Interactions between Callitris above-ground biomass, species density and plant form in north-eastern New South Wales

2013 ◽  
Vol 61 (1) ◽  
pp. 73 ◽  
Author(s):  
John T. Hunter

Dense Callitris endlicheri (Parl.) F.M.Bailey (black cypress pine) and C. glaucophylla Joy Thomps. & L.A.S.Johnson (white cypress pine) stands are often viewed as problematic and thinning is often encouraged from a biodiversity perspective. In the present investigation, canonical correspondence analyses (CCAs) of 997 survey sites were undertaken within the public and private reserve network that contains a variety of above-ground biomass (AGB) of C. endlicheri and C. glaucophylla (as measured by diameter at breast height (DBH) and dispersion) and the evenness of the species distribution was undertaken. This was done to further dissect the effect of Callitris AGB on species density (richness per quadrat) of native and introduced species and on broad life-form groupings. Other landscape features such as altitude, physiography, drainage and soil depth were also included in analyses. C. endlicheri and C. glaucophylla grow in different biophysical locations in most instances and this was reflected in the results of the study. No level of AGB or clumping of C. endlicheri was found to affect species density of native or introduced taxa or the distribution of life-forms. Increasing AGB of C. glaucophylla had a positive effect on native species density. The species density of introduced taxa was also increased with an increase in C. glaucophylla AGB. The distribution of life-forms was significantly affected by an increase in Callitris AGB with a decrease in trees, shrubby taxa and hemi-parasites, although herbaceous species had a concomitant increase in number. There is no reason to thin dense Callitris stands to increase local species richness. However, because the distribution of life-form types is significantly affected by C. glaucophylla, there is a need to understand what is occurring in species replacements and what landscape mosaic of structural types is required for this species. It is likely that dense stands of Callitris are important, along with a variety of stand densities so as to maintain the highest regional diversity.

2019 ◽  
Vol 36 (1) ◽  
pp. 6-12 ◽  
Author(s):  
Sarah Rosane M. C. Fadini ◽  
Reinaldo I. Barbosa ◽  
Rafael Rode ◽  
Viviane Corrêa ◽  
Rodrigo F. Fadini

AbstractMistletoes are considered keystone species on woodlands and savannas worldwide, providing a food resource for a diversified fauna, as well as a nutrient-enriched litter. Infections can be large (∼1–3 m) and, in some parts of the Amazonian savannas, parasitize up to 70% of hosts locally. Despite these facts, biomass of mistletoes is rarely investigated. Here we constructed allometric models to predict the biomass stock of the shrubby mistletoe Psittacanthus plagiophyllus in an Amazonian savanna. In addition, we determined whether host size could be used as a proxy for mistletoe biomass. Finally, we compared the biomass of mistletoes with that of trees, to evaluate their relative importance. We have shown that: (1) biomass of leaves (46.1% ± 13.5%) are as important as of stems (47.8% ± 13.5%), and relative contribution of stems increases as plant grows; (2) the model including width, breadth and vertical depth was the best (SE = 0.39, R2 = 0.9) for predicting individual mistletoe biomass; (3) mistletoe load and biomass per host had a positive, but weak (R2 = 0.11 and 0.09, respectively), relationship with host size, and thus such host information is a poor predictor of mistletoe biomass; and (4) in comparison with trees, mistletoes constituted less than 0.15% (0.5–22 kg ha−1) of the total above-ground biomass, suggesting that this life-form is irrelevant to the local biomass stock despite its unequivocal biological importance.


2019 ◽  
Author(s):  
M Itani ◽  
M. Al Zein ◽  
N. Nasralla ◽  
S. N. Talhouk

AbstractUrban plant habitats have become primary drivers of species interactions. They consist of managed vegetation and spontaneous assemblages of native, naturalized, ornamental garden escapes, and invasive species. Our objective was to define urban habitat analogs for a plant species of conservation interest, Matthiola crassifolia, which has persisted in varying abundance in the Mediterranean city of Beirut.We adopted a stepwise method that integrates two vegetation assessments, floristics, and physiognomy. We placed seventy-eight quadrats (1m x 1m) in 12 study sites following a deliberate biased method to capture habitat diversity. In every quadrat, we performed taxonomic identification and recorded life form of each species. We pooled species that shared the same life form into categories and estimated area cover for each of these life forms. We performed TWINSPAN analysis on floristic data to identify species positively associated with M. crassifolia, and on life forms, to determine plant assemblages that promote optimal M. crassifolia representation. We then combined findings from both analyses to generate a description of urban habitat analogs suitable for M. crassifolia.The results revealed that urban habitat analogs favorable to M. crassifolia include green spaces dominated by palms, low-lying succulents, or by shrubs with scale-like leaves. On the other hand, spaces dominated by turf grass, canopy trees, or vegetation that produces significant litter were not favorable to M. crassifolia’s persistence. Based on these findings, we generated a plant palette of native and non-native species to design urban habitat analogs favorable to the persistence of M. crassifolia.Synthesis and applicationsThe application of this method can inform planting designs that yield suitable habitats for plants of conservation interest. It can also guide landscape management plans that seek to create or modify green spaces to optimize growing conditions for species of conservation interest. Depending on sites, and based on the information generated by the stepwise method, designers and managers may decide to exclude life forms of native or non-native species that do not support the growth of a species of conservation interest, or they may create an artificial habitat that is conducive to its persistence.


