Use of growth characteristics for predicting plant age of three obligate-seeder Proteaceae species

2005 ◽  
Vol 53 (2) ◽  
pp. 101 ◽  
Author(s):  
Meaghan E. Jenkins ◽  
David A. Morrison ◽  
Tony D. Auld
Keyword(s):  
Management Strategies ◽  
Growth Characteristics ◽  
Plant Age ◽  
Large Spatial Scale ◽  
Obligate Seeder ◽  
Canopy Area ◽  
Banksia Ericifolia ◽  
Volume Estimates ◽  
Age Estimates ◽  
Area And Volume

We tested the ability to predict plant (and hence population) age for three fire-sensitive obligate-seeder Proteaceae species (Banksia ericifolia, Banksia marginata and Petrophile pulchella) in the heath and woodland vegetation of the Sydney region. To do this we sampled the number of growth whorls, as well as other growth characteristics (stem girth and height measurements, and canopy area and volume estimates), in areas of known time since last fire (TSLF). The average number of growth whorls was a very good predictor of plant age for both Banksia species (R2 = 98%, 99%), but this needed to be corrected for linear underestimation in P. pulchella (R2 = 92%). This technique could successfully be applied to these species in similar habitats across a large spatial scale, and so this information can be used to determine the age of a population in areas of unknown TSLF. A sample size of 15 plants was sufficient for accurate age estimates of all species; however, better estimates of TSLF for a particular plant community were obtained when estimates from two or more of the species were combined. We thus provide empirical evidence for the validity and accuracy of the growth-whorl technique for predicting plant age and hence TSLF. This information will assist in informing the development of appropriate management strategies for plants in relation to fire. Of the other growth characteristics studied, stem girth was the most reliable predictor; however, in general these other characteristics had wide confidence intervals on the predictions for sites greater than 10 years TSLF, owing to a non-linear relationship with age.

scholarly journals Estimating seed bank accumulation and dynamics in three obligate-seeder Proteaceae species

2014 ◽  
Author(s):  
Meaghan E. Jenkins ◽  
David Morrison ◽  
Tony D. Auld
Keyword(s):  
Seed Bank ◽  
Significant Variation ◽  
Reproductive Strategies ◽  
Plant Age ◽  
Obligate Seeder ◽  
Seed Bank Dynamics ◽  
Banksia Ericifolia ◽  
Regeneration Strategies ◽  
In Fire ◽  
Number Of Seeds

The seed bank dynamics of the three co-occurring obligate-seeder (i.e. fire-sensitive) Proteaceae species, Banksia ericifolia, Banksia marginata and Petrophile pulchella, were examined at sites of varying time since the most recent fire (i.e. plant age) in the Sydney region. Significant variation among species was found in the number of cones produced, the position of the cones within the canopy, the percentage of barren cones produced (Banksia species only), the number of follicles/bracts produced per cone, and the number of seeds lost/released due to spontaneous fruit rupture. Thus, three different regeneration strategies were observed, highlighting the variation in reproductive strategies of co-occurring Proteaceae species. Ultimately, B. marginata potentially accumulated a seed bank of ~3000 seeds per plant after 20 years, with ~1500 seeds per plant for P. pulchella and ~500 for B. ericifolia. Based on these data, B. marginata and B. ericifolia require a minimum fire-free period of 8–10 years, with 7–8 years for P. pulchella, to allow for an adequate seed bank to accumulate and thus ensure local persistence of these species in fire-prone habitats.

scholarly journals Cycle pruning programmed on the grain yield of arabica coffee

2019 ◽  
Vol 43 ◽  
Author(s):  
Diego Corona Baitelle ◽  
Abraão Carlos Verdin Filho ◽  
Sílvio de Jesus Freitas ◽  
Guilherme Bessa Miranda ◽  
Henrique Duarte Vieira ◽  
...  
Keyword(s):  
Block Design ◽  
Management Strategies ◽  
Production Capacity ◽  
Additional Treatment ◽  
Control Treatment ◽  
Arabica Coffee ◽  
Randomized Block Design ◽  
Canopy Area ◽  
Plagiotropic Branches ◽  
Productive Development

