Relationships between nitrogen, acid-unhydrolyzable residue, and climate among tree foliar litters

2013 ◽  
Vol 43 (1) ◽  
pp. 103-107 ◽  
Author(s):  
Björn Berg ◽  
Chunjiang Liu ◽  
Ryszard Laskowski ◽  
Matthew Davey

Using literature data, we investigated coniferous and broadleaf litter from 58 tree species using a database encompassing concentrations of N and acid-unhydrolyzable residue (AUR) (gravimetric lignin) in newly shed litter, mean annual temperature, and mean annual precipitation. Our aims were to (i) demonstrate any large-scale relationships between concentrations of N and AUR in foliar litter and (ii) determine differences in this respect among litter from Pinus and Quercus. To this end, we had collected foliar litter data for Asia and Europe, forming a climate gradient. Litter from broadleaf and coniferous trees differed significantly in concentrations of N (p < 0.0001, 9.64 versus 5.50 mg/g, respectively) and AUR (p < 0.0001, 219 versus 292 mg/g, respectively). There were highly significant positive linear relationships between concentrations of N and AUR for broadleaf (p < 0.0001) and coniferous litter (p < 0.0001). There were also significant positive relationships for AUR as a function of N concentration for the genera Pinus and Quercus but not within species. That for Scots pine (Pinus sylvestris L.) was negative and that for common oak (Quercus robur L.) not significant.

2018 ◽  
Vol 15 (12) ◽  
pp. 3703-3716 ◽  
Author(s):  
Alexandre A. Renchon ◽  
Anne Griebel ◽  
Daniel Metzen ◽  
Christopher A. Williams ◽  
Belinda Medlyn ◽  
...  

Abstract. Predicting the seasonal dynamics of ecosystem carbon fluxes is challenging in broadleaved evergreen forests because of their moderate climates and subtle changes in canopy phenology. We assessed the climatic and biotic drivers of the seasonality of net ecosystem–atmosphere CO2 exchange (NEE) of a eucalyptus-dominated forest near Sydney, Australia, using the eddy covariance method. The climate is characterised by a mean annual precipitation of 800 mm and a mean annual temperature of 18 ∘C, hot summers and mild winters, with highly variable precipitation. In the 4-year study, the ecosystem was a sink each year (−225 g C m−2 yr−1 on average, with a standard deviation of 108 g C m−2 yr−1); inter-annual variations were not related to meteorological conditions. Daily net C uptake was always detected during the cooler, drier winter months (June through August), while net C loss occurred during the warmer, wetter summer months (December through February). Gross primary productivity (GPP) seasonality was low, despite longer days with higher light intensity in summer, because vapour pressure deficit (D) and air temperature (Ta) restricted surface conductance during summer while winter temperatures were still high enough to support photosynthesis. Maximum GPP during ideal environmental conditions was significantly correlated with remotely sensed enhanced vegetation index (EVI; r2 = 0.46) and with canopy leaf area index (LAI; r2 = 0.29), which increased rapidly after mid-summer rainfall events. Ecosystem respiration (ER) was highest during summer in wet soils and lowest during winter months. ER had larger seasonal amplitude compared to GPP, and therefore drove the seasonal variation of NEE. Because summer carbon uptake may become increasingly limited by atmospheric demand and high temperature, and because ecosystem respiration could be enhanced by rising temperatures, our results suggest the potential for large-scale seasonal shifts in NEE in sclerophyll vegetation under climate change.


2018 ◽  
Vol 15 (17) ◽  
pp. 5329-5341 ◽  
Author(s):  
Jiguang Feng ◽  
Jingsheng Wang ◽  
Yanjun Song ◽  
Biao Zhu