2020 ◽  
Vol 153 (3) ◽  
pp. 373-389
Author(s):  
Farzaneh Bordbar ◽  
Pierre Meerts

Background and aims – This work provides the first pattern analysis of the alien flora of the Democratic Republic of the Congo (D.R. Congo), using Asteraceae and Fabaceae as a case study. Methods – Based on herbarium collections, existing databases, and literature data, a database of 38 alien species of Asteraceae and 79 alien species of Fabaceae has been assembled. Patterns in the introduction pathway, phylogeny, life form, morpho-functional traits, geographic origin, and occurrence in D.R. Congo are explored. Key results – America is the main source continent in both families, but Asia is also an important donor of Fabaceae. Taxonomic spectrum discrepancies between the alien and the native flora reflect the continent of origin. Sixty-six percent of alien Asteraceae have been accidentally introduced, most of which being annual weeds of disturbed soil. In contrast, 90% of alien Fabaceae have been deliberately introduced for forestry, agriculture, or environmental purposes, most of which being phanerophytes. Traits were compared between pairs of congeneric alien and native species. For Asteraceae, a sharp discrepancy was found in the life form spectrum (aliens: mostly therophytes; natives: phanerophytes). For Fabaceae, alien species had larger leaves and larger pods compared to their native congeners. The number of specimens in collections was positively correlated with the time since the date of first collection for both families. The Guineo-Congolian region has the highest number of alien Fabaceae, while alien Asteraceae are overrepresented in the Zambezian region.Conclusions – Contrasting patterns between alien Asteraceae and Fabaceae in the flora of D.R. Congo in terms of life forms, trait divergence compared to the native flora, and occurrence, reflect the divergent biological attributes and relations to humans of the two families. The striking discrepancies between the two families call for analyses of patterns of alien flora at family level and warn against global generalisations.


Author(s):  
Ramesh Kumar ◽  
R.S. Yadav ◽  
N.D. Yadava ◽  
Amit Kumawat ◽  
Vinay Nangia ◽  
...  

The study on “Evaluation of Cropsyst model for yield and water productivity of clusterbean” was conducted on farmers field during kharif 2012 at village Mainawali in Hanumangarh district of Rajasthan. The soils of the area are alluvial and calcareous in nature formed under arid and semi arid climate. The soils of site are brown to greyish brown and dark grey in colour, besides being calcareous and slightly alkaline in reaction having 67.7, 11.1 and 21.0 % of sand, clay and silt, respectively in 0-15 cm soil depth with pH 8.09 and low soil organic matter content. The simulate yield of clusterbean were closer to the observed clusterbean yield. Simulations of early clusterbean above ground biomass development matched the field data reasonably well. Final above ground biomass, however, was over estimated by the model. The total water applied in clusterbean was 405.8 mm out of this 326.7 mm consumed in ET. Thus, ET constituted 81% of total water applied and deep drainage constituted 13% and rest 6% stored as residual soil moisture.


2020 ◽  
Vol 13 (5) ◽  
pp. 589-600
Author(s):  
Maurício Cruz Mantoani ◽  
Alberto Benavent González ◽  
Leopoldo García Sancho ◽  
Bruce Arthur Osborne

