Vegetative Growth Response Research Articles

Vegetative growth of Biduri (Calotropis Gigantea) on mycorrhiza and azolla application

Climate change is causing many environmental problems that impact human health. Extreme environmental conditions affect the immune of the human body. It is easily exposed to the disease. The community takes various precautions to improve the immune system. One of them is to use medicinal plants as an endurance enhancer because some medicinal plants contain immunomodulators. Biduri (Calotropis Gigantea) is one of the medicinal plants that allegedly serves as an immune stimulator or immunosuppressive antibody production. Biduri has not been cultivated by the community, growing wildly. Research using Azolla and mycorrhizal was conducted as an effort to domesticize Biduri and prepare the source of medicinal raw material. The research aims to study the effect of Azolla and mycorrhiza on the vegetative growth of biduri. The study used 5 levels of Azolla, namely 0, 5, 7.5, 10, and 12.5 tons ha−1, and 4 levels mycorrhizal, namely 0, 5, 10, and 15 tons ha−1. Treatment combinations are arranged based on a Randomized Complete Block Design and repeated 6 times. The vegetative growth including the plant height, number of leaves, number of leaves, leaf width, leaf length was measured at 12 weeks after transplanting. The response of vegetative growth on Azolla and mycorrhizal application showed the same pattern, the application of mycorrhizal has not shown a difference in height or development of biduri leaves, while the application of Azolla 12.5 tons ha−1 increases the height of plants and leaves development significantly compared to without Azolla.

Responses of vegetation growth to climate change over the Tibetan Plateau from 1982 to 2018

The Tibetan Plateau (TP) plays a critical role in Earth’s climate system and is highly sensitive to global warming. However, comprehensive analysis of the interaction between various climatic factors and vegetation growth across the TP is still limited. Using daily normalized difference vegetation index (NDVI) series interpolated from the 16-day satellite measurements and climatic data during 1982–2018, we investigated the spatiotemporal changes in growing season NDVI (NDVIGS) and associated climatic drivers over the TP and analyzed the responses of NDVIGS to climatic drivers for different vegetation types. Our results show that NDVIGS of the TP as a whole exhibits a significant rising trend (0.0011 year−1; P < 0.01) from 1982 to 2018. However, trends in NDVIGS show apparent spatial heterogeneity over the TP with higher growth rates in forests (trend = 0.012 de−1; P < 0.01) and shrubs (trend = 0.009 de−1; P < 0.01) in the east and southeast than in alpine steppe (trend = 0.003 de−1; P < 0.01) and alpine meadow (trend = 0.006 de−1; P < 0.01) in the west and north. Air temperature, precipitation, and VPD serve as the dominant climatic factor affecting the NDVIGS trends in 62%, 19%, and 12% of the TP, respectively. Additionally, climatic factors show differential impacts on NDVIGS among different vegetation types. Air temperature has a predominantly positive correlation with NDVIGS for all vegetation types, while precipitation has a negative impact on plant growth in the eastern humid forest region but a generally positive impact in the other areas. Our results also highlight that the effect of VPD on NDVIGS varies among different vegetation types. These findings contribute to a systematic understanding of the possible mechanisms underlying the responses of vegetation growth to various climatic drivers across the TP.

Vegetation Browning Trends in Spring and Autumn over Xinjiang, China, during the Warming Hiatus

