Changes of the Flowering Time of Trees in Spring by Climate Change in Seoul, South Korea

Flowering onset has attracted much attention in ecological research as an important indicator of climate change.Generally,warmer temperatures advance flowering onset.The effect of climate warming on flowering onset is more pronounced in spring because the difference between atmospheric and water temperatures creates more rapid convection than in other seasons.We analyzed the correlation between 73 species of spring woody plants in Hongneung Arboretum in Seoul,South Korea and the spring minimum temperature and average precipitation over the past 50 years(1968–2018).The spring minimum temperature and average precipitation have increased over the past 50 years,resulting in the advance of the first flowing date(FFD)in all 73 species by 8.5 days on average.A comparison of FFD changes over time by dividing the survey period into three time periods confirmed the advance of the FFD in 50 species(68%of investigated species)by 11.1 days on average in both Period 2(1999–2008)and Period 3(2009–2018)relative to Period 1(1968–1975).Additionally,a delay of the FFD by 3.2 days on average was observed in 8 species.The FFD of Lonicera chrysantha(Caprifoliaceae)advanced by over 40 days and was highly correlated with the increased spring minimum temperature.Analysis of the sensitivity of plant responses to climate change revealed that a temperature rise of 1℃ was associated with an FFD advance of 1.2 days in all species.The species that was most sensitive to temperature change was Spiraea pubescens for.leiocarpa(Rosaceae),whose FFD advanced by 4.7 days per 1℃ temperature rise.Each increase in precipitation by 1 mm was found to result in a 0.1-day advance of the FFD of all species.Prunus tomentosa(Rosa-ceae)was the most sensitive species,that advanced by 2.6 days for each 1 mm increase in precipitation.Thus,for all species,the FFD was more sensitive to the change in temperature than in precipitation.Assuming that the current greenhouse gas(GHGs)emission levels or atmospheric CO_(2) concentration is maintained,Seoul’s spring minimum temperature is projected to rise by 2.7℃ over the next 50 years.Accordingly,considering only the global temperature change,the mean FFD of the study’s 73 species is projected to advance by an additional 3.4 days.

Empirical assessment of adaptation to climate change impacts of mountain households:development and application of an Adaptation Capability Index

The present study proposes an index to assess the potential for adaptation to climate change for households in the mountainous regions. The index provides a realistic approach to recognize social and natural factors which contribute to successful adaptation and addresses several household functions, such as social networking, livelihood strategy, adjustment strategies, resource availability and accessibility. The proposed Adaptation Capability Index （ACI） is analytically defined, mathematically formulated and field tested on mountainous households in urban and semi-urban regions of the Uttarakhand Himalaya in India. To gather data on the topic relevant to the ACI, a household scale questionnaire was developed and administered to 12o heads of households through face-to-face interviews. The results highlight higher adaptive capability of urban households and low adaptation capacity of rural households due to poor farm productivity, low accessibility and availability of resources and technological input. Future programs and policies must include and implement regulations to remedy attributive factors responsible for higher adaptation. This paper may be applicable to other mountainous regions and may provide insights for effective adaptation strategies to climate change.

Biomass production,nutrient cycling and distribution in age-sequence Chinese fir(Cunninghamia lanceolate)plantations in subtropical China

Biomass production and nutrient （N, P, K, Ca and Mg） accumulation, distribution and cycling were quantified in young, mature and over-mature （10-, 22-, and 34-year old） Chinese fir [Cunninghamia lanceolate （Lamb.） Hook] plantations in southern China. Total stand biomass of young, mature and over-mature stands was 38, 104 and 138 t ha-1 respectively. Biomass production increased significantly with age. Stem wood represented the highest percentage of stand biomass, accounting for 41, 55 and 63 % in the young, mature and over-mature plan- tations respectively. Nutrients concentration was highest in live needles and branches, and lowest in stem wood. The plantations accumulated more N, followed by K, Ca, Mg, and P. Nutrient return amount, nutrient utilization effi- ciency, nutrient turnover time, the ratio of nutrient return and uptake increased with stand age, which implies that young Chinese fir deplete soil nutrients to maintain growth, and efficiently utilize nutrients to decrease dependence on soil nutrients as they age. Harvesting young Chinese fir plantations would therefore lead to high nutrient loss, but prolonging the rotation length could improve soil recovery, and help sustain productivity in the long-term. Improved nutrient return through litterfall as stands get older may also be beneficial to nutrient pool recovery.