ABSTRACT The cycle pruning programmed is a reinvigoration technique widely employed in Conilon coffee. This strategy may also be adopted for Arabica coffee to increase its crop longevity and yield. In this scenario, the present study proposes to examine the influence of the cycle pruning programmed on the vegetative and productive development of Arabica coffee. The experiment was developed in the field as a randomized-block design with four replicates. Treatments were tested in a 4 × 2 factorial arrangement consisting of four stem densities (4000, 8000, 12000 or 16000 stems ha-1) and two management strategies for the removal of plagiotropic branches (annual or biennial removal of branches which had reached 70% or more of their production capacity). For some variables, the treatments were organized as a 4 × 2 × 2 factorial arrangement in which the last factor corresponded to two regions of data collection in the plant (upper or lower). For all factorial arrangements, an additional treatment (control) was employed corresponding to traditional pruning (recepa). Annual or biennial removal of plagiotropic branches which had attained 70% or more of their production capacity can be adopted with no losses to crop yield. The cycle pruning programmed improves the distribution of branches, increases canopy area and prevents the occurrence of the “naked neck” phenomenon, observed in control treatment. Additionally, it provides better agronomic and productive performance; therefore, it can be used as a substitute for recepa.

Great longevity of speckled hind (Epinephelus drummondhayi), a deep-water grouper, with novel use of postbomb radiocarbon dating in the Gulf of Mexico

2013 ◽  
Vol 70 (8) ◽  
pp. 1131-1140 ◽  
Author(s):  
Allen H. Andrews ◽  
Beverly K. Barnett ◽  
Robert J. Allman ◽  
Ryan P. Moyer ◽  
Hannah D. Trowbridge
Keyword(s):  
Gulf Of Mexico ◽  
Deep Water ◽  
Radiocarbon Dating ◽  
Early Growth ◽  
Economic Importance ◽  
Growth Characteristics ◽  
Adult Age ◽  
Bomb Radiocarbon ◽  
Growth Zones ◽  
Age Estimates

Growth characteristics are poorly understood for speckled hind (Epinephelus drummondhayi), a tropical deep-water grouper of economic importance that is considered overfished. Age has been validated for early growth, but the validity of adult age estimates is unknown. A few studies of growth zones in otoliths have revealed maximum age estimates of 15–35 years, which have been uncritically assumed as longevity. To answer questions about adult age, bomb radiocarbon dating was used to provide validated age estimates. A novel aspect of this study was use of the postbomb radiocarbon decline period (ca. 1980–2004) to age younger fish, an approach that was validated with known-age otoliths. Bomb radiocarbon dating provided valid length-at-age estimates ranging from ∼5 years to more than 45 years. Age was unexpectedly greater than previous estimates for more than half the fish used in this study, and longevity may approach 60–80 years. This study extends the utility of bomb radiocarbon dating by more than 20 years and adds to the growing perspective that deep-water tropical fishes can be long-lived.

scholarly journals Effects of Temperature, Relative Humidity, and Plant Age on Bacterial Disease of Onion Plants

2019 ◽  
Vol 20 (4) ◽  
pp. 200-206
Author(s):  
Kim E. Tho ◽  
Elizabeth Brisco-McCann ◽  
Prissana Wiriyajitsomboon ◽  
Mary K. Hausbeck
Keyword(s):  
Relative Humidity ◽  
Management Strategies ◽  
Bacterial Pathogen ◽  
Plant Age ◽  
Effect Of Temperature ◽  
Bacterial Disease ◽  
Disease Symptoms ◽  
Foliar Disease ◽  
Progress Curve ◽  
Effects Of Temperature

