Needle demography and growth pattern of Corsican pine

1982 ◽  
Vol 60 (2) ◽  
pp. 105-116 ◽  
Author(s):  
Lucie Maillette
Keyword(s):  
Frequency Distribution ◽  
Growth Pattern ◽  
Apical Dominance ◽  
Pine Needles ◽  
Tree Age ◽  
Climatic Variations ◽  
Activity Schedule ◽  
Log Normal ◽  
Needle Senescence ◽  
Different Parts

A study of the demography of the needles and the growth pattern of Corsican pine is presented in relation to other studies of foliage dynamics. The construction of life tables is explained and applied to populations of Corsican pine needles. Needles from different trees as well as from different parts of trees had different survivorship. Leader needles had a much lower survivorship than all other needles. The frequency distribution of shoot lengths was log-normal, with the leader as the longest shoot. Climatic variations, tree age, apical dominance, and growth pattern appeared to be some of the factors involved in needle survivorship. Possible causes of needle senescence are considered with respect to an "activity schedule" derived from the work of other authors.

Assessment of sugar maple health based on basal area growth pattern

2003 ◽  
Vol 33 (11) ◽  
pp. 2074-2080 ◽  
Author(s):  
Louis Duchesne ◽  
Rock Ouimet ◽  
Claude Morneau
Keyword(s):  
Growth Pattern ◽  
Acer Saccharum ◽  
Radial Growth ◽  
Sugar Maple ◽  
Basal Area ◽  
Tree Age ◽  
Tree Health ◽  
Health Decline ◽  
Area Growth ◽  
Natural Range

The first tree health decline symptoms usually observed are foliar deficiency symptoms, foliage loss, and dieback. To improve the subjective nature and unspecificity of these assessments, we examined sugar maple (Acer saccharum Marsh.) radial growth and health to develop an indicator of sugar maple tree health status based on radial growth pattern. We used the basal area increment (BAI) of 328 tree-ring collections from 16 sites located in southern Quebec, throughout the sugarbush natural range, that were categorized by defoliation class. BAI of trees with decline symptoms was significantly lower than that of healthy trees in 9 of the 16 stands. BAI trends since 1955 showed an inverse relationship with tree decline class measured in 1989, irrespective of tree age. The results indicate that declining trees in these stands have not recovered based on BAI. They also suggest that the decrease in slope of BAI predated the observed symptoms of sugar maple decline by at least one decade. Results suggest that sugar maple vigor and health can be assessed by measuring tree's BAI trend, an indicator that may be useful for the diagnosis of sugar maple health and status years before the appearance of visible canopy symptoms.

scholarly journals Pola pertumbuhan dan faktor kondisi ikan lemeduk (Barbodes schwanenfeldii) di Sungai Belumai Deli Serdang Provinsi Sumatera Utara

2017 ◽  
Vol 4 (1) ◽  
pp. 8
Author(s):  
Siti Aisyah ◽  
Darma Bakti ◽  
Desrita Desrita
Keyword(s):  
Frequency Distribution ◽  
Growth Pattern ◽  
Condition Factor ◽  
Length Frequency Distribution ◽  
Length Frequency ◽  
Growth Coefficient ◽  
Weight Relationship

Penelitian ini dilakukan di Sungai Belumai Kabupaten Deli Serdang Provinsi Sumatera Utara pada Bulan Mei dan juni 2014 di empat lokasi yang berbeda dengan menggunakan metode sensus. Tujuan dari penelitian ini untuk mengetahui aspek pertumbuhan (sebaran frekuensi panjang, hubungan panjang bobot, faktor kondisi dan koefisien pertumbuhan). Jumlah ikan lemeduk yang tertangkap adalah 55 ekor. Hasil penelitian menggambarkan bahwa populasi ikan didominasi oleh sebaran ukuran kelas panjang 174-194 mm. Hasil hubungan panjang berat menunjukkan bahwa pola pertumbuhan ikan bersifat allometrik negatif (b=2,565) dimana pertambahan panjang lebih cepat dibandingkan pertambahan berat. Nilai faktor kondisi ikan lemeduk (Barbodes schwanenfeldii) berkisar 0,946-1,059.This research was done in Belumai River Deli Serdang District North Sumatera Province. This research was conducted in May until June 2014 in four different locations by using census method. The purpose of this research is to know the aspect of growt (length frequency distribution, length-weight relationship, condition factor and growth coefficient). The number of lemeduk fish which caught were 55 fish. Result shown that the population is dominate by length frequency distribution 174-194 mm. Result length-weight relationship shown that growth pattern was allometric negative (b=2,565) where the length is faster growth than the weight. The condition factor of lemeduk fish was around 0,946-1,059.