Litterfall production and nutrient return in different-aged Chinese fir(Cunninghamia lanceolata) plantations in South China

The amounts of litter produced and nutrients returned play a fundamental role in the productivity and biogeochemical and nutrient cycling of forest ecosystems.We monitored annual litterfall production, nutrient return,and monthly dynamics over a one-year period in Chinese fir plantations aged 10, 22, and 34 years. Our objective was to quantify litterfall and nutrient return over a complete harvest rotation of Chinese fir. Annual litterfall production increased with stand age and was recorded as（3,294.6 ± 360.4）,（3,733.9 ± 211.2）, and（4,876.1 ± 212.8） kg ha-1a-1in stands aged 10, 22 and 34 years, respectively. Total litter production was significantly greater in the stand aged34 years than in the stand aged 10 years（p ／ 0.05）. With the exception of miscellaneous components, needle litterfall constituted the highest proportion（27.5–43.6 %）, followed by branches/twigs（9.5–16.6 %）. In all three plantations,annual total nutrient return to soil was in the order of C（1,119.95–2,709.05 kg ha-1a-1） [ N（39.32–62.04 kg ha-1a-1） [ K（15.95–22.44 kg ha-1a-1） [ P（1.30–1.63 kg ha-1a-1）. C, N, K and P input to soil was significantly lower in the 10-year-old stand in comparison to the 22- and34-year-old stands（p ／ 0.05）. Litterfall production and nutrient return（C, N and K） followed similar patterns, and C and N input to soil was significantly related to litterfall production（needle, branch and total litterfall）. C, N, P and K input to soil and total litterfall production were mainly driven by needle litterfall.

Impacts of Increasing Temperature on the Future Incidence of West Nile Neuroinvasive Disease in the United States

Multiple studies have identified links between climate and West Nile virus disease since the virus arrived in North America. Here we sought to extend these results by developing a Health Impact Function (HIF) to generate county-level estimates of the expected annual number of West Nile neuroinvasive disease (WNND) cases based on the county’s historical WNND incidence, annual average temperature, and population size. To better understand the potential impact of projected temperature change on WNND risk, we used the HIF to project the change in expected annual number of WNND cases attributable to changing temperatures by 2050 and by 2090 using data from five global climate models under two representative concentration pathways (RCP4.5 and RCP8.5). To estimate the costs of anticipated changes, as well as to enable comparisons with other public health impacts, projected WNND cases were allocated to nonfatal and fatal outcomes, then monetized using a cost-of-illness estimate and the U.S. Environmental Protection Agency’s value of a statistical life, respectively. We found that projected future temperature and population changes could increase the expected annual number of WNND cases to ≈2000 - 2200 cases by 2050 and to ≈2700 - 4300 cases by 2090, from a baseline of 970 cases. Holding population constant at future levels while varying temperature from a 1995 baseline, we estimated projected temperature change alone is responsible for ≈590 and ≈960 incremental WNND cases in 2050 and 2090 (respectively) under the RCP4.5 scenario, and ≈820 and ≈2500 cases in 2050 and 2090 (respectively) for the RCP8.5 scenario, with substantial regional variation. The monetized impact of these temperature-attributable incremental cases is estimated at $0.5 billion in 2050 and $1.0 billion in 2090 under the RCP4.5 scenario, and $0.7 billion in 2050 and $2.6 billion in 2090 under the RCP8.5 scenario (undiscounted 2015 U.S. dollars).

