Coupled Pacific Rim megadroughts contributed to the fall of the MingDynasty’s capital in 1644 CE

Historical documents provide evidence for regional droughts preceding the political turmoil and fall of Beijing in 1644 CE,when more than 20 million people died in northern China during the late Ming famine period.However,the role climate and environmental changes may have played in this pivotal event in Chinese history remains unclear.Here,we provide tree-ring evidence of persistent megadroughts from1576 to 1593 CE and from 1628 to 1644 CE in northern China,which coincided with exceptionally cold summers just before the fall of Beijing.Our analysis reveals that these regional hydroclimatic extremes are part of a series of megadroughts along the Pacific Rim,which not only impacted the ecology and society of monsoonal northern China,but likely also exacerbated external geopolitical and economic pressures.This finding is corroborated by last millennium reanalysis data and numerical climate model simulations revealing internally driven Pacific sea surface temperature variations and the predominance of decadal scale La Ni?a-like conditions to be responsible for precipitation decreases over northern China,as well as extensive monsoon regions in the Americas.These teleconnection patterns provide a mechanistic explanation for reoccurring drought spells during the late Ming Dynasty and the environmental framework fostering the fall of Beijing in 1644 CE,and the subsequent demise of the Ming Dynasty.

Unmanned aerial vehicles(UAV)for assessment of qualitative classification of Norway spruce in temperate forest stands

The study investigates the potential of UAV-based remote sensing technique for monitoring of Norway spruce health condition in the affected forest areas.The objectives are:(1)to test the applicability of UAV visible an near-infrared(VNIR)and geometrical data based on Z values of point dense cloud(PDC)raster to separate forest species and dead trees in the study area;(2)to explore the relationship between UAV VNIR data and individual spruce health indicators from field sampling;and(3)to explore the possibility of the qualitative classification of spruce health indicators.Analysis based on NDVI and PDC raster was successfully applied for separation of spruce and silver fir,and for identification of dead tree category.Separation between common beech and fir was distinguished by the object-oriented image analysis.NDVI was able to identify the presence of key indicators of spruce health,such as mechanical damage on stems and stem resin exudation linked to honey fungus infestation,while stem damage by peeling was identified at the significance margin.The results contributed to improving separation of coniferous(spruce and fir)tree species based on VNIR and PDC raster UAV data,and newly demonstrated the potential of NDVI for qualitative classification of spruce trees.The proposed methodology can be applicable for monitoring of spruce health condition in the local forest sites.

Ecosystem management in transition in Central and Eastern Europe: the need for a vision

It is well established that in current human-dominated world,environmental change is closely coupled with socio-economic factors,and this is reflected in conceptual frameworks of important policies(Díaz et al.2015).Humans are adversely affecting biodiversity and climate change on a planetary scale(Rockström et al.2009).Anthropogenic transformation of ecosystems has been driven by rapid social and economic changes,manifested by direct drivers such as land use change and climate change(Nelson et al.2006).Central and Eastern Europe(CEE)has been a rap-idly transitioning region in terms of economic growth and political changes.Following the collapse of former Eastern Bloc and revolutions in several CEE countries after 1989,CEE countries have been undergoing political and economic transformation toward democracy and free market.Continuous accession to the European Union also brought in changes of political environment and ecosystem management possibilities and outcomes.Profound socioeconomic changes have influenced environmental condition and ecosystem management in this region,with changing pres-sures on biodiversity and ecosystem services.Environmental changes in Central and Eastern Europe have been closely linked especially to agricultural policy.For example,inorganic fertilizer use in several CEE countries dropped in a single year to 25%of its former level after the collapse of socialism.This,in turn,had an enormous impact on farmland biodiversity(Stoate et al.2009).