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This special issue, entitled "Paleolimnology and Paleoecology in a Rapidly Changing Asia," was initiated during the third China Workshop on Lake Paleoecology that was held in Kunming, China, in December, 2019. Here, we summarize some of the key findings from the 10 papers that are included in this issue. The papers present sediment surveys of lakes from different parts of East Asia, and studies that spanned a variety of timescales, through multi-proxy analyses of modern samples, short cores and Holocene records. Overall, this special issue provides an up-to-date research snapshot in the fields of paleolimnology and paleoecology from rapidly changing regions of Asia, with a focus on the sediment signals of lake development, ecological shifts and anthropogenic forcing in the context of continuing climatic and societal changes. [ABSTRACT FROM AUTHOR]

The paper presents results of long-term (for seven years) monitoring and analysis of the formation of rainwater acidity in Primorsky Krai, southern Russian Far East. These results reveal the variability in the concentrations of both of total dissolved solids (TDS) and individual elements. Two groups of years were distinguished in the general dataset during which the character of the atmospheric circulation played an important role in the ionic balance of the rainwater. The study area was shown to be characterized by predominantly acidic precipitation, with the pH of the water rarely exceeding 5.3 even at low concentrations of strong acid anions. In order to identify the factors that form the acidity of rainwater, the paper proposes to rank the initial dataset according to the value of fractional acidity. In the course of this separation, data blocks with a high and low degree of neutralization of the acid potential are distinguished. Within each data block, the relationships between the pH value and the concentrations of the major ions are defined. During the analysis, it was found that the mechanism of acid rain generation is determined by the mutual influence of natural and human-made sources. It was shown that compounds of dissolved organic carbon (DOC) were involved in both acidification and neutralization of rainwater. The results obtained indicate the predominance of natural rain acidification factors. However, during periods of cyclonic activity, even a slight increase in anthropogenic load leads to an increase in the acidity of atmospheric precipitation to critical values. [ABSTRACT FROM AUTHOR]

The current paper tackles a critical question in climate change literature of whether farmers will be able to fully adapt to monsoonal climate changes owing to technological developments. Making use of the climate, agricultural and social data of Thailand from 1900 to 2015, this paper estimates a technological change instrumental variable by the growth of the normalized rice yield per hectare of land. The estimation shows that 0.98 of the growth in rice yield can be attributed to technological changes while the rest is accounted for by climate, soils and social factors. In the second stage regressions with the technological change indicator, the paper estimates the normalized numbers of the six most important types of live animals in Thailand: goats, chickens, cattle, sheep, pigs and buffaloes. Over the time period studied, the number of each of these live animals has increased vastly, except for buffaloes. The second-stage regressions show that the growth is largely attributable to technological changes, but monsoonal climate variables such as normalized monsoon precipitation ratio and normalized monsoon temperature are not significant factors. The results indicate that the rate of technological changes is overwhelming the rate of climate change on agriculture in Thailand. [ABSTRACT FROM AUTHOR]

Soil moisture (SM) is essential for sustaining services from Earth's critical zone, a thin-living skin spanning from the canopy to groundwater. In the Anthropocene epoch, intensive afforestation has remarkably contributed to global greening and certain service improvements, often at the cost of reduced SM. However, attributing the response of SM in deep soil to such human activities is a great challenge because of the scarcity of long-term observations. Here, we present a 37 y (1985 to 2021) analysis of SM dynamics at two scales across China's monsoon loess critical zone. Site-scale data indicate that land-use conversion from arable cropland to forest/grassland caused an 18% increase in SM deficit over 0 to 18 m depth (P < 0.01). Importantly, this SM deficit intensified over time, despite limited climate change influence. Across the Loess Plateau, SM storage in 0 to 10 m layer exhibited a significant decreasing trend from 1985 to 2021, with a turning point in 1999 when starting afforestation. Compared with SM storage before 1999, the relative contributions of climate change and afforestation to SM decline after 1999 were -8% and 108%, respectively. This emphasizes the pronounced impacts of intensifying land-use conversions as the principal catalyst of SM decline. Such a decline shifts 18% of total area into an at-risk status, mainly in the semiarid region, thereby threatening SM security. To mitigate this risk, future land management policies should acknowledge the crucial role of intensifying land-use conversions and their interplay with climate change. This is imperative to ensure SM security and sustain critical zone services. [ABSTRACT FROM AUTHOR]

