scholarly journals Precipitation Pattern Alters the Effects of Nitrogen Deposition on the Growth of Alien Species Robinia Pseudoacacia

Author(s):  
Xiao Wang ◽  
Xiao Guo ◽  
Wenli Ding ◽  
Ning Du ◽  
Weihua Guo ◽  
...  

Abstract Aims Nitrogen (N) supply and precipitation pattern (amount and frequency) both affect plant growth. However, N deposition is increasing and precipitation regimes are changing in the context of global change. An experiment was conducted to determine the effect of precipitation pattern and N supplies on the growth of a widely distributed and planted N2-fixing alien species Robinia pseudoacacia. Methods Seedlings were grown in a glasshouse at four different N levels combined with different precipitation regimes, including three precipitation amounts, and two precipitation frequencies. After treatment for 75 days, plant height, biomass allocation, leaf and soil nutrient concentrations were measured. Results Plants under high precipitation frequency had greater biomass compared with plants lower precipitation frequency with the same amount of precipitation. Higher N supply decreased biomass allocation to nodules. Nodule growth and N2 fixation of R. pseudoacacia with low precipitation amount was more inhibited by high N deposition compared with plants received higher precipitation amount. Slightly N deposition under higher precipitation inhibited N2 fixation but did not fulfil the N need in plants. Conclusions Nitrogen deposition might inhibit N2 fixation of plants even in low level but low nitrogen in soil cannot fulfil the N need of plants, and caused N2 fixation limitation in plants during seedling stage. There was likely a shift from acquiring N mainly from N2 fixation to acquisition of N directly with root when N supply was increased. High N deposition level, and increased precipitation frequency might increase the invasion risk of R. pseudoacacia.

2021 ◽  
Author(s):  
Tianxue Yang ◽  
Junda Chen ◽  
Xiaoyue Zhong ◽  
Xuechen Yang ◽  
Gui Wang ◽  
...  

Abstract Purpose Climate models predict shifts in precipitation patterns characterized by increased precipitation amount and decreased frequency for semi-arid grasslands in northeast China. However, under these novel climatic conditions, potential differences in plant biomass and its allocation among different degraded grasslands remain unclear.Methods We conducted a mesocosm experiment to test the effects of higher precipitation amount (increased by 50% from the long-term mean) and lower frequency (decreased by 50%) on plant biomass and allocation in the lightly degraded (LDG), moderately degraded (MDG), and severely degraded grasslands (SDG).Results Lower precipitation frequency promoted belowground biomass (BGB), while reducing aboveground biomass (AGB) allocation through enhancing soil water variability. Higher precipitation amount enhanced AGB in LDG and MDG, but not in SDG due to less soil inorganic nitrogen. Lower precipitation frequency weakened the positive effects of higher precipitation amount on biomass. Under altered precipitation, adjustment of AGB vs. BGB allocation was the primary biomass allocation strategy in LDG and SDG. However, to maintain water acquirement, plants in MDG preferred to adjust root vertical distribution, and allocated more roots to the deep soil layer where had a relatively stable water source. This strategy was driven by the changes in plant community composition of the dominant species in MDG.Conclusions The findings of this research emphasized the importance of considering the degradation level of grasslands when predicting the responses of the ecosystem functions to the projected changes in precipitation regime. These findings are critical for making feasible decisions for the sustainable management of degraded grasslands.


2006 ◽  
Vol 12 (3) ◽  
pp. 470-476 ◽  
Author(s):  
GARETH K. PHOENIX ◽  
W. KEVIN HICKS ◽  
STEVE CINDERBY ◽  
JOHAN C. I. KUYLENSTIERNA ◽  
WILLIAM D. STOCK ◽  
...  

2021 ◽  
Author(s):  
Guanxing Wang ◽  
Fan Zhang

<p>Being an important water resource of the local and downstream living hoods, precipitation amount is experiencing drastic changes in the Babao River basin in the northeast of the Tibetan Plateau. Precipitation types also have great impacts on the runoff. However, in usual cases, weather stations only record precipitation amount without discriminating its type. Here, we compared results from three methods at improving precipitation type (solid and liquid) estimation with discontinuous 24 years precipitation type records of the Qilian gauging station. The results (bias rank of the three methods is 2.5% < 17.3% < 20.1%) showed that the estimation of different thresholds for wet season (4 °C) and dry season (5.5 °C) is the closest to the actual records. Based on the precipitation type distinction, the precipitation type and its amount changing trend in recent 50 years of the Babao River basin was examined. On average, snowfall accounts for 10.7% in whole year, and mainly happens in March, April, May and October (8.9% in whole year). In the context of climate warming, the annual precipitation and rainfall increasing significantly while the annual snowfall decreased slightly. Furthermore, on the perspective of monthly changes, rainfall amounts of May and August enhanced significantly while snowfall amount decreased significantly in June and September. The above conclusions indicated the warming climate also changed the precipitation pattern in the Babao River basin which would likely cause drought in the spring season and bring challenge to the local agriculture.</p>


