scholarly journals Coupled influence of precipitation regimes and seedling emergence time on the reproductive strategy in Chloris virgata

PeerJ ◽  
2020 ◽  
Vol 8 ◽  
pp. e8476
Author(s):  
Ying Wang ◽  
Jiawei Chen ◽  
Yige Huang ◽  
Zhongsheng Mu ◽  
Changfu Wang
Keyword(s):  
Seed Size ◽  
Reproductive Strategy ◽  
Seedling Emergence ◽  
Tiller Number ◽  
Seed Number ◽  
Emergence Time ◽  
Precipitation Regime ◽  
Precipitation Regimes ◽  
Chloris Virgata ◽  
Low Precipitation

Precipitation regime and seedling emergence time both influence plant growth and reproduction. However, little attention has been given to the effects of these combined factors on the reproductive strategy of Chloris virgata, which is a vital species in Songnen grassland. Here, we simulated the changes in the precipitation regime and seedling emergence time to evaluate tiller traits and seed production. The results showed that tiller number behaved similarly among three precipitation regimes when sowed on 15 May (T1), while it increased significantly with precipitation regimes when sowed on 15 June (T2) and 15 July (T3). Tiller number decreased significantly with the seedling emergence time under the same water supply treatment. The proportional allocation of reproductive tiller number to total tiller number was significantly higher at T3 than at T1 and T2. Seed number remained similar under different precipitation regimes at T2 and T3, whereas it was significantly lower under low precipitation than under other water levels at T1. Seed number reached the maximum values at T2 under the same level of precipitation treatment. Seed size was significantly lower under low precipitation compared to other water supply treatments and the lowest values in seed size, about 0.5 mg, occurred at T2 under all the precipitation regimes. The lowest values in spike number were under low precipitation at all seedling emergence times. Seed yield exhibited similar trends with seed size under different precipitation regimes, while the greatest gains in these values were at T1 under all the precipitation regimes. Our findings showed that simulated precipitation regimes and seedling emergence time affected the reproductive strategy of C. virgata. Typical and high precipitation, as well as early seedling emergence, will improve the seed yield and seed quality in this species.

scholarly journals The reproductive strategy in a Chloris virgata population in response to precipitation regimes

2018 ◽  
Vol 5 (8) ◽  
pp. 180607 ◽  
Author(s):  
Wang Ying ◽  
Wang Chunxia ◽  
Zhang Jukui ◽  
Wang Chunqing
Keyword(s):  
Seed Size ◽  
Reproductive Strategy ◽  
Seed Mass ◽  
Seed Traits ◽  
Seed Number ◽  
Water Addition ◽  
Precipitation Regimes ◽  
High Precipitation ◽  
Chloris Virgata ◽  
Low Precipitation

Resource availability influences plant growth and reproduction. Here, a controlled experiment was conducted in order to evaluate the adaptation response of Chloris virgata to different precipitation conditions, and to further predict the reproductive strategy in a population of C. virgata under different precipitation regimes. Three regimes (low, typical and high) of water addition were used to simulate current precipitation patterns. In total 20 individuals for each treatment were analysed to compare tiller number, spike traits, seed traits, the relationship between seed size and seed number, and so on. In addition, the effects of different precipitation regimes on offspring vigour of C. virgata were also studied. Results indicated that tiller number, spike number, seed yield and seed number were unchanged under different water addition regimes, while seed size was about 0.5 mg at typical and high precipitation levels and was higher than that in the low precipitation level. The higher seed mass per spike and spike mass both occurred at typical and high precipitation levels. Significant positive correlations between seed mass and non-seed mass in C. virgata in response to precipitation regimes were largely allometric (size dependent), as was a significant negative correlation between seed size and seed number at low precipitation. The highest germination rates and seedling weights both occurred at typical and high precipitation levels. These findings showed that different precipitation regimes affected reproductive strategy of C. virgata. Chloris virgata will not benefit from low precipitation, while typical and high precipitation will improve seed traits and offspring vigour of this species.

Reproduction strategy of Chloris virgata under simulated atmospheric nitrogen deposition

2015 ◽  
Vol 66 (5) ◽  
pp. 516 ◽  
Author(s):  
Wang Changfu ◽  
Wang Ying
Keyword(s):  
Seed Size ◽  
N Deposition ◽  
Control Treatment ◽  
Reproductive Pattern ◽  
Atmospheric Nitrogen ◽  
Seed Number ◽  
Atmospheric N Deposition ◽  
Seed Vigour ◽  
Rhodes Grass ◽  
Chloris Virgata

Atmospheric nitrogen (N) deposition is an important issue of global climate change and it will significantly affect plant growth and reproduction, resulting in damage to ecological systems. However, little attention has been given to the effects of this factor on plant reproductive strategies. We investigated how variation in atmospheric N deposition affects the reproductive strategy of Chloris virgata (feathertop Rhodes grass). We simulated atmospheric N deposition to evaluate the trade-off between seed size and seed number, as well as its effects on offspring vigour. We found significant negative correlations between seed size and seed number per spike in the control and 20.0 g N m–2 treatments, as well as between seed size and seed number per plant in the control treatment. Seed number and seed weight per spike behaved similarly and were significantly lower in the control and 20.0 g N m–2 treatments than in the other N supply treatments. Spike number and seed yield behaved similarly, and the greatest gains in these values occurred from 2.5 to 20.0 g N m–2. Seed size reached its maximum values at low and high N levels, whereas seed N concentrations increased with N level. Although the germination percentage remained stable under different N levels, the highest germination rate occurred in the control treatment. Our findings showed that simulated atmospheric N deposition affected the reproductive pattern and seed vigour of C. virgata.

