1.        Patterson, T., Maxwell, R. S.,Harley, G. L., Oliver, J. S., Speer, J. H., Collins, S., ... & Russell, C.(2016). Climate—Growth Relationships of Pinus rigida (Mill.) at the Species'Northern Range Limit, Acadia National Park, ME. Northeastern Naturalist, 23(4),490-500.

This study examined climate—tree growthrelationships of a G2 globally rare Pinus rigida (Pitch Pine) barren located atthe species' northern range limit in Acadia National Park, ME. Our tree-ringchronologies spanned the period 1804–2014 CE and included 50 dated tree-ringseries from 33 trees. We found significant (P < 0.05) positive correlationsin all chronologies between each year's tree growth and previous Octoberthrough April temperature, as well as with August precipitation. Additionally,we found negative correlations between our chronologies and previous Julyprecipitation. Moving interval correlation analysis showed temporal instabilityof all climate—growth relationships except for April temperature and Augustprecipitation for the total width and latewood chronologies. Our resultscorroborate previous findings that suggest tree species at their northern rangelimit respond positively to winter temperature. We posit warmer wintertemperatures and enhanced late-summer precipitation indicate a maritimeinfluence that positively influenced radial growth at our site.

http://www.bioone.org/doi/pdf/10.1656/045.023.0406

2.        Reinmann, A. B., & Hutyra,L. R. (2016). Edge effects enhance carbon uptake and its vulnerability toclimate change in temperate broadleaf forests. Proceedings of the NationalAcademy of Sciences, 201612369.

Forest fragmentation is a ubiquitous,ongoing global phenomenon with profound impacts on the growing conditions ofthe world’s remaining forest. The temperate broadleaf forest makes a largecontribution to the global terrestrial carbon sink but is also the most heavilyfragmented forest biome in the world. We use field measurements and geospatialanalyses to characterize carbon dynamics in temperate broadleaf forestfragments. We show that forest growth and biomass increase by 89 ± 17% and 64 ±12%, respectively, from the forest interior to edge, but ecosystem edgeenhancements are not currently captured by models or approaches to quantifyingregional C balance. To the extent that the findings from our research representthe forest of southern New England in the United States, we provide apreliminary estimate that edge growth enhancement could increase estimates ofthe region’s carbon uptake and storage by 13 ± 3% and 10 ± 1%, respectively.However, we also find that forest growth near the edge declines three timesfaster than that in the interior in response to heat stress during the growingseason. Using climate projections, we show that future heat stress could reducethe forest edge growth enhancement by one-third by the end of the century.These findings contrast studies of edge effects in the world’s other majorforest biomes and indicate that the strength of the temperate broadleaf forestcarbon sink and its capacity to mitigate anthropogenic carbon emissions may bestronger, but also more sensitive to climate change than previous estimatessuggest.

http://www.pnas.org/content/early/2016/12/13/1612369114.full.pdf

3.        Yajun, W. A. N. G., &Mingqi, L. I. (2016). Research progress of dry-wet climate reconstruction bytree ring in China. PROGRESS IN GEOGRAPHY, 35(11), 1397-1410.

With accurate dating, high resolution, andhigh continuity, tree-ring data become one of the important sources forreconstructing the climate change. The sampling sites distribute widely, manytree species were selected, and the chronologies are very long for studying therelationship of the tree ring and dry-wet changes in China. Significantprogress has been made in analyzing the response of tree radial growth to dry-wetchanges and reconstructing historical dry-wet climate change based on variousresearch proxies, such as tree-ring width, density, and stable isotopes. Ingeneral, moisture condition, especially in the spring and autumn and annualhumidity are the important influencing factors of tree-radial growth in lowaltitudes of arid and semi-arid areas. For trees in the upper limit of forestvegetation, relatively cold-wet areas, and the subtropical climate zone inChina, the correlation between tree growth and precipitation was weak. Dry-wetclimate reconstruction based on tree-ring data in China is plentiful. Up tonow, many precipitation series of more than 1000a or even over 2000a werereconstructed in a large number of regions. The longest tree-ring chronology is4500a, and the longest precipitation reconstruction sequence is 3500a. Thebrief summary of selected tree-ring results in this article will providereferences and help for tree-ring sampling and dry-wet climate reconstruction.

http://www.progressingeography.com/EN/abstract/abstract38778.shtml#1

4.        Zhang, P., Ionita, M., Lohmann,G., Chen, D., & Linderholm, H. W. (2016). Can tree-ring density datareflect summer temperature extremes and associated circulation patterns overFennoscandia?. Climate Dynamics, 1-16.

Tree-ring maximum latewood density (MXD)records from Fennoscandia have been widely used to infer regional- andhemispheric-scale mean temperature variability. Here, we explore if MXD recordscan also be used to infer past variability of summer temperature extremesacross Fennoscandia. The first principal component (PC1) based on 34 MXDchronologies in Fennoscandia explains 50% of the total variance in the observedwarm-day extremes over the period 1901–1978. Variations in both observed summerwarm-day extremes and PC1 are influenced by the frequency of anomalousanticyclonic pattern over the region, summer sea surface temperatures over theBaltic, North and Norwegian Seas, and the strength of the westerly zonal wind at200 hPa across Fennoscandia. Both time series are associated with nearlyidentical atmospheric circulation and SST patterns according to composite mapanalysis. In a longer context, the first PC based on 3 millennium-long MXDchronologies in central and northern Fennoscandia explains 83% of the totalvariance of PC1 from the 34 MXD chronologies over the period 1901–1978, 48% ofthe total variance of the summer warm-day extreme variability over the period1901–2006, and 36% of the total variance in the frequency of a summeranticyclonic pattern centered over eastern-central Fennoscandia in the period1948–2006. The frequency of summer warm-day extremes in Fennoscandia is likelylinked to a meridional shift of the northern mid-latitude jet stream. This studyshows that the MXD network can be used to infer the variability of past summerwarm-day extremes and the frequency of the associated summer anticycloniccirculation pattern over Fennoscandia.

http://link.springer.com/content/pdf/10.1007%2Fs00382-016-3452-5.pdf