2020 ◽  
Vol 12 (15) ◽  
pp. 2448
Author(s):  
Alizée Girard ◽  
Anna K. Schweiger ◽  
Alexis Carteron ◽  
Margaret Kalacska ◽  
Etienne Laliberté

Bogs, as nutrient-poor ecosystems, are particularly sensitive to atmospheric nitrogen (N) deposition. Nitrogen deposition alters bog plant community composition and can limit their ability to sequester carbon (C). Spectroscopy is a promising approach for studying how N deposition affects bogs because of its ability to remotely determine changes in plant species composition in the long term as well as shorter-term changes in foliar chemistry. However, there is limited knowledge on the extent to which bog plants differ in their foliar spectral properties, how N deposition might affect those properties, and whether subtle inter- or intraspecific changes in foliar traits can be spectrally detected. The objective of the study was to assess the effect of N deposition on foliar traits and spectra. Using an integrating sphere fitted to a field spectrometer, we measured spectral properties of leaves from the four most common vascular plant species (Chamaedaphne calyculata, Kalmia angustifolia, Rhododendron groenlandicum and Eriophorum vaginatum) in three bogs in southern Québec and Ontario, Canada, exposed to different atmospheric N deposition levels, including one subjected to a 18-year N fertilization experiment. We also measured chemical and morphological properties of those leaves. We found detectable intraspecific changes in leaf structural traits and chemistry (namely chlorophyll b and N concentrations) with increasing N deposition and identified spectral regions that helped distinguish the site-specific populations within each species. Most of the variation in leaf spectral, chemical, and morphological properties was among species. As such, species had distinct spectral foliar signatures, allowing us to identify them with high accuracy with partial least squares discriminant analyses (PLSDA). Predictions of foliar traits from spectra using partial least squares regression (PLSR) were generally accurate, particularly for the concentrations of N and C, soluble C, leaf water, and dry matter content (<10% RMSEP). However, these multi-species PLSR models were not accurate within species, where the range of values was narrow. To improve the detection of short-term intraspecific changes in functional traits, models should be trained with more species-specific data. Our field study showing clear differences in foliar spectra and traits among species, and some within-species differences due to N deposition, suggest that spectroscopy is a promising approach for assessing long-term vegetation changes in bogs subject to atmospheric pollution.


2014 ◽  
Vol 2014 ◽  
pp. 1-9 ◽  
Author(s):  
Yang Wang ◽  
Jingshuang Liu ◽  
Longxue He ◽  
Jingxin Dou ◽  
Hongmei Zhao

The effects of nitrogen deposition (N-deposition) on the carbon dynamics in typicalCalamagrostis angustifoliawetland of Sanjiang Plain were studied by a pot-culture experiment during two continuous plant growing seasons. Elevated atmospheric N-deposition caused significant increases in the aboveground net primary production and root biomass; moreover, a preferential partition of carbon to root was also observed. Different soil carbon fractions gained due to elevated N-deposition and their response intensities followed the sequence of labile carbon > dissolved organic carbon > microbial biomass carbon, and the interaction between N-deposition and flooded condition facilitated the release of different carbon fractions. Positive correlations were found between CO2and CH4fluxes and liable carbon contents with N-deposition, and flooded condition also tended to facilitate CH4fluxes and to inhibit the CO2fluxes with N-deposition. The increases in soil carbon fractions occurring in the nitrogen treatments were significantly correlated with increases in root, aboveground parts, total biomass, and their carbon uptake. Our results suggested that N-deposition could enhance the contents of active carbon fractions in soil system and carbon accumulation in plant of the freshwater wetlands.


2018 ◽  
Vol 23 ◽  
pp. 00004
Author(s):  
Waldemar Bojar ◽  
Leszek Knopik ◽  
Renata Kuśmierek-Tomaszewska ◽  
Jacek Żarski ◽  
Wojciech Żarski

The aim of the research has been to provide a statistical analysis of precipitation in the Bydgoszcz region based on the results of the measurements taken at the Experiment Station of the UTP University of Science and Technology in Bydgoszcz, located at Mochle, about 20 km away from the city centre. The paper analyses the daily total precipitation throughout 43 years (1971—2013). The analysis demonstrated a high dependence of the indicators studied on the month, confirming the annual pattern typical for the transitional climate of the temperate zone. In general, it shows an advantage of the amount and variation, and less considerably — the daily precipitation frequency in summer months, as compared with the winter months. The distribution of the probability of the daily precipitation amount for each month turned out to be compliant with gamma distribution, which allows for a potential variation in the future.


