperature Signal ◽  
Over Time

Tree rings from temperature-limited environments are highly sensitive climate proxies, widely used to reconstruct past climate parameters for periods prior to the availability of instrumental data and to analyse the effect of recent global warming on tree growth. An analysis of the climatic signal in five high-elevation tree-ring width chronologies of European larch (Larix decidua Mill.) from the tops of five different glacial valleys in the Italian Central Alps revealed that they contain a strong summer-temperature signal and that tree-ring growth is especially influenced by June temperatures. However, a moving correlation function analysis revealed a recent loss of the June temperature signal in the tree-ring chronologies. This signal reduction primarily involves the two lowest-altitude chronologies. It is probable that the observed increasing importance of late-summer temperature for tree-ring growth over the past 50 yr is an effect of the lengthening growing season and of the variations in the climate/tree-ring relationship over time. All the chronologies considered, especially those at the highest altitudes, show an increasing negative influence of June precipitation on tree-ring growth. The climatic signal recorded in tree-ring chronologies from the Italian Central Alps varies over time and is also differentially influenced by climatic parameters according to site elevation.

A lonely dot on the map: Exploring the climate signal in tree-ring density and stable isotopes of clanwilliam cedar, South Africa

2021 ◽  
Vol 69 ◽  
pp. 125879
Author(s):  
Tom De Mil ◽  
Matthew Meko ◽  
Soumaya Belmecheri ◽  
Edmund February ◽  
Matthew Therrell ◽  
...  
Keyword(s):  
South Africa ◽  
Stable Isotopes ◽  
Tree Ring ◽  
Climate Signal ◽  
Ring Density

scholarly journals Experiments based on blue intensity for reconstructing North Pacific temperatures along the Gulf of Alaska

2017 ◽  
Vol 13 (8) ◽  
pp. 1007-1022 ◽  
Author(s):  
Rob Wilson ◽  
Rosanne D'Arrigo ◽  
Laia Andreu-Hayles ◽  
Rose Oelkers ◽  
Greg Wiles ◽  
...  
Keyword(s):  
Tree Ring ◽  
North Pacific ◽  
Ring Width ◽  
Gulf Of Alaska ◽  
Climate Response ◽  
Cool Period ◽  
Climate Signal ◽  
Latewood Density ◽  
Blue Intensity

Abstract. Ring-width (RW) records from the Gulf of Alaska (GOA) have yielded a valuable long-term perspective for North Pacific changes on decadal to longer timescales in prior studies but contain a broad winter to late summer seasonal climate response. Similar to the highly climate-sensitive maximum latewood density (MXD) proxy, the blue intensity (BI) parameter has recently been shown to correlate well with year-to-year warm-season temperatures for a number of sites at northern latitudes. Since BI records are much less labour intensive and expensive to generate than MXD, such data hold great potential value for future tree-ring studies in the GOA and other regions in mid- to high latitudes. Here we explore the potential for improving tree-ring-based reconstructions using combinations of RW- and BI-related parameters (latewood BI and delta BI) from an experimental subset of samples at eight mountain hemlock (Tsuga mertensiana) sites along the GOA. This is the first study for the hemlock genus using BI data. We find that using either inverted latewood BI (LWBinv) or delta BI (DB) can improve the amount of explained temperature variance by > 10 % compared to RW alone, although the optimal target season shrinks to June–September, which may have implications for studying ocean–atmosphere variability in the region. One challenge in building these BI records is that resin extraction did not remove colour differences between the heartwood and sapwood; thus, long term trend biases, expressed as relatively warm temperatures in the 18th century, were noted when using the LWBinv data. Using DB appeared to overcome these trend biases, resulting in a reconstruction expressing 18th–19th century temperatures ca. 0.5 °C cooler than the 20th–21st centuries. This cool period agrees well with previous dendroclimatic studies and the glacial advance record in the region. Continuing BI measurement in the GOA region must focus on sampling and measuring more trees per site (> 20) and compiling more sites to overcome site-specific factors affecting climate response and using subfossil material to extend the record. Although LWBinv captures the inter-annual climate signal more strongly than DB, DB appears to better capture long-term secular trends that agree with other proxy archives in the region. Great care is needed, however, when implementing different detrending options and more experimentation is necessary to assess the utility of DB for different conifer species around the Northern Hemisphere.