scholarly journals The climatic imprint of bimodal distributions in vegetation cover for western Africa

2016 ◽  
Vol 13 (11) ◽  
pp. 3343-3357 ◽  
Author(s):  
Zun Yin ◽  
Stefan C. Dekker ◽  
Bart J. J. M. van den Hurk ◽  
Henk A. Dijkstra
Keyword(s):  
Land Cover ◽  
Congo Basin ◽  
Shortwave Radiation ◽  
Mean Annual Precipitation ◽  
Above Ground Biomass ◽  
Precipitation Regime ◽  
Ground Biomass ◽  
Western Africa ◽  
Precipitation Regimes ◽  
Woody Cover

Abstract. Observed bimodal distributions of woody cover in western Africa provide evidence that alternative ecosystem states may exist under the same precipitation regimes. In this study, we show that bimodality can also be observed in mean annual shortwave radiation and above-ground biomass, which might closely relate to woody cover due to vegetation–climate interactions. Thus we expect that use of radiation and above-ground biomass enables us to distinguish the two modes of woody cover. However, through conditional histogram analysis, we find that the bimodality of woody cover still can exist under conditions of low mean annual shortwave radiation and low above-ground biomass. It suggests that this specific condition might play a key role in critical transitions between the two modes, while under other conditions no bimodality was found. Based on a land cover map in which anthropogenic land use was removed, six climatic indicators that represent water, energy, climate seasonality and water–radiation coupling are analysed to investigate the coexistence of these indicators with specific land cover types. From this analysis we find that the mean annual precipitation is not sufficient to predict potential land cover change. Indicators of climate seasonality are strongly related to the observed land cover type. However, these indicators cannot predict a stable forest state under the observed climatic conditions, in contrast to observed forest states. A new indicator (the normalized difference of precipitation) successfully expresses the stability of the precipitation regime and can improve the prediction accuracy of forest states. Next we evaluate land cover predictions based on different combinations of climatic indicators. Regions with high potential of land cover transitions are revealed. The results suggest that the tropical forest in the Congo basin may be unstable and shows the possibility of decreasing significantly. An increase in the area covered by savanna and grass is possible, which coincides with the observed regreening of the Sahara.

Evaluation of GPROF V05 Precipitation Retrievals under Different Cloud Regimes

2021 ◽  
Keyword(s):  
Discrete Systems ◽  
The United States ◽  
Precipitation Variability ◽  
Substantial Fraction ◽  
Precipitation Regime ◽  
Surface Type ◽  
Precipitation Regimes ◽  
Channel Configuration ◽  
Global Precipitation ◽  
Cloud Regimes

AbstractPrecipitation retrievals from passive microwave satellite observations form the basis of many widely used precipitation products, but the performance of the retrievals depends on numerous factors such as surface type and precipitation variability. Previous evaluation efforts have identified bias dependence on precipitation regime, which may reflect the influence on retrievals of recurring factors. In this study, the concept of a regime-based evaluation of precipitation from the Goddard Profiling (GPROF) algorithm is extended to cloud regimes. Specifically, GPROF V05 precipitation retrievals under four different cloud regimes are evaluated against ground radars over the United States. GPROF is generally able to accurately retrieve the precipitation associated with both organized convection and less organized storms, which collectively produce a substantial fraction of global precipitation. However, precipitation from stratocumulus systems is underestimated over land and overestimated over water. Similarly, precipitation associated with trade cumulus environments is underestimated over land, while biases over water depend on the sensor’s channel configuration. By extending the evaluation to more sensors and suppressed environments, these results complement insights previously obtained from precipitation regimes, thus demonstrating the potential of cloud regimes in categorizing the global atmosphere into discrete systems.

scholarly journals Effects of Sand Burial Depth on Xanthium Spinosum Seed Germination and Seedling Growth

2021 ◽  
Author(s):  
yuanyuan Tao ◽  
Tian-cui Sang ◽  
Jun-jie Yan ◽  
Yun-xia Hu ◽  
Yu Zhao ◽  
...  
Keyword(s):  
Seed Germination ◽  
Seedling Growth ◽  
Seedling Emergence ◽  
Soil Layer ◽  
Burial Depth ◽  
Seedling Height ◽  
Emergence Time ◽  
Deep Soil ◽  
Sand Burial ◽  
Emergence Rate

Abstract different sand burial depths on seed germination, seedling emergence, growth and biomass allocation were studied to provide a scientific basis for further control of X. spinosum. Six sand burial depths (1, 2, 3, 5, 7 and 9 cm) were established to explore the response of X. spinosum seed germination and seedling growth to sand burial. The first emergence time, peak emergence time, emergence rate, seedling growth height, biomass and biomass distribution of X. spinosum seeds had significant effects at different sand burial depths (P < 0.05). The X. spinosum seeds had the highest emergence rate (71.5%) at 1 cm sand burial and the maximum seedling height (7.1 cm). As sand burial depth increased, the emergence rate and seedling height gradually decreased, and the emergence rate (12.25%) and seedling height (2.9 cm) were lowest at 9 cm sand burial. The root length at 9 cm depth (13.6 cm) was significantly higher than that at other sand depths (P < 0.05). The sand burial depth affected the biomass accumulation and distribution of X. spinosum. As sand burial depth increased, the root biomass and rhizome ratio increased, and the most deeply buried seedlings allocated more biomass for root growth. The optimal sand burial depth for seed germination and seedling growth of X. spinosum was 1–3 cm, and high burial depth (5–9 cm) was not conducive to the germination and growth of X. spinosum seedlings. For prevention and control of X. spinosum, we suggest deeply ploughing crops before sowing to ensure X. spinosum seeds are ploughed into a deep soil layer.

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