2007 ◽  
Vol 20 (19) ◽  
pp. 4801-4818 ◽  
Author(s):  
Ying Sun ◽  
Susan Solomon ◽  
Aiguo Dai ◽  
Robert W. Portmann

Abstract Daily precipitation data from climate change simulations using the latest generation of coupled climate system models are analyzed for potential future changes in precipitation characteristics. For the Intergovernmental Panel on Climate Change (IPCC) Special Report on Emissions Scenarios (SRES) B1 (a low projection), A1B (a medium projection), and A2 (a high projection) during the twenty-first century, all the models consistently show a shift toward more intense and extreme precipitation for the globe as a whole and over various regions. For both SRES B1 and A2, most models show decreased daily precipitation frequency and all the models show increased daily precipitation intensity. The multimodel averaged percentage increase in the precipitation intensity (2.0% K−1) is larger than the magnitude of the precipitation frequency decrease (−0.7% K−1). However, the shift in precipitation frequency distribution toward extremes results in large increases in very heavy precipitation events (&gt;50 mm day−1), so that for very heavy precipitation, the percentage increase in frequency is much larger than the increase in intensity (31.2% versus 2.4%). The climate model projected increases in daily precipitation intensity are, however, smaller than that based on simple thermodynamics (∼7% K−1). Multimodel ensemble means show that precipitation amount increases during the twenty-first century over high latitudes, as well as over currently wet regions in low- and midlatitudes more than other regions. This increase mostly results from a combination of increased frequency and intensity. Over the dry regions in the subtropics, the precipitation amount generally declines because of decreases in both frequency and intensity. This indicates that wet regions may get wetter and dry regions may become drier mostly because of a simultaneous increase (decrease) of precipitation frequency and intensity.


2012 ◽  
Vol 7 (3) ◽  
pp. 487-494 ◽  
Author(s):  
Beata Borowiak-Sobkowiak ◽  
Roma Durak

AbstractElements of the biology and ecology of A. robiniae were studied in Poland during the period of 2008–2009. The term of spring hatching, number of generations per season, developmental time of particular generations, lifespan of specimens and fecundity of particular generations were all defined. The dynamics of the species’ occurrence on its host plant were also determined. The two-year study showed a maximum of 11 aphid generations can develop on Robinia pseudoacacia. Females of the second and third generations were found to be the most fertile. These findings indicate that the species has adapted well in Poland and its biological predispositions have enabled it to rapidly increase in population.


2012 ◽  
Vol 367 (1606) ◽  
pp. 3125-3134 ◽  
Author(s):  
Zhichun Lan ◽  
Yongfei Bai

The increase in nutrient availability as a consequence of elevated nitrogen (N) deposition is an important component of global environmental change. This is likely to substantially affect the functioning and provisioning of ecosystem services by drylands, where water and N are often limited. We tested mechanisms of chronic N-enrichment-induced plant species loss in a 10-year field experiment with six levels of N addition rate. Our findings on a semi-arid grassland in Inner Mongolia demonstrated that: (i) species richness (SR) declined by 16 per cent even at low levels of additional N (1.75 g N m –2 yr −1 ), and 50–70% species were excluded from plots which received high N input (10.5–28 g N m −2 yr −1 ); (ii) the responses of SR and above-ground biomass (AGB) to N were greater in wet years than dry years; (iii) N addition increased the inter-annual variations in AGB, reduced the drought resistance of production and hence diminished ecosystem stability; (iv) the critical threshold for chronic N-enrichment-induced reduction in SR differed between common and rare species, and increased over the time of the experiment owing to the loss of the more sensitive species. These results clearly indicate that both abundance and functional trait-based mechanisms operate simultaneously on N-induced species loss. The low initial abundance and low above-ground competitive ability may be attributable to the loss of rare species. However, shift from below-ground competition to above-ground competition and recruitment limitation are likely to be the key mechanisms for the loss of abundant species, with soil acidification being less important. Our results have important implications for understanding the impacts of N deposition and global climatic change (e.g. change in precipitation regimes) on biodiversity and ecosystem services of the Inner Mongolian grassland and beyond.


2006 ◽  
Vol 3 (5) ◽  
pp. 317 ◽  
Author(s):  
Ole Hertel ◽  
Carsten Ambelas Skjøth ◽  
Per Løfstrøm ◽  
Camilla Geels ◽  
Lise Marie Frohn ◽  
...  

Abstract. Local ammonia emissions from agricultural activities are often associated with high nitrogen deposition in the close vicinity of the sources. High nitrogen (N) inputs may significantly affect the local ecosystems. Over a longer term, high loads may change the composition of the ecosystems, leading to a general decrease in local biodiversity. In Europe there is currently a significant focus on the impact of atmospheric N load on local ecosystems among environmental managers and policy makers. Model tools designed for application in N deposition assessment and aimed for use in the regulation of anthropogenic nitrogen emissions are, therefore, under development in many European countries. The aim of this paper is to present a review of the current understanding and modelling parameterizations of atmospheric N deposition. A special focus is on the development of operational tools for use in environmental assessment and regulation related to agricultural ammonia emissions. For the often large number of environmental impact assessments needed to be carried out by local environmental managers there is, furthermore, a need for simple and fast model systems. These systems must capture the most important aspects of dispersion and deposition of N in the nearby environment of farms with animal production. The paper includes a discussion on the demands on the models applied in environmental assessment and regulation and how these demands are fulfilled in current state-of-the-art models.


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