Seasonal Variation of Potential Source Locations of Atmospheric Particulates over the Indo-Gangetic Plain of India

Ambient particulate matter (PM2.5 and PM10) concentrations were measured during two different seasons (summer and winter) at three different locations of Gurugram which is located in the Indo-Gangetic plain of India. The ambient concentrations of both PM2.5 and PM10 were higher during winter season (PM2.5: 261 μg·m-3;PM10: 440 μg·m-3) when compared to summer period (PM2.5: 114 μg·m-3;PM10: 202 μg·m-3). Potential Source Contribution Function (PSCF) analysis suggests significant seasonal variation in potential contributing locations of ambient PM2.5 over the study area. The PSCF analysis suggests that cross country transport of PM2.5 from Pakistan and Afghanistan significantly attributed to higher concentrations of PM2.5 at the study locations;whereas, PM2.5 emitted from locations in the south-western direction of the study sites attributed to the ambient PM2.5 concentrations at the study site during summer seasons. Further study is required to measure percentage contribution from different sectors and locations to the ambient particulate concentrations at the study site to develop sector specific mitigation plan.

Investigating energy policies to boost grid-connected rooftop solar PV in Sudan

Grid-connected rooftop solar photovoltaic(PV)systems can reduce the energy demand from the grid and significantly increase the power available to it.However,rooftop solar PV has not yet been widely adopted in many sub-Saharan African countries,such as Sudan,although they are endowed with high solar radiation and in dire need of additional power.This paper investigates risks and policies to increase grid-connected rooftop solar PV adoption in Sudan.A simplified United Nations Development Program Derisking Renewable Energy Investment framework is adopted to investigate this over three stages.For Stage 1,a list of risks and barriers was produced based on a literature review of solar PV studies in Sudan and interviews with nine stakeholders.Affordability was the risk most often mentioned(eight times from nine interviewees),followed by concerns about poor utility grid infrastructure.For Stage 2,policy de-risking instruments and financial de-risking instruments were listed to overcome the barriers.These include the intro-duction of net metering,the use of a third-party organization to monitor policy implementation,upgrade of the grid infrastructure,public awareness campaigns and energy-saving schemes.For Stage 3,the levelized cost of electricity was estimated for a typical 2-kW rooftop PV system without policies(0.11$/kWh)and with a net-metering policy(0.07$/kWh).

Recent advances in assessment of soil erosion vulnerability in a watershed

Soil erosion is one of the most critical hazards adversely affecting both environment and economy.Assessment of the annual soil erosion rate provides information on soil erosion risk zones indicating the areas with high,severe and low risks.Modelling and prediction of soil erosion has a long history of more than seven decades.It becomes imperative to be familiar with the quantum of studies conducted and methods employed across the world to assess vulnerability of ecosystems to soil erosion to plan strategies for their conservation.There are several methods based on various factors like land use,soil quality,topography etc.available to assess the susceptibility of a region to soil loss.With time the gap in understanding of such models and their use around the world has increased.Numerous models for assessing soil erosion exist but there is a lack of knowledge on spatial distribution of the methods being used.Academic papers related to assessment of soil erosion vulnerability published during the past three decades(1991—2019)were reviewed.Total 160 studies were reviewed to understand advances in the methods used to assess soil erosion vulnerability worldwide,identification of the most popular methods and proportion of studies conducted in the fragile region of Himalayas.The results show that 18 different methods have mainly been used to assess soil erosion risk in different regions.These methods include statistical,physical,process based and empirical models.The use of few physical methods like ANSWERS and SHE has decreased with time while that of physical and process methods like RUSLE,SWAT,WEPP and PESERA has increased with time.The review highlighted that various models being used worldwide are based on their suitability to the region.It also brings to attention that few models like PESERA,EUROSEM and WEPP are mostly being used concentrated in a particular region.Models like PESERA and EPM are mostly used in European region and may be encouraged to estimate soil erosion in Himalayan region.The review also highlights lack of studies with inclusion of water quality as an important parameter while assessing soil erosion vulnerability in the region.The review suggests that in case of lack of data,various statistical methods like PCA,CF,FUZZY etc can be preferred for qualitative assessment over quantitative assessment Considering availability of accurate input,researchers need to attempt more methods and perform comparative studies to attain accurate results for assessing soil erosion vulnerability leading to strategizing soil conservation in fragile regions.