Abstract. Soil respiration (Rs), a key process in the terrestrial carbon cycle, is very sensitive to climate change. In this study, we synthesized 54 measurements of annual Rs and 171 estimates of Q10 value (the temperature sensitivity of soil respiration) in grasslands across China. We quantitatively analyzed their spatial patterns and controlling factors in five grassland types, including temperate typical steppe, temperate meadow steppe, temperate desert steppe, alpine grassland, and warm, tropical grassland. Results showed that the mean (±SE) annual Rs was 582.0±57.9 g C m−2 yr−1 across Chinese grasslands. Annual Rs significantly differed among grassland types, and was positively correlated with mean annual temperature, mean annual precipitation, soil temperature, soil moisture, soil organic carbon content, and aboveground biomass, but negatively correlated with soil pH (p<0.05). Among these factors, mean annual precipitation was the primary factor controlling the variation of annual Rs among grassland types. Based on the overall data across Chinese grasslands, the Q10 values ranged from 1.03 to 8.13, with a mean (±SE) of 2.60±0.08. Moreover, the Q10 values varied largely within and among grassland types and soil temperature measurement depths. Among grassland types, the highest Q10 derived by soil temperature at a depth of 5 cm occurred in alpine grasslands. In addition, the seasonal variation of soil respiration in Chinese grasslands generally cannot be explained well by soil temperature using the van't Hoff equation. Overall, our findings suggest that the combined factors of soil temperature and moisture would better predict soil respiration in arid and semi-arid regions, highlight the importance of precipitation in controlling soil respiration in grasslands, and imply that alpine grasslands in China might release more carbon dioxide to the atmosphere under climate warming.


2020 ◽  
Author(s):  
Lisa Zwanzig ◽  
Martin Zwanzig ◽  
Daniela Sauer

&lt;p&gt;Soil formation is controlled by climate, vegetation, organisms, topography, parent material and time. There are various hypotheses on the relative importance of these individual soil-forming factors. The quantitative influence of each soil-forming factor on the expression and rates of soil-forming processes, and in particular the influence of the different factors in combination, have not yet been sufficiently analyzed. The aim of this study was to quantify the influence of the soil-forming factors on the rates of podzolization. For this purpose, we compiled published data from 46 soil chronosequence studies in a database. These studies contained altogether 231 soil profiles of known age, on which we tested existing hypotheses on the influence of different soil-forming factors. The formation of an E horizon and its increase in thickness over time is one of the characteristic features of Podzol formation. As it is one of the few features that was described in all 46 studies, we used it as an indicator of progressive podzolization. Through statistical analysis, we investigated how E horizon thickness is affected by latitude, longitude, mean annual precipitation, mean annual temperature, range between minimum and maximum monthly temperature, annual number of days with frost, vegetation class (pioneer, deciduous and coniferous), sand content, clay content, and soil age.&lt;/p&gt;&lt;p&gt;Since E horizon thickness exhibited a zero-inflated (semi-)continuous distribution, we opted for a zero-altered gamma (ZAG) model, consisting of a Bernoulli and a Gamma part. The Bernoulli part shows, how the probability of the presence of an E horizon changes with soil age and environmental conditions. The Gamma part of the ZAG model allows for capturing the effects of the covariates on E horizon thickness. Our results indicate that vegetation is the most important factor for both (1) the soil age at which podzolization starts (used indicator: first occurrence of an E horizon), and (2) the rates of podzolization thereafter (used measure: increase of E horizon thickness with soil age). Climatic factors such as mean annual precipitation and range of temperature play subordinate roles. They are important for the soil age at which podzolization starts but less important for the rates of podzolization. We did not identify a significant influence of sand content, neither on the start nor the rates of podzolization. Thus, this statistical assessment of global data provides new insights into the relative importance of the individual soil-forming factors on the onset and temporal course of podzolization.&lt;/p&gt;


Botany ◽  
2013 ◽  
Vol 91 (8) ◽  
pp. 514-529 ◽  
Author(s):  
Richard M. Dillhoff ◽  
Thomas A. Dillhoff ◽  
David R. Greenwood ◽  
Melanie L. DeVore ◽  
Kathleen B. Pigg

A flora from Thomas Ranch near Princeton, British Columbia, Canada, is assessed for biodiversity and paleoclimate. This latest Early to early Middle Eocene flora occurs in the Allenby Formation. Seventy-six megafossil morphotypes have been recognized, representing at least 62 species, with 29 identified to genus or species. Common taxa include Ginkgo L., Metasequoia Miki, Sequoia Endl., Abies Mill., Pinus L., Pseudolarix Gordon, Acer L., Alnus Mill., Betula L., Fagus L., Sassafras J Presl, Macginitiea Wolfe & Wehr, Prunus L., and Ulmus L. More than 70 pollen and spore types are recognized, 32 of which are assignable to family or genus. The microflora is dominated by conifers (85%–97% abundance), with Betulaceae accounting for most of the angiosperms. The Climate Leaf Analysis Multivariate Program (CLAMP) calculates a mean annual temperature (MAT) of 9.0 ± 1.7 °C and bioclimatic analysis (BA) calculates a MAT of 12.8 ± 2.5 °C. Coldest month mean temperature (CMMT) was >0 °C. Mean annual precipitation (MAP) was >70 cm/year but is estimated with high uncertainty. Both the CLAMP and BA estimates are at the low end of the MAT range previously published for other Okanagan Highland localities, indicating a temperate climate consistent with a mixed conifer–deciduous forest.


