Modelling probability of root disease center occurrence in northern Idaho forests

1982 ◽  
Vol 12 (4) ◽  
pp. 876-882 ◽  
Author(s):  
Ralph E. Williams ◽  
Michael A. Marsden
Keyword(s):  
Habitat Type ◽  
Root Disease ◽  
Center Frequency ◽  
Stand Age ◽  
Habitat Types ◽  
Disease Occurrence ◽  
Site Characteristics ◽  
Screening Algorithm ◽  
Northern Idaho ◽  
Data Screening

A data screening algorithm (SCREEN) identified stand age, average stand diameter, timber type, soil type, aspect, habitat type, and elevation as forest stand or site characteristics strongly associated with root-disease occurrence in northern Idaho forests. The logistic regression model was used to predict root disease center occurrence. A second algorithm (RISK) was used to compute the estimates for the coefficients and to test different prediction equations. On wet aspects, highest probability of root disease centers was found on soils with lowest year-round moisture availability. The reverse was true on dry aspects. Increased slope was associated with increased root disease. Root disease center frequency was inversely related to elevation and directly related to occurrence of Pseudotsugamenziesii (Mirb.) Franco and Abiesgrandis (Dougl.) Lindl. Expression of disease centers was maximum at 60–100 years of stand age on all habitat types. A habitat-type–age interaction was observed in oldest aged stands.

A system using aerial photography to estimate area of root disease centers in forests

1978 ◽  
Vol 8 (2) ◽  
pp. 214-219 ◽  
Author(s):  
Ralph E. Williams ◽  
C. D. Leaphart
Keyword(s):  
Large Scale ◽  
Habitat Type ◽  
Root Disease ◽  
Aerial Photographs ◽  
National Forest ◽  
Forest Land ◽  
Habitat Types ◽  
Coeur D'alene ◽  
Commercial Forest ◽  
Northern Idaho

The area of root disease centers on the Coeur d'Alene National Forest in northern Idaho was effectively estimated from large-scale color infrared aerial photographs. An estimated 5.1% (12 160.7 ha) of the commercial forest land was occupied by infection centers. Root disease centers were identified in 113 of 364 stands actually surveyed. Although most of these 113 stands were of the Tsugaheterophylla – Pachistimamyrsinites habitat type, the highest percentage of stands with root disease was found in the Abiesgrandis – Pachistimamyrsinites habitat type.Observations made during these studies suggest that occurrence of Pseudotsugamenziesii (Mirb.) Franco, Abiesgrandis (Dougl.) Lindl., or both in a stand is the most important factor in the expression of root disease centers. Accuracy of interpretation of photographs was 92%; incorrect interpretations were consistently associated with stands in the Abieslasiocarpa series of habitat types or with stands stocked with conifers tolerant of root pathogens.

Detection of root disease in coastal Douglas-fir stands using large scale 70-mm aerial photography

1984 ◽  
Vol 14 (4) ◽  
pp. 523-527 ◽  
Author(s):  
G. W. Wallis ◽  
Y. J. Lee
Keyword(s):  
Aerial Photography ◽  
Large Scale ◽  
Douglas Fir ◽  
Root Disease ◽  
Aerial Photographs ◽  
Stand Age ◽  
Adequate Information ◽  
Disease Occurrence ◽  
Mature Stands

Douglas-fir (Pseudotsugamenziesii (Mirb.) Franco) stands 15, 40, and 100 years of age containing root disease openings of various sizes were photographed using 70-mm Aerochrome color and color-infrared film at scales of 1:1 500 to 1:15 000. Success in detecting disease centers varied with scale relative to stand age and disease symptomatology. Scales of 1:6 000 provided adequate information for young stands 15–20 years of age whereas scales of up to 1:15 000 proved satisfactory for locating most centers in 100-year-old stands. The large variation in symptomatology among stands in the midage class made accurate assessment of disease occurrence difficult at all scales used. Measurement of area within most disease centers in a stand using aerial photographs is probably feasible only in mature stands. Color photographs were superior to color-infrared for detecting early foliage discoloration; the reverse was true when characterization of ground features and downed trees was desired.

scholarly journals Do the assemblages of benthic macroinvertebrates in nearshore waters of Western Australia vary among habitat types, zones and seasons?

