Responses of boreal conifers to climate fluctuations: indications from tree-ring widths and carbon isotope analyses

1998 ◽  
Vol 28 (4) ◽  
pp. 524-533 ◽  
Author(s):  
J Renée Brooks ◽  
Lawrence B Flanagan ◽  
James R Ehleringer

Spatial distribution and species composition of the boreal forest are expected to change under predicted climate change scenarios. Current research indicates that water limitations control the southern boundary of the central Canadian boreal forest and temperature limitations control the northern boundary. As part of Boreal Ecosystem - Atmosphere Study (BOREAS), we examined this idea by comparing annual variation in tree-ring widths and carbon isotope ratios ( delta 13C) of tree-ring cellulose with annual climatic parameters in the northern and southern boreal forest. Contrary to expectations, climate correlations with ring widths at the northern and southern sites were similar in black spruce (Picea mariana (Mill.) BSP). Annual growth was favored by cooler and wetter conditions. For jack pine (Pinus banksiana Lamb.), increased temperature and spring precipitation favored annual growth at both sites. In the north, annual growth was negatively correlated with winter precipitation. The delta 13C - climate correlations in Pinus banksiana followed current distribution theories. In the south, potential evapotranspiration explained significant annual delta 13C variation, whereas in the north, winter and growing season precipitation influenced annual delta 13C variations. Our data support the concept that moisture limits the southern range of Pinus banksiana and cold soil temperatures limit the northern extent. However, colder, wetter conditions favored growth of Picea mariana throughout its range. These observations strengthen the concept that species respond individually to climate change, not as a cohesive biome.

Forests ◽  
2020 ◽  
Vol 11 (5) ◽  
pp. 525
Author(s):  
Keliang Zhang ◽  
Lanping Sun ◽  
Jun Tao

Analyzing the effects of climate change on forest ecosystems and individual species is of great significance for incorporating management responses to conservation policy development. Euscaphis japonica (Staphyleaceae), a small tree or deciduous shrub, is distributed among the open forests or mountainous valleys of Vietnam, Korea, Japan, and southern China. Meanwhile, it is also used as a medicinal and ornamental plant. Nonetheless, the extents of E. japonica forest have gradually shrunk as a result of deforestation, together with the regional influence of climate change. The present study employed two methods for modeling species distribution, Maxent and Genetic Algorithm for Rule-set Prediction (GARP), to model the potential distribution of this species and the effects of climate change on it. Our results suggest that both models performed favorably, but GARP outperformed Maxent for all performance metrics. The temperate and subtropical regions of eastern China where the species had been recorded was very suitable for E. japonica growth. Temperature and precipitation were two primary environmental factors affecting the distribution of E. japonica. Under climate change scenarios, the range of suitable habitats for E. japonica will expand geographically toward the north. Our findings may be used in several ways such as identifying currently undocumented locations of E. japonica, sites where it may occur in the future, or potential locations where the species could be introduced and so contribute to the conservation and management of this species.


2014 ◽  
Vol 955-959 ◽  
pp. 3777-3782 ◽  
Author(s):  
Xiao Feng Zhao ◽  
Bin Le Lin

We evaluated land suitability for Jatropha cultivation at a global scale under current and future climate scenarios. Areas that are suitable for Jatropha cultivation include southern South America, the west and southeast coasts of Africa, the north of South Asia, and the north and south coasts of Australia. In the predicted climate change scenarios, areas near the equator become less suitable for Jatropha cultivation, and areas further from the equator become more suitable. Our analyses suggest that the rank order of the six climate change scenarios, from the smallest to the largest effects on Jatropha cultivation, was as follows: B1, A1T/B2, A1B, A2, and A1FI.


2008 ◽  
Vol 15 ◽  
pp. 57-60 ◽  
Author(s):  
Peter Rasmussen ◽  
Mikkel Ulfeldt Hede ◽  
Nanna Noe-Nygaard ◽  
Annemarie L. Clarke ◽  
Rolf D. Vinebrooke

The need for accurate predictions of future environmental change under conditions of global warming has led to a great interest in the most pronounced climate change known from the Holocene: an abrupt cooling event around 8200 years before present (present = A.D. 1950), also known as the ‘8.2 ka cooling event’ (ka = kilo-annum = 1000 years). This event has been recorded as a negative δ18O excursion in the central Greenland ice cores (lasting 160 years with the lowest temperature at 8150 B.P.; Johnsen et al. 1992; Dansgaard 1993; Alley et al. 1997; Thomas et al. 2007) and in a variety of other palaeoclimatic archives including lake sediments, ocean cores, speleothems, tree rings, and glacier oscillations from most of the Northern Hemisphere (e.g. Alley & Ágústsdóttir 2005; Rohling & Pälike 2005). In Greenland the maximum cooling was estimated to be 6 ± 2°C (Alley et al. 1997) while in southern Fennoscandia and the Baltic countries pollenbased quantitative temperature reconstructions indicate a maximum annual mean temperature decrease of around 1.5°C (e.g. Seppä et al. 2007). Today there is a general consensus that the primary cause of the cooling event was the final collapse of the Laurentide ice sheet near Hudson Bay and the associated sudden drainage of the proglacial Lake Agassiz into the North Atlantic Ocean around 8400 B.P. (Fig. 1; Barber et al. 1999; Kleiven et al. 2008). This freshwater outflow, estimated to amount to c. 164,000 km3 of water, reduced the strength of the North Atlantic thermohaline circulation and thereby the heat transported to the North Atlantic region, resulting in an atmospheric cooling (Barber et al. 1999; Clark et al. 2001; Teller et al. 2002). The climatic consequences of this meltwater flood are assumed to be a good geological analogue for future climate-change scenarios, as a freshening of the North Atlantic is projected by almost all global-warming models (e.g. Wood et al. 2003; IPCC 2007) and is also currently being registered in the region (Curry et al. 2003). In an ongoing project, the influence of the 8.2 ka cooling event on a Danish terrestrial and lake ecosystem is being investigated using a variety of biological and geochemical proxy data from a sediment core extracted from Højby Sø, north-west Sjælland (Fig. 2). Here we present data on changes in lake hydrology and terrestrial vegetation in response to climate change, inferred from macrofossil data and pollen analysis, respectively.