Satellite-derived vegetation records (GIMMS3g-NDVI) report that climate warming promotes vegetation greening trends; however, the climate impacts on vegetation growth during the global warming hiatus period (1998–2012) remain unclear. In this study, we focused on the vegetation change trend in Xinjiang in spring and autumn before and during the recent warming hiatus period, and their climate-driving mechanisms, which have not been examined in previous studies. Based on satellite records, our results indicated that the summer normalized difference vegetation index (NDVI) in Xinjiang experienced a greening trend, while a browning trend existed in spring and autumn during this period. The autumn NDVI browning trend in Xinjiang was larger than that in spring; however, the spring NDVI displayed a higher correlation with climatic factors than did the autumn NDVI. During the warming hiatus, spring climatic factors were the main controlling factors of spring NDVI, and spring vapor pressure deficit (VPD) had the highest positive correlation with spring NDVI, followed by spring temperature. The larger increase in air temperature in spring than in autumn resulted in increased VPD differences in spring and autumn. In autumn, summer climatic factors (e.g., VPD, WS, RH, and precipitation) were significantly correlated with the autumn NDVI during the warming hiatus. However, the autumn temperature was weakly correlated with the autumn NDVI. Our results have significant implications for understanding the response of vegetation growth to recent and future climatic conditions.

Distribution of soil available nutrients and their response to environmental factors based on path analysis model in arid and semi-arid area of northwest China

The study on the distribution of soil available nutrients and their response to the natural environment can provide valuable data and theoretical guidance for supporting human agricultural activities, especially in arid and semi-arid area where the ecological environment is extremely fragile. Based on the soil sampling and survey data set, this study established the path analysis model of SANs (soil available nutrients, including ammonium nitrogen (AN), available phosphorus (AP) and available potassium (AK)) with topography, climate and vegetation in order to explore how environmental factors interact to affect the content of SANs. Then, we combined Pearson correlation analysis and statistical analysis to explore the distribution of SANs under different environmental conditions and the response of vegetation growth to climate changes, in order to further reveal the availability of soil nutrients. The results showed that vegetation was the most important direct factor affecting AN and AP, and AK was the most sensitive to climate changes. The indirect effects of topography and climate on SANs were much greater than their direct effects. Elevation largely predicted the change of climate environment, and the regional climate directly controlled the growth of vegetation. These indirect effects strengthened the connection between topography as well as climate factors and SANs. It is worth noting that the response of vegetation to temperature and precipitation had time lag, which would have a certain impact on the content of SANs response to the environmental changes. This study is of great significance for improved understanding of soil nutrients supply and how ecosystems respond to soil nutrients availability in arid and semi-arid area.

Shifting season of fire and its interaction with fire severity: Impacts on reproductive effort in resprouting plants.

Fire regimes shape plant communities but are shifting with changing climate. More frequent fires of increasing intensity are burning across a broader range of seasons. Despite this, impacts that changes in fire season have on plant populations, or how they interact with other fire regime elements, are still relatively understudied. We asked (a) how does the season of fire affect plant vigor, including vegetative growth and flowering after a fire event, and (b) do different functional resprouting groups respond differently to the effects of season of fire? We sampled a total of 887 plants across 36 sites using a space‐for‐time design to assess resprouting vigor and reproductive output for five plant species. Sites represented either a spring or autumn burn, aged one to three years old. Season of fire had the clearest impacts on flowering in Lambertia formosa with a 152% increase in the number of plants flowering and a 45% increase in number of flowers per plant after autumn compared with spring fires. There were also season × severity interactions for total flowers produced for Leptospermum polygalifolium and L. trinervium with both species producing greater flowering in autumn, but only after lower severity fires. Severity of fire was a more important driver in vegetative growth than fire season. Season of fire impacts have previously been seen as synonymous with the effects of fire severity; however, we found that fire season and severity can have clear and independent, as well as interacting, impacts on post‐fire vegetative growth and reproductive response of resprouting species. Overall, we observed that there were positive effects of autumn fires on reproductive traits, while vegetative growth was positively related to fire severity and pre‐fire plant size.

How Stress Affects Your Budget-Stress Impacts on Starch Metabolism.