Abstract Aims Gunnera tinctoria is an unusual N-fixing plant species that has become invasive worldwide, generally in environments with a low evaporative demand and/or high rainfall. Amongst the many mechanisms that may explain its success as an introduced species, a contrasting phenology could be important but this may depend on an ability to grow and utilize nutrients under sub-optimal conditions. We examined whether G. tinctoria has an advantage in terms of a contrasting phenology and N-fixing capability, in comparisons with Juncus effusus, the native species most impacted by G. tinctoria invasions. Methods We made phenological assessments on a weekly or bi-weekly basis on long-established populations on Achill Island, Ireland, during 2016–2017. Data on leaf and inflorescence number, total leaf area, light interception and above-ground biomass were collected alongside measurements of soil temperature, moisture and oxidation–reduction potential. The significance of N-fixing ability for supporting seasonal growth was assessed using δ 15N isotopic assessments, together with in situ acetylene reduction measurements. Important Findings The timing of the initiation of growth of G. tinctoria and J. effusus varied between 2016 and 2017, with the earlier emergence and expansion of leaves of G. tinctoria, and the largest above-ground biomass associated with higher water availability. The early growth of G. tinctoria was dependent on preformed structures, with maximum canopy development occurring in late May, prior to that of J. effusus. Whilst N-fixation was observed in March, this made a more significant contribution to growth during the later stages of canopy development. Based on δ 15N isotopic analyses, early growth was predominantly associated with N-remobilization from the rhizomes, whilst seedlings were largely reliant on N-fixation. This emphasizes the importance of nutrient mobilization for early growth and shows that the importance of an N-fixing capability may vary developmentally, as well as during different stages of the invasion process.


2013 ◽  
Vol 36 (1) ◽  
pp. 9-16
Author(s):  
V. Rao ◽  
K. Prasad ◽  
D. Veeranjaneyulu ◽  
P. Priyadarsini ◽  
Boyina Rao

The present study aimed to estimate above-ground biomass and carbon stocks of different life forms in tropical dry and moist deciduous forests of Nallamalais, one of the centers of plant diversity of India, located in central part of the Eastern Ghats. The present study used a non-destructive method of biomass estimation. From the sampled inventory it is found that the dry deciduous vegetation with 114 species comprising a total of 1737 tree individuals with a mean basal area of 16.37±9.12 m2 ha-1, 61.52±41.66 Mg ha-1 (Mega gram=106 g) above-ground biomass and 26.83±15.69 Mg ha-1 carbon, the moist deciduous vegetation with 115 species, comprising 1431 tree individuals with a mean basal area of 29.78±4.83 m2 ha-1, contributing 110.37±26.12 Mg ha-1 above-ground biomass and 52.24±12.48 Mg ha-1 carbon. It is revealed that the moist deciduous forests are more efficient in terms of sequestering atmospheric carbon.


1963 ◽  
Vol 41 (10) ◽  
pp. 1425-1437 ◽  
Author(s):  
S. C. Fabius LeBlanc

The life-forms of the flowering plants and vascular cryptogams of the flora of Mount Yamaska, Quebec, are listed according to the system developed by C. Raunkiaer. Four life-form spectra have been established. Spectra including vascular cryptogams do not vary significantly from those without vascular cryptogams; spectra including both naturalized and native species vary somewhat from those including native species only. The life-form spectrum of native and naturalized phanerogams is compared with similar spectra from other localities in eastern North America.


2017 ◽  
Vol 23 (2) ◽  
Author(s):  
AFSHAN ANJUM BABA ◽  
SYED NASEEM UL-ZAFAR GEELANI ◽  
ISHRAT SALEEM ◽  
MOHIT HUSAIN ◽  
PERVEZ AHMAD KHAN ◽  
...  

The plant biomass for protected areas was maximum in summer (1221.56 g/m2) and minimum in winter (290.62 g/m2) as against grazed areas having maximum value 590.81 g/m2 in autumn and minimum 183.75 g/m2 in winter. Study revealed that at Protected site (Kanidajan) the above ground biomass ranged was from a minimum (1.11 t ha-1) in the spring season to a maximum (4.58 t ha-1) in the summer season while at Grazed site (Yousmarag), the aboveground biomass varied from a minimum (0.54 t ha-1) in the spring season to a maximum of 1.48 t ha-1 in summer seasonandat Seed sown site (Badipora), the lowest value of aboveground biomass obtained was 4.46 t ha-1 in spring while as the highest (7.98 t ha-1) was obtained in summer.


2016 ◽  
Vol 13 (11) ◽  
pp. 3343-3357 ◽  
Author(s):  
Zun Yin ◽  
Stefan C. Dekker ◽  
Bart J. J. M. van den Hurk ◽  
Henk A. Dijkstra

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.


2021 ◽  
Vol 21 ◽  
pp. 100462
Author(s):  
Sadhana Yadav ◽  
Hitendra Padalia ◽  
Sanjiv K. Sinha ◽  
Ritika Srinet ◽  
Prakash Chauhan

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