IAWA Journal ◽  
2020 ◽  
Vol 41 (2) ◽  
pp. 202-218
Author(s):  
Jeong-Wook Seo ◽  
Dieter Eckstein ◽  
Allan Buras ◽  
Jörg Fromm ◽  
Martin Wilmking ◽  
...  

Abstract Although cell-anatomical variables are promising proxies reflecting seasonal as well as annual climate changes, their interdependencies are not yet fully understood. In the present study we assessed the changes in tree-ring width and various wood anatomical traits, including wall thickness, lumen diameter and tracheid diameter in the radial direction in saplings of Pinus sylvestris under six climatic conditions: 5°C warmer alone (ET) or combined with drought in June (ETJ) and in August (ETA) and CO2 enrichment alone (EC, 770 ppm) or combined with drought in June (ECJ) and in August (ECA). The experiments related to temperature conditions using 2-year saplings and CO2 conditions using 3-year saplings were completed in 2009 and 2010 in a greenhouse, respectively. Results showed that tree-ring width and tracheid diameter were not affected by any of the conditions applied, but the lumen diameter was larger and the wall thickness was thinner than those under control conditions. These reactions were verified under ETJ in the warming treatment and under all conditions under CO2 enrichment conditions. Our results indicated that drought counteracted the effects of elevated CO2 concentrations on wood anatomical properties, signifying complex interactions between the two major effects of climate change. Our comparison of wood parameters through experiments highlight the potential effect of climate change — increased drought stress due to higher temperatures and water shortage as well as elevated ambient CO2, on tracheid lumen diameter and wall thickness. Whereas the ring-width and tracheid diameter practically remained unaffected under the above-mentioned conditions.


Author(s):  
Ren-Yan Duan ◽  
Xiao-Quan Kong ◽  
Min-Yi Huang ◽  
Sara Varela ◽  
Xiang Ji

Many studies predict that climate change will cause species movement and turnover, but few studies have considered the effect of climate change on range fragmentation for current species and/or populations. We used MaxEnt to predict suitable habitat, fragmentation and turnover for 134 amphibian species in China under 40 future climate change scenarios spanning four pathways (RCP2.6, RCP4.5, RCP6 and RCP8.5) and two time periods (the 2050s and 2070s). Our results show that climate change will cause a major shift in the spatial patterns of amphibian diversity. Suitable habitats for over 90% of species will be located in the north of the current range, for over 95% of species in higher altitudes, and for over 75% of species in the west of the current range. The distributions of species predicted to move westwards, southwards and to higher altitudes will contract, while the ranges of the species not showing these trends will expand. Amphibians will lose 20% of their original ranges on average; the distribution outside current ranges will increase by 15%. Climate change will likely modify the spatial configuration of climatically suitable areas. Changes in area and fragmentation of climatically suitable patches are related, which means that species may be simultaneously affected by different stressors as a consequence of climate change.


PeerJ ◽  
2016 ◽  
Vol 4 ◽  
pp. e2185 ◽  
Author(s):  
Ren-Yan Duan ◽  
Xiao-Quan Kong ◽  
Min-Yi Huang ◽  
Sara Varela ◽  
Xiang Ji

Many studies predict that climate change will cause species movement and turnover, but few have considered the effect of climate change on range fragmentation for current species and/or populations. We used MaxEnt to predict suitable habitat, fragmentation and turnover for 134 amphibian species in China under 40 future climate change scenarios spanning four pathways (RCP2.6, RCP4.5, RCP6 and RCP8.5) and two time periods (the 2050s and 2070s). Our results show that climate change may cause a major shift in spatial patterns of amphibian diversity. Amphibians in China would lose 20% of their original ranges on average; the distribution outside current ranges would increase by 15%. Suitable habitats for over 90% of species will be located in the north of their current range, for over 95% of species in higher altitudes (from currently 137–4,124 m to 286–4,396 m in the 2050s or 314–4,448 m in the 2070s), and for over 75% of species in the west of their current range. Also, our results predict two different general responses to the climate change: some species contract their ranges while moving westwards, southwards and to higher altitudes, while others expand their ranges. Finally, our analyses indicate that range dynamics and fragmentation are related, which means that the effects of climate change on Chinese amphibians might be two-folded.


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