Starch is a polysaccharide that is stored to be used in different timescales. Transitory starch is used during nighttime when photosynthesis is unavailable. Long-term starch is stored to support vegetative or reproductive growth, reproduction, or stress responses. Starch is not just a reserve of energy for most plants but also has many other roles, such as promoting rapid stomatal opening, making osmoprotectants, cryoprotectants, scavengers of free radicals and signals, and reverting embolised vessels. Biotic and abiotic stress vary according to their nature, strength, duration, developmental stage of the plant, time of the day, and how gradually they develop. The impact of stress on starch metabolism depends on many factors: how the stress impacts the rate of photosynthesis, the affected organs, how the stress impacts carbon allocation, and the energy requirements involved in response to stress. Under abiotic stresses, starch degradation is usually activated, but starch accumulation may also be observed when growth is inhibited more than photosynthesis. Under biotic stresses, starch is usually accumulated, but the molecular mechanisms involved are largely unknown. In this mini-review, we explore what has been learned about starch metabolism and plant stress responses and discuss the current obstacles to fully understanding their interactions.

Using geographical detection to analyze responses of vegetation growth to climate change in the Loess Pla-teau, China

In order to explore the responses of different vegetation types to climatic change in the Chinese Loess Plateau (CLP), we analzyed the changes of different vegetation types and their relationships with meteorological factors using trend analysis, Hurst index, and geographical detector model based on normalized difference vegetation index (NDVI). The results showed that NDVI of different vegetation types from 2002 to 2019 was dominated by a growing trend and codirectional moderate persistence. The NDVI of crops in the built-up and adjacent areas decreased significantly. Except for grassland or meadow that was affected by mixed pixels, the spatial variation of NDVI was significant in the growing season (from April to October). The mean NDVI of different vegetation types followed an oder: coniferous forest > broadleaved forest > scrub > meadow > grassland > crop > steppe > desert. The interactions between meteorological factors were synergistic and non-linear enhancement in the CLP. Moreover, the interaction was more prominent under steppe and desert where habitat was fragile. The synergistic effect of precipitation and temperature had a great influence on all vegetation types. Water vapor, relative humidity, sunshine duration, atmospheric pressure, and wind speed had different explanatory powers on NDVI through indirectly affec-ting hydrothermal conditions.

Plant Production in Semiarid Shrubland Communities Amended with Biosolids in Central Mexico

Biosolids application in semiarid rangelands has been proposed as a viable alternative for the rehabilitation of degraded soils. We analyzed the effect of rate, time, and number of applications of biosolids per year on the growth of herbaceous vegetation. Summer and winter single applications and a dual application (summer + winter) of biosolids were tested in two soils (calcareous and igneous) of the southern Chihuahuan desert at four rates (0, 3.5, 7, and 10.5 Mg/ha). A single period of vegetation growth occurs in the summer in this region. No major net changes in biomass were recorded with one application of biosolids in the summer or winter applications on both soil types. Winter biosolids application increased the annual species cover on igneous soil. However, annual species cover decreased in the second year on both soil types with one application (summer) or two applications (summer + winter) of biosolids. The lack of synchrony between the availability of NO3-N and moisture may have been the reason for the highly variable response of vegetation growth on calcareous soil. The igneous soil had better soil moisture retention, probably allowing for increased uptake of nitrate by plants. The largest increases in both biomass and plant cover were obtained for perennials with the dual strategy of biosolids application on igneous soil at higher rates. The patterns of plant biomass and cover responses to biosolids application were different on each functional group and soil type. Biosolids application rate and timing are important for enhancing plant productivity in semiarid areas; overall biosolids should be considered as a viable amendment for rangeland restoration.

RESPONS VIABILITAS DAN PERTUMBUHAN VEGETATIF TIGA VARIETAS TANAMAN BAWANG MERAH (Allium ascalonicum L.) ASAL BIJI TRUE SHALLOT SEED (TSS) PADA PERLAKUAN KOMBINASI MEDIA TANAM