This paper describes a new species of fossil wood, Wataria yunnanica Li et Oskolski, from the Dajie Formation of the middle Miocene in southern Yunnan province, China. This species shows the greatest similarity to the modern genus Reevesia Lindl. from the subfamily Helicteroideae of Malvaceae. The fossil specimen is ascribed to the genus Wataria Terada & Suzuki based on its combination of ring-porous wood and the presence of tile cells. It differs from other Wataria species because vessel groups are common in its latewood. This is the first record of Wataria in China. Other species of this genus have been reported from Oligocene and Miocene deposits in Japan, and from Miocene deposits in Korea. The occurrence of ring-porous wood in the Dajie Formation suggests that there may have been a seasonal (probably monsoonal) climate in southern Yunnan during the middle Miocene. [ABSTRACT FROM AUTHOR]

Purpose: To identify the formation of meteopathic reactions in patients with respiratory diseases under the influence of extreme weather changes in Vladivostok. Methods: The short-term meteopathic reaction in patients with respiratory diseases to the impact of "Weather Complex", consisting of nine weather parameters, on the day of patient's examination and on 1 and 2 days before the examination, was assessed. 146 acclimatized residents of Vladivostok (29 patients with chronic bronchitis, 51 patients with controlled asthma, 39 patients with uncontrolled asthma and 27 healthy volunteers) were examined. Pulmonary function (PF) was studied by spirography and by body plethysmography. Results: The adaptive-compensatory response of PF in patients with respiratory diseases to weather decreases depending on the disease severity, resulting in the development of meteodependence. The impact of "Weather Complex" on a human body is primarily reflected in PF, and the reaction of metabolic parameters is manifested with a 1–2 days time lag. Glutathione peroxidase and glutathione reductase, key factors in maintaining oxidative cell balance, play the most important role in the formation of a compensatory response to weather. In the light of the global health implication, recommendations are suggested to adjust the treatment of patients with respiratory pathology in specific conditions of abruptly changeable weather. Conclusions: The maritime monsoon climate creates an additional strain on both respiratory system and systems that ensure the peroxidation balance worsening bronchopulmonary pathology. [ABSTRACT FROM AUTHOR]

The production of pasture in Ethiopia was simulated by means of a dynamic model. Most of the country is characterized by a tropical monsoon climate with mild temperatures and precipitation mainly concentrated in the June-September period (main rainy season). The production model is driven by solar radiation and takes into account limitations due to relocation, maintenance respiration, conversion to final dry matter, temperature, water stress, and nutrients availability. The model also considers the senescence of grassland which strongly limits the nutritional value of grasses for livestock. The simulation for the 1982-2009 period, performed on gridded daily time series of rainfall and maximum and minimum temperature with a resolution of 0.5°, provided results comparable with values reported in literature. Yearly mean yield in Ethiopia ranged between 1.8 metric ton per hectare (t ha-1) (2002) and 2.6 t ha−1 (1989) of dry matter with values above 2.5 t ha-1 attained in 1983, 1985, 1989, and 2008. The Ethiopian territory has been subdivided in 1494 cells and a frequency distribution of the per-cell yearly mean pasture production has been obtained. This distribution ranges from 0 to 7 t ha-1 and it shows a right skewed distribution and a modal class between 1.5-2 t ha-1. Simulation carried out on long time series for this peculiar tropical environment give rise to as lot of results relevant by the agroecological point of view on space variability of pasture production, main limiting factors (solar radiation, precipitation, temperature), and relevant meteo-climatic cycles affecting pasture production (seasonal and inter yearly variability, ENSO). These results are useful to establish an agro-ecological zoning of the Ethiopian territory. [ABSTRACT FROM AUTHOR]

Despite millions of dollars invested in soil and water conservation practices in the (sub) humid Ethiopian highlands and billions of hours of food-for-work farm labor, sediment concentration in rivers is increasing. This paper reports on the research to reverse the current trend. Based on the understanding of the hydrology of highlands, we provide evidence on sources of surface runoff and sediment and on mechanisms that govern the erosion processes and approaches and how they affect soil and water conservation practices. We suggest that priority in landscape interventions should be given to re-vegetation of the degraded areas so as to reduce the sediment concentration contributions originating from these areas. Additionally, efforts should be directed to gully rehabilitation in the saturated bottom landscape that may consist of vegetating shallow gullies and stabilizing head cuts of deeper gullies Finally, rehabilitation efforts should be directed to increase the rain water infiltration in the upland areas through the hard pan layer by connecting the land surface to the original deep flow paths that exist below about 60 cm. It will reduce the direct runoff during the rainy season and increase baseflow during the dry season.