scholarly journals DISTRIBUSI UKURAN IKAN TERI (Stolephorus sp) YANG DITANGKAP PADA PERIKANAN BAGAN TANCAP DI MUARA SUNGSANG SUMATERA SELATAN (Size Distribution of Anchovy (Stolephorus sp.) Caught in Stationary Liftnets at Sungsang Estuary South Sumatera)

2016 ◽  
Vol 7 (2) ◽  
pp. 161
Author(s):  
. Fauziyah ◽  
. Hadi ◽  
Khairul Saleh ◽  
Freddy Supriyadi
Keyword(s):  
Frequency Distribution ◽  
Growth Pattern ◽  
Growth Form ◽  
Condition Factor ◽  
Size Structure ◽  
Length Frequency Distribution ◽  
Fishing Pressure ◽  
Length Frequency ◽  
Relative Condition Factor ◽  
Factor Frequency

<p><strong>ABSTRACT<br /> </strong><br />The anchovy  (Stolephorus sp.)  in  Muara  Sungsang  estuary South Sumatera  are  generally caught by stationary liftnet. Morphometric studies are essential to determine the growth form and growth rate of species, which is  very much important for proper  utilization  and management of the population of the species. This study aimed to determine the size structure and growth pattern of the  anchovy  caught  by  stationary  liftnet.  The   size  structure,  length -weight  relationship  and  the condition factor  of  anchovy were computed.  The anchovy samples were taken  in July 2013 (750 samples) and September 2013 (1950 samples).    Results  showed  that the population of anchovy was  dominated by length frequency distribution  of  65 mm during study on July 2013 and 75 mm during  study  on  September  2013.  Both  populations  were  dominated  by  weight  frequency distribution 2 gram.  The anchovy that caught on September 2013 were more allowable catch than on July 2013. The growth pattern of anchovy was negative allometric. The relative condition factor (Kn)  value  in  September  2013  was  higher  than  in  July  2013.  It  indicated  that  the  environmental conditions  at  Muara  Sungsang  estuary  are  suitable  for  growth  of  anchovy’s  and  still  safe  from fishing pressure.</p><p>Keywords: allometric, anchovy, condition factor, frequency distribution</p><p> <strong><br />ABSTRAK</strong></p><p>Ikan  Teri  (Stolephorus  sp.)  di  Muara  Sungsang  Sumatera  Selatan  umumnya  ditangkap menggunakan bagan tancap. Studi morfometrik berguna untuk menentukan bentuk pertumbuhan dan laju pertumbuhan spesies. Hal ini berguna untuk manajemen populasi dan sebagai informasi tentang stok atau kondisi organisme. Disamping itu, sebagai dasar dalam upaya pengelolaan dan pemanfaatan  ikan  teri  di  masa  akan  datang.  Penelitian  ini  bertujuan  untuk  mengetahui  struktur ukuran dan pola pertumbuhan ikan teri hasil tangkapan bagan tancap. Data ikan teri didapatkan pada  bulan  Juli  2013  (750  sampel)  dan  September  2013  (1950  sampel).  Hasil  penelitian menunjukkan bahwa populasi ikan teri didominasi oleh distribusi frekuensi panjang 65 mm pada bulan Juli 2013 dan 75 mm pada bulan September 2013. Distribusi frekuensi berat teri pada kedua bulan tersebut sama yaitu 2 gram. Penangkapan ikan teri pada bulan September 2013 lebih layak tangkap  dibandingkan  pada  bulan  Juli  2013.  Pertumbuhan  ikan  teri  bersifat  negative  allometric. Nilai Faktor kondisi (Kn) pada bulan September 2013 lebih tinggi daripada bulan Juli 2013. Hal ini mengindikasikan bahwa kondisi  lingkungan Muara Sungsang cocok untuk pertumbuhan ikan teri dan masih aman dari tekanan aktivitas penangkapan.</p><p>Kata kunci: allometrik, teri, faktor kondisi,distribusi frekuensi</p>

scholarly journals Variability and change in the hydro-climate and water resources of Iran over a recent 30-year period