The research was aimed to know the response of viability and vegetative growth of three shallots varieties ( Allium ascalonicum L.) from seeds TSS (True Shallot Seed) on combination treatment of plant media. This research was conducted at the Screen House of Center for Protection of Food Crops, horticulture and plantations Serang Province of Banten from September until November 2020. The research used a Randomized Completely Design consisted of two factors. The first factor was the varieties, consisted of three levels were varieties Bima Brebes, Lokananta and Sanren. The second factor was the combination of plant media, consisted of three levels were (soil + compost cow manure), (soil + husk charcoal) and (soil + compost cow manure + husk charcoal). The result showed that varieties Lokananta affected the parameters day of germination (4.56 day), maximum growth potential (87.33%), power germination (87.78%), growth rate (5.78%/day) and percentage normal sprouts (80.89%), height of plant at 14, 21, 28, 35 and 42 DAP (Day After Planting) and number of leaves at 14, 21, 28, 35 and 42 DAP. Combination of plant media soil + husk charcoal gave the best effect on the parameters day of germination (4.67 day), maximum growth potential (88.00%), power germination (88.44%), growth rate (5.76%/day) and percentage normal sprouts (80.67%), height of plant at 14, 21, 28, 35 and 42 DAP and number of leaves at 14, 21, 28, 35 and 42 DAP. There was no interaction between varieties and combination of plant media except for the day of germination parameter.

Vegetative growth response of upland rice to Actinomycetes, Azospirillum and Azotobacter

The research aims is to determine the suitability of nitrogen fixing bacteria, namely Actinomycetes, Azospirillum and Azotobacter with upland rice seeds to the speed of radicle formation and growth of upland rice plants. Upland rice plant growth measurement parameters include; speed of formation of radicle length, upland rice plant height, number of upland rice tillers, dry weight of the top of upland rice plants and roots of upland rice plants, wet weight of upland rice plants and roots of upland rice plants, and total N of upland rice plants and upland roots Testing the application of N2 fixing bacteria on upland rice plants on a laboratory scale was carried out to determine the suitability of microbes with upland rice plant seeds in vitro. The pot test was carried out to determine the suitability of the N2 fixing bacteria with the vegetative growth of upland rice plants in vivo. Data were analyzed using ANOVA with Duncan’s advanced test. The results showed that upland rice plants inoculated with Actinomycetes, Azospirillum and Azotobacter showed significantly different growth from upland rice plants without nitrogen fixing bacteria treatment, namely the radicle formation speed and radicle length, plant height, number of tillers, wet weight, dry weight, and total N (%) plants. It can be concluded that the inoculation of nitrogen-fixing bacteria on upland rice plants has a significant effect on plant vegetative growth parameters and plant nitrogen content.

Boron requirement for vegetative growth of Sacha inchi (Plukentia volubilis L.)

Sachi inchi is a useful traditional plant in South America that has recently gained notoriety as a nutritional food crop and hence is being cultivated outside its native range. In Thailand, the crop is being grown on soils where boron (B) may be limiting to growth. To determine the response of early vegetative growth of sacha inchi to B supply, to identify B deficiency symptoms, and to define leaf B concentrations for optimum growth. The two experiments were conducted in sand-culture pot arranged in a randomized complete block design with three independent replications. Plants were grown in the preliminary experiment consisted of complete nutrient solution and complete nutrient solution without B. The main experiment was continued by growing plants in the five series of B rate (0, 2.5, 5.0, 7.5 and 10.0 µM B). Plant growth parameters were recorded and B concentration in different plant parts were analyzed. B deficiency strongly inhibited root and shoot development causing stunting and organ malformation. In a sand-culture experiment, maximum growth was obtained with 7.5 µM B and 10 µM B reduced growth. Leaf B concentration of 27–29 mg kg−1 was associated with 90% of maximum vegetative yield. Symptoms of B deficiency and the foliar B concentrations are useful for extension workers and producers looking to improve the productivity of sacha inchi on nutrient poor soils.