Climate change has had a huge impact on Southwest China, where extreme weather events have taken on an increasing trend. The region lies in the transition zone of three monsoons (East Asian, Indian, and Tibetan Plateau). We analyzed long-term trends of drought and flood disasters using sequential data on China's drought and flood incidence over 500 years (1501-2000), as well as precipitation records from 45 weather stations during 1961-2010. Results show that both types of disaster became more frequent. During 1501-2000, drought frequency rose from 2.12 to 4.15 per century to 9.03 and flood frequency from 2.06 to 5.09 per century to 11.94. For the 10 decades during 1900-2000, droughts exhibited a significant increasing trend ( R = 0.4491), while floods showed a slight increasing trend ( R = 0.0346). For extreme floods and droughts in 1961-2010, precipitation records revealed that most (2/3) areas in the region had increasing drought or flood frequencies. Generally, both frequency and intensity of these weather hazards conspicuously increased in Southwest China during 1501-2000. [ABSTRACT FROM AUTHOR]

* Premise of the study: The paleogeographical origin of the relict North American Sequoia sempervirens is controversial. Fossil records indicate a Neogene origin for its foliage characteristics. Although several fossils from the Miocene sediments in eastern Asia have been considered to have close affinities with the modem S. sempervirens, they lack the typical features of a leafy twig bearing linear as well as scale leaves, and the fertile shoots terminating by a cone. The taxonomic status of these fossils has remained unclear. * Methods: New better-preserved fossils from the upper Miocene of China indicate a new species of Sequoia. This finding not only confirms the former presence of this genus in eastern Asia, but it also confirms the affinity of this Asian form to the modern relict S. sempervirens. * Key results: The principal foliage characteristics of S. sempervirens had already originated by the late Miocene. The eastern Asian records probably imply a Beringian biogeographic track of the ancestor of S. sempervirens in the early Neogene, at a time when the land bridge was not too cool for this thermophilic conifer to spread between Asia and North America. * Conclusions: The climatic context of the new fossil Sequoia in Southeast Yunnan, based on other floristic elements of the fossil assemblage in which it is found, is presumed to be warm and humid. Following the uplift of the Qinghai-Tibet Plateau, this warm, humid climate was replaced by the present monsoonal climate with dry winter and spring. This change may have led to the disappearance of this hygrophilous conifer from eastern Asia. [ABSTRACT FROM AUTHOR]

Pan coefficients have been developed for the Sukhna lake region in Chandigarh, India that has a humid tropical monsoon climate, using the optimisation technique for annual, monthly and seasonal time scales. Evaporation estimated using the Bowen ratio energy budget method has been considered as actual evaporation. Results show that the pan coefficient for the study area varies significantly both by month and season. The month-wise variation is in the range of 0.72–1.40 and the seasonal variation is in the range of 0.81–1.16. Pan coefficients obtained using various existing models such as Cuenca, Snyder, Modified Snyder, Pereira, Orang, FAO-56 and Wahed–Snyder have also been compared with the developed coefficients. Comparative analysis indicates that the pan coefficients obtained using the Snyder model overestimate evaporation significantly, while the rest of the models significantly underestimate evaporation. The study concludes that the developed pan coefficients are observed to estimate the open-water surface evaporation with a fair degree of accuracy for the study area while the pan coefficient value of 0.7 being used by most field organisations in India give high errors. However, since pan coefficients vary spatially due to the variation in the relative significance of various meteorological parameters, the pan coefficients developed in the present study need to be further evaluated for their suitability to other similar climatic regions of India. [ABSTRACT FROM AUTHOR]

Despite increased attention to the need for sustainable agriculture, fertilizer application rates above crop requirements remain common agricultural practices in South Korea, causing eutrophication of freshwater and coastal ecosystems. The aim of this study is to quantify phosphorus (P) inputs, outputs, and retention in a forested-agricultural watershed. The P budget showed that the combined use of chemical fertilizer and organic compost was the largest source of P (97.6% of the total) followed by atmospheric wet deposition (2.1% of the total P), whereas forest export (0.2% of the total) and sewage treatment plants (STPs) (0.1% of the total) were negligible. The P outputs were crop harvesting and hydrologic export to surface water. The P balance showed that P inputs are higher than the P outputs; approximately 87% of the total P input was retained in the soils within the watershed. However, P concentrations in drainage water were still high enough to cause eutrophication of downstream reservoirs. The results provide important details on the proportion of P export and retention in the watershed. This will help efforts to improve water quality and design better management strategies for agricultural nonpoint source pollution. [ABSTRACT FROM AUTHOR]