2021 ◽  
Vol 13 (12) ◽  
Author(s):  
Sara E. Rhodes ◽  
Nicholas J. Conard

AbstractEnsuring comparability between results is a key goal of all paleoecological reconstructions. Quantitative estimates of meteorological variables, as opposed to relative qualitative descriptions, provide the opportunity to compare local paleoenvironmental records against global estimates and incrementally build regional paleoclimatic records. The Bioclimatic Method provides quantitative and qualitative estimates of past landscape composition and climate along with measures of statistical accuracy by applying linear discriminant functions analysis and transfer functions to faunal taxonomic abundance data. By applying this method to the rodent data from Geißenklösterle and Hohle Fels, two Paleolithic cave sites located in the Ach Valley of southwestern Germany, we classify the regional vegetation according to Walters’ zonobiome model. We also present new estimates of meteorological variables including mean annual temperature, mean annual precipitation, and vegetative activity period of the Ach Valley for the period spanning ~ 60,000 to 35,000 cal BP. The results suggest the Ach Valley contained a non-analogous landscape of arctic tundra and temperate deciduous woodland with occasional arid steppe expansion. Meteorological estimates suggest the climate was significantly colder during the Middle and Upper Paleolithic than today, with higher annual precipitation and dramatic temperature shifts between seasons. These results fit well with climatic reconstructions from Switzerland and the Netherlands based on a variety of proxies. They also provide further evidence of a localized climatic response within southwestern Germany to the stadial-interstadial shifts preceding the Heinrich 4 event. Finally, these results reinforce our previous claims that climatic volatility was not a driving force in the loss of Neanderthal groups throughout the Swabian Jura during OIS 3.


Forests ◽  
2019 ◽  
Vol 10 (5) ◽  
pp. 403 ◽  
Author(s):  
Jacek Kamczyc ◽  
Marcin K. Dyderski ◽  
Paweł Horodecki ◽  
Andrzej M. Jagodziński

Replacement of native deciduous forests by coniferous stands was a common result of former European afforestation policies and paradigms of forest management and led to considerable ecological consequences. Therefore, the most popular management strategy nowadays in multi-functional forestry is the re-establishment of mixed or broadleaved forests with native species on suitable habitats. However, our knowledge about the effects of tree species introduced into coniferous monocultures on soil mesofauna communities is scarce. We investigated abundance, species richness and diversity of Mesostigmata mite communities in decomposed litter of seven broadleaved (Acer platanoides L., A. pseudoplatanus L., Carpinus betulus L., Fagus sylvatica L., Tilia cordata Mill., Quercus robur L., Q. rubra L.) and four coniferous (Abies alba Mill., Larix decidua Mill., Picea abies [L.] Karst., Pinus sylvestris L.) species. We collected 297 litterbags after 6, 12 and 18 months of exposition in Scots pine (Pinus sylvestris) monocultures in Siemianice Experimental Forest (SW Poland). Generally, species richness and diversity in litter samples were much lower than in the soil mite pool. The highest abundance was found in P. sylvestris and A. alba litter, while the lowest was found in A. platanoides. The most abundant families were Zerconidae, Parasitidae, Veigaiidae, and Trachytidae. Our study revealed that neither species richness nor diversity were affected, but that mite abundance was affected, by the tree species (litter quality). The mite communities were similarly comprised in both high- and low-quality litter and mite abundance decreased during the decomposition process in nutrient-poor Scots pine forests. Moreover, few mite species benefited from the decomposed litter. Additionally, a litter of various tree species was inhabited mainly by eu- and hemiedaphic mite species. Mite assemblages in A. alba, P. sylvestris, and Q. robur litter had higher abundances. Exposition time seems to be an important driver in shaping the mite community during the early stages of litter decomposition.


Sign in / Sign up

Export Citation Format

Share Document