Response of vegetative and fruit growth to the soil volume wetted by irrigation in a super-high-density olive orchard

In most fruit tree orchards under localised irrigation, only a fraction of the rhizosphere is wetted by irrigation. As this may reduce growth and production, such that there is a demand for information on the optimum number and location of emitters. In a mature ‘Arbequina’ olive orchard with 1667 trees ha-1, we analysed the impact of applying the same amount of water with one vs. two drip irrigation pipes (laterals) per tree row. We had trees under full irrigation, for which irrigation supplies amounted to 80–100% of the crop water needs (ETc), and two deficit irrigation treatments supplying ca. 40% of ETc. We used the HYDRUS 2D/3D (v. 1.11) model to simulate the shape and volume of the fraction of the rhizosphere wetted by irrigation (irrigation bulbs), as well as drainage and soil evaporation. For both full irrigation and deficit irrigation, differences in the soil volume and the soil surface wetted by irrigation were not sufficient to affect drainage and soil evaporation. The greatest values of root length density and root surface per unit volume were found in trees under deficit irrigation with two laterals, and the lowest in fully irrigated trees with one lateral. This, however, was counterbalanced by both the greater size of the irrigation bulbs and the greater soil water contents in the bulbs of the fully irrigated trees, such that water uptake was not enhanced by the second lateral. For 2 consecutive years we found no impact of irrigating with one or two laterals per tree row on water potential and stomatal conductance, shoot and fruit growth, leaf area and production, either for full irrigation or deficit irrigation conditions. Therefore, our findings suggest no benefits of irrigating super high density olive orchards with two laterals instead of one.

Satellite-derived NDVI underestimates the advancement of alpine vegetation growth over the past three decades.

Satellite-derived normalized difference vegetation index (NDVI) data are increasingly relied on to reveal the growth responses of vegetation to climate change, yet the vegetation growth tracking accuracy of these data remains unclear due to a lack of long-term field data. Here, we adopted a unique field-measured seasonal aboveground biomass dataset from 1982-2014 to assess the potential of using satellite-derived NDVI data to match field data in regard to the interannual variability in seasonal vegetation growth in a Tibetan alpine grassland. We revealed that Global Inventory Monitoring and Modeling System (GIMMS) NDVI data captured the advancement of field-measured vegetation growth throughout the entire study period but not from 2000-2014, while MODIS NDVI data still observed this advancing trend after 2000 to a limited extent. However, satellite-derived NDVI data consistently underestimated the advancement degree of field-measured vegetation growth, regardless of whether GIMMS or MODIS NDVI data were considered. We tentatively attribute this underestimation to an increased ratio of grass biomass to forb biomass, which could delay the advancement of NDVI development but not affect that of field-measured biomass development. Our results suggest that satellite-derived NDVI data may miss critical responses of vegetation growth to global climate change, potentially due to long-term shifts in plant community composition.

Relative contributions of natural and man-made factors to vegetation cover change of environmentally sensitive and vulnerable areas of China

Vegetation in arid and semi-arid regions is extremely sensitive to climate change and human activities, and when disturbed, it is prone to irreversible degradation. However, the mechanisms of how natural and anthropogenic factors drive vegetation variations remain unclear for environmentally sensitive and vulnerable areas. To understand the relationships between vegetation variation, climate change, human activities, relief degree of the land surface, and El Niño-Southern Oscillation (ENSO), trend analysis, partial correlation analysis, residual trend (RESTREND), and wavelet coherence approach were utilized. Normalized difference vegetation index (NDVI), meteorological data, and ENSO were used as data sources to determine the spatial response of vegetation growth to climate change and human activity from 1982 to 2018. This study defined the 400 mm annual precipitation fluctuation zone in China (APFZC) for the first time, involving 15 provinces, accounting for 27.37% of China. Vegetation activity was mainly driven by precipitation, temperature, sunshine duration, and wind speed. Precipitation and temperature promoted vegetation activity, while the wind speed inhibited it. Moreover, vegetation variation exerts an obvious topographic effect and is deeply affected by ENSO. Under the influence of climate change from 1982 to 2018, the vegetation became greener in the Loess Plateau, North China Plain, Qinghai, and the border regions of Inner Mongolia and Liaoning; however, in the northeastern part of Inner Mongolia and the western part of Heilongjiang, vegetation was browning. In 1982–1998 and 1999–2018, the contribution rates of climate change to vegetation variation were 50.36% and 42.89%, respectively, and human activities were 49.64% and 57.11%, respectively. This information is crucial for alleviating climate change and for the ecological restoration of vegetation, especially in environmentally sensitive and vulnerable areas.