Foliar disease of onion in Michigan, caused by Pantoea agglomerans, Pantoea ananatis, or Enterobacter cowanii, has recently become a concern to producers. The objective of this study was to determine the effect of temperature, relative humidity (RH), and plant age in growth chamber and greenhouse experiments on onion plants inoculated with each pathogen. A significant level of disease resulted from each pathogen at 25 to 30°C, with strong positive associations detected using regression analysis between the area under the disease progress curve (AUDPC) and temperature. RH also significantly influenced symptom development. Foliar disease symptoms developed sooner and were more severe when RH was high (80 to 100%) but was limited at RH < 60%. Significant positive associations between RH and AUDPC, as described by linear regression, were also detected. When 6- to 14-week-old plants were inoculated with each bacterial pathogen, susceptibility increased significantly with age. These results provide insight into the epidemiology of P. agglomerans, P. ananatis, and E. cowanii bacterial pathogens of onions in Michigan and can assist in the development and timing of management strategies.

scholarly journals Radio-echo sounding and ice volume estimates of western Nordenskiöld Land glaciers, Svalbard

2013 ◽  
Vol 54 (64) ◽  
pp. 211-217 ◽  
Author(s):  
A. Martín-Español ◽  
E.V. Vasilenko ◽  
F.J. Navarro ◽  
J. Otero ◽  
J.J. Lapazaran ◽  
...  
Keyword(s):  
Reliable Estimate ◽  
Ice Thickness ◽  
Potential Contribution ◽  
Ice Volume ◽  
Ongoing Work ◽  
Radio Echo Sounding ◽  
Field Campaigns ◽  
The Individual ◽  
Volume Estimates ◽  
Area And Volume

Abstract As part of ongoing work to obtain a reliable estimate of the total ice volume of Svalbard glaciers and their potential contribution to sea-level rise, we present here volume calculations, with detailed error estimates, for ten glaciers on western Nordenskiöld Land, central Spitsbergen, Svalbard. The volume estimates are based upon a dense net of GPR-retrieved ice thickness data collected over several field campaigns spanning the period 1999-2012. The total area and volume of the ensemble are 116.06 ± 4.53 km2 and 10.439 ±0.373 km3, respectively, while the individual areas, volumes and average ice thickness lie within 2.6-50.4 km2, 0.08-5.54 km3 and 29-108 m, respectively. Volume/area scaling relationships overestimate the total volume of these glaciers by up to 35% with respect to our calculation. On the basis of the pattern of scattering in the radargrams, we also analyse the hydrothermal structure of these glaciers. Nine of the ten are polythermal, while only one is entirely cold.

scholarly journals Growth and Volume Estimates of Teak (Tectona grandis Linn F.) in Kanya Forest Plantation, Kebbi State, Nigeria

2019 ◽  
pp. 1-10
Author(s):  
A. Dantani ◽  
S. B. Shamaki ◽  
M. A. Gupa ◽  
A. I. Zagga ◽  
B. Abubakar ◽  
...  
Keyword(s):  
Basal Area ◽  
Tectona Grandis ◽  
Growth And Yield ◽  
Forest Plantation ◽  
Scatter Plots ◽  
Volume Production ◽  
Yield Values ◽  
Volume Estimates ◽  
Negative Relationships ◽  
Area And Volume

This study was conducted in order to estimate growth and volume production of Teak (Tectona grandis) in Kanya Forest Plantation, Nigeria. The plantation was divided in to six strata-based age classes (A=38, B=37, C=36, D=35, E=34, F=28, years). Five plots were randomly selected from each stratum. Trees within each plot were enumerated and measured. Variables measured include total height, diameter at the base, middle, top, and diameter at the breast height were taken from 30 temporary sampled plots of 25x25 m approximately from the center, 180 dominant trees were selected from 712 trees. Descriptive statistic was used to summarize the results while inferential statistic (correlation) was used to establish relationship growth and yield variables. Basal area and volume of sampled trees were computed using Excel as well as scatter plots, correlation analysis was achieved using SPSS statistical package version 20. The results of growth and yield values obtained from the dominant trees are (B=249.312 m3/ha, D=196.128 m3/ha, F=134.976 m3/ha, C=119.328 m3/ha, E=100.320 m3/ ha and A=86.976 m3/ha). The results showed that B was (37 years) the best and A (38 years) was the poorest. The results of correlation showed positive relationships with most of the tree growth and yield characteristics but negative relationships exist between age and some parameters that is to say as the age increases those parameters are decreasing.