2020 ◽  
Vol 10 (1) ◽  
Author(s):  
Davood Moshir Panahi ◽  
Zahra Kalantari ◽  
Navid Ghajarnia ◽  
Samaneh Seifollahi-Aghmiuni ◽  
Georgia Destouni
Keyword(s):  
Water Storage ◽  
Calculated Data ◽  
Irrigated Agriculture ◽  
Groundwater Depletion ◽  
World Region ◽  
Climatic Variations ◽  
The World ◽  
Storage Change ◽  
Semi Arid ◽  
Different Parts

AbstractComprehensive assessment of hydro-climatic variations and change trends is essential for understanding, mitigating, and adapting to key water resource changes in different parts of the world. We performed such an assessment on Iran, as representative of an arid/semi-arid and geopolitically important world region. We acquired and calculated data time series of surface temperature (T), precipitation (P), runoff (R), evapotranspiration (ET), and water storage change (DS), to determine their status and changes in and among the 30 main hydrological basins in Iran over the period 1986–2016. From 1986–2000 to 2001–2016, the country warmed, P mostly decreased and R even more so, while water storage was depleted (DS < 0) and ET increased in some basins. Overall, the extra water provided from primarily groundwater depletion has fed and kept ET at levels beyond those sustained by the annually renewable water input from P. This indicates unsustainable use of water for maintaining and expanding human activities, such as irrigated agriculture, in this part of the world.

Relations between abundance, body size and species number in British birds and mammals

1996 ◽  
Vol 351 (1337) ◽  
pp. 265-278 ◽  
Keyword(s):  
Body Size ◽  
Frequency Distribution ◽  
Body Mass ◽  
Species Number ◽  
Metabolic Rates ◽  
Frequency Distributions ◽  
Migrant Birds ◽  
Log Normal ◽  
Normally Distributed

British birds and mammals are compared in terms of their frequency distributions of abundance and body mass and in respect of the relation between abundance and body mass. Body masses of non-flying mammals are greater than those of resident birds which are, in turn, heavier than migrants; bats are lightest. The frequency distribution of masses are close to log-Normal for each of these groups, though their variances and skews differ. Differences in mean abundances (which are log-Normally distributed) parallel those in body mass. In each group, abundance declines with body mass: the exponent of the relation is close to the value of —0.75 predicted by the ‘energetic equivalence’ rule though not significantly different from the value of — 1.0 predicted by the ‘biomass equivalence’ rule. At comparable masses, species of non-flying mammals are more abundant than resident birds, migrant birds and bats by approximately 45, 300 and 200 times, respectively. The similarity between birds and bats in this regard may be no more than coincidental but it may be related to ecological similarities related to flight. The metabolic rates of non-flying mammals may be generally lower than those of birds and bats but not sufficiently to account for their much greater abundances.

Global fire size distribution: from power law to log-normal

2016 ◽  
Vol 25 (4) ◽  
pp. 403 ◽  
Author(s):  
Stijn Hantson ◽  
Salvador Pueyo ◽  
Emilio Chuvieco
Keyword(s):  
Size Distribution ◽  
Frequency Distribution ◽  
Power Law ◽  
Likelihood Estimation ◽  
Fire Size ◽  
Chi Square ◽  
Size Frequency Distribution ◽  
Size Frequency ◽  
Fire Size Distribution ◽  
Log Normal

Wildland fires are one of the main alleged examples of Self-Organised Criticality (SOC), with simple SOC models resulting in the expectation of a power-law fire size frequency distribution. Here, we test whether fire size distributions systematically follow a power law and analyse their spatial variation for eight distinct areas over the globe. For each of the areas, we examine the fire size frequency distribution using two types of plots, maximum likelihood estimation and chi-square tests. Log-normal emerges as a suitable option to fit the fire size distribution in this variety of environments. In only two of eight areas was the power law (which is a particular case of the log-normal) not rejected. Notably, the two parameters of log-normal are related to each other, displaying a general linear relation, which extends to the sites that can be described with a power law. These results do not necessarily refute the SOC hypothesis, but reveal the presence of other processes that are, at least, modulating the outcome of SOC in some areas.