Regional-scale vegetation-climate interactions on the Qinghai-Tibet Plateau

Response and feedback of vegetation growth to climate change are a series biogeophysical processes from local to regional scales. Revealing the vegetation-climate interaction is fundamental to understand the evolution of earth surface system in the context of global climate change. Due to the low temperature and vulnerable biotic and abiotic settings, the alpine ecosystems are sensitive to climate change, peculiarly in the Qinghai-Tibet Plateau (QTP). By combining the climate factors (precipitation and temperature) and vegetation state indicated by the Enhanced Vegetation Index (EVI) data we try to reveal the pertinent temporal reaction mode of vegetation to climate change on the QTP. The vegetation-climate interactions were investigated by using the Granger causality test technique. The prime findings of this study are: (1) vegetation showed a strong sensitivity to warming-wetting climate in most arid and semi-arid areas of the QTP; (2) the reaction patterns of EVI to precipitation show a temporal lag of 0–1 months, which was strongest to the cumulative precipitation within 1–2 months; (3) The time lag effect and cumulative effect of temperature on vegetation both occurred within 1 to 2 months; (4) The unidirectional Granger causes of precipitation and temperature to vegetation accounted for 17.65% and 8.66% of the entire QTP, respectively. This study emphasizes a sensitive response of the vegetation to climate change (precipitation and temperature) in the QTP. Vegetation feedback makes the fluctuations and effects of climate more complicated. The results indicated that more insights into the future forecasting of climate change and vegetation dynamics can be acquired by a specific and comprehensive analysis of vegetation-climate coupled feedback.

Recent vegetation browning and its drivers on Tianshan Mountain, Central Asia

The strong signal of vegetation increases since the 1980s is considered as reliable evidence of anthropogenic climate change. However, some studies have alerted us to the recent stalling or even reversal of vegetation greening. To determine whether vegetation browning exists on Tianshan Mountain, we investigated the changes in the Normalized Difference Vegetation Index (NDVI) based on long-term satellite-derived NDVI data series from 1982 to 2015. Although the trend of growing season NDVI was statistically significant throughout the study period (0.0006a−1, p < 0.01), two different periods with opposite trends were evident around 1998. The NDVI showed a significant increase before 1998 but a reversal after 1998, when vegetation browning began to appear. The strong correlation between the interannual variability of vegetation and growing season temperature only existed in wet years, indicating that vegetation on Tianshan Mountain is extremely vulnerable and sensitive to water deficits. Our results also suggest that relative to high vapor pressure deficit, soil moisture deficit played a greater role in the recent browning of vegetation on Tianshan Mountain. This study is of scientific value in understanding the response of vegetation growth and carbon cycling to environmental changes and predicting future developments.

A Systematic Review of Melatonin in Plants: An Example of Evolution of Literature.