Lake Eyre golden perch (Macquaria sp.) spawning and recruitment is enhanced by flow events in the hydrologically variable rivers of Lake Eyre Basin, Australia

2015 ◽  
Vol 66 (9) ◽  
pp. 822 ◽  
Author(s):  
B. J. Cockayne ◽  
D. Sternberg ◽  
D. W. Schmarr ◽  
A. W. Duguid ◽  
R. Mathwin
Keyword(s):  
Channel Flow ◽  
River Flow ◽  
Arid Zone ◽  
Close Association ◽  
Management Strategies ◽  
Low Flow ◽  
Class Strength ◽  
Floodplain Inundation ◽  
Semi Arid ◽  
Age Estimates

Understanding the links between fish recruitment and riverine flows is integral for setting priorities for river-management strategies, particularly in hydrologically variable and unpredictable arid and semi-arid zone rivers. In the present study, we used daily and annual otolith age estimates to identify relationships between riverine flow and spawning and recruitment of Lake Eyre golden perch (Macquaria sp.); an endemic fish of the Lake Eyre Basin, central Australia. We found a close association between Lake Eyre golden perch spawning and periods of increased river flow, with most of spawning occurring 0–35 days after the start of these flow events. Spawning occurred throughout the year but was commonly observed during the first flow events proceeding consecutive months of no-flow when water temperatures exceeded 26°C. Spawning was not dependent on floodplain inundation, with most spawning occurring during within-channel flow events. Annual average year-class strength was related to the number of flow events per year, but not total annual discharge, or the number of low-flow days per year. These results highlight the importance of natural within-channel flow patterns to Lake Eyre golden perch spawning and recruitment and demonstrate the importance of maintaining the natural flow regime of Australia’s arid- and semi-arid-zone rivers.

scholarly journals Non-genetic effects on growth characteristics of Brahman cattle

2015 ◽  
pp. 4427-4435 ◽  
Author(s):  
Nicacia Hernández-Hernández ◽  
Juan Martínez-González ◽  
Gaspar Parra-racamonte ◽  
Martín Ibarra-Hinojosa ◽  
Florencio Briones-Encinia ◽  
...  
Keyword(s):  
Birth Weight ◽  
Rainy Season ◽  
Genetic Factors ◽  
Management Strategies ◽  
Growth Characteristics ◽  
Season Of Birth ◽  
Birth Season ◽  
Brahman Cattle ◽  
Productive System ◽  
One Year

Objective. To determine how some non-genetic factors influence weights at birth (BW), weaning (WW) and yearling (YW) of Brahman calves. Materials and methods. Data corresponding to 58257, 57045 and 40364 for BW, WW and YW, respectively, were analyzed. The models included the effects of year and season of birth and sex, and were considered simple interactions. Results. All effects were significant (p<0.05) for BW, WW and YW. Only the season of birth didn’t have a significant effect (p>0.05) on WW. The average general BW, WW and YW were 32±3.2, 188±37.7 and 291±56.8 kg, respectively. Variables evaluated that take into account the year of birth show a trend to increase weight each year. In relation to the birth season on BW and YW, it was observed that calves born during the rainy season were heavier than those born during the dry season. Similarly, male calves were heavier than females at birth, weaning and one year of age. The effects of the analyzed interactions were significant (p<0.05) for the three variables, except for the season of birth per sex interaction, which did not have a significant effect (p>0.05) for BW and WW. Conclusions. The studied non-genetic factors were important and should be taken into account in management strategies when striving to increase the efficiency of the productive system. Key words: Zebu, birth weight, weaning weight, year weight. (Source: AIMS)

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