Frequency Distribution and Host-Parasite Relationships of Zschokkella Leptatherinae (Myxozoa: Myxiidae), a Parasite of Atherinid Fishes

1996 ◽  
Vol 44 (1) ◽  
pp. 97 ◽  
Author(s):  
XQ Su ◽  
RWG White
Keyword(s):  
Frequency Distribution ◽  
Fish Species ◽  
Parasite Infection ◽  
Normal Model ◽  
Intensity Of Infection ◽  
Host Parasite Relationship ◽  
Parasite Relationship ◽  
Log Normal ◽  
Host Parasite ◽  
Relationship Of

The frequency distribution and aspects of host-parasite relationship of the myxosporean Zschokkella leptatherinae Su and White (1995) in the hepatic ducts and gall bladder of two atherinid fishes, Atherinosoma microstoma (Gunther) and Leptatherina presbyteroides (Richardson), were studied from January 1990 to June 1992. In both fish species, the distribution of Z. leptatherinae fitted the log-normal model. The prevalence and intensity of infection did not vary seasonally. The infection of the parasite occurred more frequently in larger hosts in both fish species but no relationship existed either between the intensity of parasite infection and the size of fish or between the prevalence of parasite infection and sex of fish.

An analysis of size frequency distribution of oil and gas reserves of Western Canada

1969 ◽  
Vol 6 (2) ◽  
pp. 201-211 ◽  
Author(s):  
R. G. McCrossan
Keyword(s):  
Frequency Distribution ◽  
Oil And Gas ◽  
Sufficient Information ◽  
Western Canada ◽  
Size Frequency Distribution ◽  
Normal Distributions ◽  
Size Frequency ◽  
Log Normal ◽  
The Individual ◽  
Normally Distributed

Both the oil and gas reserves of Western Canada are log-normally distributed. If the total reserves are separated into groups made up of single types of occurrence, these all display log-normal distributions as well. The parameters of the distributions vary considerably for different groups of genetically related accumulations. Many of the distributions also appear to be heterogeneous, showing distinct bimodality. Several hypotheses can be offered to explain this. For instance, the reserves of the group of smaller sized pools may be under-estimated for lack of sufficient information; secondly, geologically unlike types of pools may be grouped together. If the former is the case, an estimate can be made of the additional oil and gas in aggregate that may be undeveloped in the smaller under-estimated pools. The degree of bimodality may also indicate the maturity of an exploration play. Other possibilities are also considered. The distribution curves for the total reserves show only a generalized picture and obscure the characteristics of the individual distributions of the several types of oil or gas accumulations.

Distribution of Self-Reported Alcohol Consumption in New Zealand, 1978–1979

1980 ◽  
Vol 47 (1) ◽  
pp. 159-170 ◽  
Author(s):  
Robert A. M. Gregson ◽  
Barrie G. Stacey
Keyword(s):  
Time Series ◽  
New Zealand ◽  
Alcohol Consumption ◽  
Frequency Distribution ◽  
National Survey ◽  
Recent History ◽  
Normal Frequency ◽  
Total Alcohol ◽  
History Of ◽  
Log Normal

The problem of estimating how much alcohol individuals actually drink is discussed with particular reference to the log-normal frequency distribution of alcohol consumption. It is then presented as being a problem of inference from the recent history of a time series. Following directly from this presentation, data obtained in a national survey of 10,000 New Zealand residents are analyzed (a) to yield the frequency distribution of estimated drinking rates; (b) to test whether this distribution is log-normal in form; and (c) to provide further information about the distribution of alcohol consumption. This analysis enabled us to account for almost the whole of the actual total alcohol consumption in New Zealand. The results are different from those expected on the basis of the uncorrected log-normal description of consumption.

Growth Responses of Musk and Plumeless Thistles (Carduus nutansandC. acanthoides) to Damage byTrichosirocalus horridus(Coleoptera: Curculionidae)

Weed Science ◽  
1985 ◽  
Vol 33 (1) ◽  
pp. 57-62 ◽  
Author(s):  
Bob Cartwright ◽  
Loke T. Kok
Keyword(s):  
Growth Pattern ◽  
Apical Dominance ◽  
Sublethal Effects ◽  
Plant Response ◽  
Growth Responses ◽  
Field Plot ◽  
Growing Conditions

Plant response studies were conducted from 1980 to 1982 under pasture and field plot conditions to determine the sublethal effects of the thistle rosette weevil [Trichosirocalus (Ceuthorynchidius) horridus(Panzer)] onCarduusthistles. Response to weevil damage was dependent upon thistle size and growing conditions. Damage byT. horridusdestroyed apical dominance, which altered the thistle growth pattern. Infested plants consistently produced more stems and a larger crown than uninfested thistles. Large thistles were stimulated by weevil damage, producing heavier stems and more heads. Small infested thistles developed more quickly than small uninfested thistles. Small and medium infested thistles were shorter and produced fewer seeds and heads than uninfested thistles. The extent of thistle reduction by this weevil will ultimately be determined by the conditions under which thistles grow.

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