Separating the climatic signal from tree-ring width and maximum latewood density records

Trees ◽  
2006 ◽  
Vol 21 (1) ◽  
pp. 37-44 ◽  
Author(s):  
Alexander V. Kirdyanov ◽  
Eugene A. Vaganov ◽  
Malcolm K. Hughes
Keyword(s):  
Tree Ring ◽  
Ring Width ◽  
Tree Ring Width ◽  
Maximum Latewood Density ◽  
Climatic Signal ◽  
Latewood Density

scholarly journals A dendroecological assessment of whitebark pine in the Sawtooth–Salmon River region, Idaho

1996 ◽  
Vol 26 (12) ◽  
pp. 2123-2133 ◽  
Author(s):  
Dana L. Perkins ◽  
Thomas W. Swetnam
Keyword(s):  
Tree Ring ◽  
Mountain Pine Beetle ◽  
Ring Width ◽  
High Elevation ◽  
Whitebark Pine ◽  
Spring Precipitation ◽  
Salmon River ◽  
Mountain Pine ◽  
River Region ◽  
Pine Beetle

Whitebark pine (Pinusalbicaulis Engelm.) tree-ring chronologies of 700 to greater than 1000 years in length were developed for four sites in the Sawtooth–Salmon River region, central Idaho. These ring-width chronologies were used to (i) assess the dendrochronological characteristics of this species, (ii) detect annual mortality dates of whitebark pine attributed to a widespread mountain pine beetle (Dendroctonusponderosae Hopkins (Coleoptera: Scolytidae)) epidemic during the 1909–1940 period, and (iii) establish the response of whitebark pine ring-width growth to climate variables. Cross-dating of whitebark pine tree-ring patterns was verified. Ring-width indices had low mean sensitivity (0.123–0.174), typical of high-elevation conifers in western North America, and variable first-order autocorrelation (0.206–0.551). Mountain pine beetle caused mortality of dominant whitebark pine peaked in 1930 on all four sites. Response functions and correlation analyses with state divisional weather records indicate that above-average radial growth is positively correlated with winter and spring precipitation and inversely correlated with May temperature. These correlations appear to be a response to seasonal snowpack. Whitebark pine is a promising species for dendroclimatic studies.

scholarly journals Exploring Growth Variability and Crown Vitality of Sessile Oak (Quercus Petraea) in the Czech Republic

2015 ◽  
Vol 42 (1) ◽  
Author(s):  
Michal Rybníček ◽  
Petr Čermák ◽  
Tomáš Žid ◽  
Tomáš Kolář ◽  
Miroslav Trnka ◽  
...  
Keyword(s):  
Management Strategies ◽  
Ring Width ◽  
Quercus Petraea ◽  
Future Climate Change ◽  
Summer Drought ◽  
Crown Condition ◽  
Spring Precipitation ◽  
Climatic Effects ◽  
Growth Variability ◽  
Width Measurements

Abstract Unraveling climatic effects on growth of oak - Europe’s most ecologically and economically important forest species - has been the subject of many recent studies; however, more insight based on field data is necessary to better understand the relationship between climate and tree growth and to adapt forest management strategies to future climate change. In this report, we explore the influence of temperature, precipitation and drought variability on the productivity and vitality of oak stands in the Czech Highlands. We collected 180 cores from mature oaks (Quercus petraea) at four forest stands in the Czech Drahany Highlands. Standard dendromethods were used for sample preparation, ring width measurements, cross-dating, chronology development, and the assessment of growth-climate response patterns. Crown vitality was also evaluated, using the modified ICP Forests methodology. Late spring precipitation totals between May and June as well as the mean July temperature for the year of ring formation were found to be the most important factors for oak growth, whereas crown condition was significantly affected by spring and summer drought. This study is rep-resentative for similar bio-ecological habitats across Central Europe and can serve as a dendroclima-tological blueprint for earlier periods for which detailed meteorological information is missing

Preliminary reconstructions of spring precipitation in southwestern Turkey from tree-ring width

2003 ◽  
Vol 23 (2) ◽  
pp. 157-171 ◽  
Author(s):  
Ramzi Touchan ◽  
Gregg M. Garfin ◽  
David M. Meko ◽  
Gary Funkhouser ◽  
Nesat Erkan ◽  
...  
Keyword(s):  
Tree Ring ◽  
Ring Width ◽  
Tree Ring Width ◽  
Spring Precipitation
Sign in / Sign up

Export Citation Format

Share Document