Melatonin (N-acetyl-5-methoxy-tryptamine) is a mammalian neurohormone, antioxidant and signaling molecule that was first discovered in plants in 1995. The first studies investigated plant melatonin from a human perspective quantifying melatonin in foods and medicinal plants and questioning whether its presence could explain the activity of some plants as medicines. Starting with these first handful of studies in the late 1990s, plant melatonin research has blossomed into a vibrant and active area of investigation and melatonin has been found to play critical roles in mediating plant responses and development at every stage of the plant life cycle from pollen and embryo development through seed germination, vegetative growth and stress response. Here we have utilized a systematic approach in accordance with the preferred reporting items for systematic reviews and meta-analyses (PRISMA) protocols to reduce bias in our assessment of the literature and provide an overview of the current state of melatonin research in plants, covering 1995–2021. This review provides an overview of the biosynthesis and metabolism of melatonin as well as identifying key themes including: abiotic stress responses, root development, light responses, interkingdom communication, phytohormone and plant signaling. Additionally, potential biases in the literature are investigated and a birefringence in the literature between researchers from plant and medical based which has helped to shape the current state of melatonin research. Several exciting new opportunities for future areas of melatonin research are also identified including investigation of non-crop and non-medicinal species as well as characterization of melatonin signaling networks in plants.

Vegetative Growth Response of Tomato (Solanum lycopersicum L) Due to Different Doses of Horse Manure Bokashi

Tomato is an annual plant that can grow well in the territory of Indonesia. Tomato growth is determined by the availability of nutrients in the growing media. The availability of nutrients can be increased by fertilization. Research on Vegetative Growth Response of Tomato (Solanum lycopersicum L) Due to Different Doses of Horse Manure Bokashi has been carried out in Bajur Villagre, West Lombok Regency. This research aims to determine: (1) the effect of different doses of horse manure bokashi to the growth of tomato, (2) the optimum dose of horse manure bokashi that need to be given to agricultural land so that tomato can grom optimaly. In this research, a completely randomized design was used. Horse manure bokashi treatment consisted of 6 levels with 4 replications. The growth parameters were stem height, number of leaves, leaf lenght and leaf widh which were measured 42 days after planting. The research data were analyzed by analysis of variance. The result showed that: (1) different doses of horse manure bokashi significantly affected stem height, number of leaf, leaf lenght and leaf width of tomatoes, (2) the optimum dose of horse manure bokashi that need to be given to agricultural land so that tomato can grom optimaly is 1,6 kg for 1 m2 of agricultural land.

Effect of Foliar Application with Faba Bean and Chickpeas Seed Sprout Extract on Growth and Fruiting of Ewaise Mango Trees

An experiment was conducted during two successive seasons 2019 and 2020 on mango trees cv. Ewaise to study the effect of foliar application faba bean and chickpea seed sprout extract at 0.25 to 1% applied three times along each season (at growth start, fruit set after immediately and one month later) either each extract was sprayed. The influence was evaluated through the response of vegetative growth, leaf N, P, K content, yield and some fruit physical and chemical characteristics.

Divergent Response of Vegetation Growth to Soil Water Availability in Dry and Wet Periods Over Central Asia

AbstractVegetation growth is interactively controlled by hydrothermal conditions and the associated biophysiological changes. These factors have experienced dramatic changes over the past decades in Central Asia, where vegetation growth is primarily constrained by soil water availability. However, we have limited understanding of the time scales and the underlying drivers for the responses of vegetation growth to variations in soil water availability between wet and dry periods. Here, we explored the response of vegetation growth to decadal‐scale hydroclimatic variations in wet versus dry periods, during 1992–2015, using remote sensing retrievals of normalized difference vegetation index and multiple climate factors. We discovered divergent responses of vegetation growth to soil water availability, measured by soil moisture content (SM), between wet and dry periods, with spatiotemporally intensified correlation to SM in the dry period. We revealed a unanimous 1‐month time lag in the response of vegetation growth to SM in the dry period, contrary to much longer time lags and a more spatially heterogeneous response in the wet period. The divergent vegetation responses to SM can be largely explained by the variations in hydroclimatic conditions and spring phenology. The intensified vegetation growth‐SM response in the dry period was strongly associated with increased temperature and vapor pressure deficit. Earlier spring phenology exerts a crucial role in mediating the relationship between vegetation growth and SM in the dry period. The complicated interactions between vegetation phenology and hydroclimatic variations should be explicitly considered in predicting regional vegetation growth under a warmer and drier climate regime in water‐stressed regions.