2005 ◽  
Vol 85 (2) ◽  
pp. 217-232 ◽  
Author(s):  
M.D. Wildsmith ◽  
I.C. Potter ◽  
F.J. Valesini ◽  
M.E. Platell
Keyword(s):  
Species Composition ◽  
Benthic Macroinvertebrates ◽  
Habitat Type ◽  
Abundant Species ◽  
Subtidal Zone ◽  
Habitat Types ◽  
Environmental Characteristics ◽  
Deposit Feeding ◽  
Number Of Individuals

Benthic macroinvertebrates were sampled seasonally in the subtidal and upper and lower swash zones at two sites in each of six nearshore habitat types on the lower west coast of Australia. The habitat types, which differed mainly in the extent of their exposure to wave activity and whether sea grass and/or nearshore reefs were present, had been distinguished quantitatively using values for a suite of seven statistically-selected enduring environmental characteristics (Valesini et al., 2003). The core samples yielded 121 species representing eight phyla, among which the Polychaeta, Malacostraca and Bivalvia were the most speciose classes, contributing ∼38, 23 and 10%, respectively, to the total number of individuals. The total number of species and mean density of macroinvertebrates at the most protected habitat type (1), i.e. 70 and 209·2 individuals 0·1 m−2, respectively, were far greater than in any other habitat type. Habitat type influenced species composition to a greater extent than either zone or season. Furthermore, the extents of the differences among the species compositions of the six habitat types statistically matched the extents of the differences among the values for the suite of enduring environmental characteristics that distinguished each of those habitat types. Overall, the species composition at habitat type 1 was the most distinct, containing five abundant species of polychaetes that were adapted to deposit-feeding in calm waters with high levels of organic material and which were rare in all other habitat types. In contrast, the fauna at the most exposed habitat type was characterized by four crustacean species and a species of bivalve and polychaete, whose mobility and tough external surface facilitated their survival and feeding in turbulent waters. The zonal differences in faunal compositions among habitat types were greatest in the case of the subtidal zone. The faunal compositions differed among zones and seasons only at the most protected habitat type.

scholarly journals Recent Invasion of the Endemic Banggai Cardinalfish, Pterapogon kauderni at The Strait of Bali: Assessment of the Habitat Type and Population Structure

2019 ◽  
Vol 24 (1) ◽  
pp. 15 ◽  
Author(s):  
I Nyoman Giri Putra ◽  
I Dewa Nyoman Nurweda Putra
Keyword(s):  
Natural Habitat ◽  
Habitat Type ◽  
Marine Organisms ◽  
Aquarium Trade ◽  
Small Populations ◽  
Depth Range ◽  
Habitat Types ◽  
Weight Relationship ◽  
Narrow Bay ◽  
Sexually Mature

The demands of marine organisms for the aquarium trade are remain high and seems continue to increase. Consequently, many of marine organisms has been spread out from its natural habitat as in the case of endemic Banggai cardinalfish, (Pterapogon kauderni). That has invaded “new” habitat since it being trade in 1995. In recent years, a small populations of P. kauderni is known to be exist in a narrow bay near the Gilimanuk harbor, Bali. An underwater visual fish census survey was conducted on June 2018 to estimate the habitat types and densities of P. kauderni.  Additionally, 23 specimens of P. kauderni were collected randomly in order to assess biological parameters such as the length-weight relationship. We successfully recorded 30 groups of P. kauderni that inhabit a shallow areas with a depth range between 0.5m to 2m. Of these, more than 90% of the groups were found to be associated with sea urchin (Diadema sp.) while the rest were found to live together with branching coral (Acropora sp.) and branching sponge (Ptylocaulis sp.). Total number of fish observed during the survey were 381 individuals. The fish density is 0.76 individu.m-2. Length-weight relationship showed that P. kauderni exhibit is negative allometry (b<3) which mean that the increase in length is faster than the weight gain. Interestingly, from the 23 specimens collected, none of these were sexually mature (SL<41 mm) which may indicated that the population of P. kauderni in Bali are under serious threats of exploitation.     

scholarly journals Diet of otters (Lutra lutra) in various habitat types in the Pannonian biogeographical region compared to other regions of Europe

PeerJ ◽  
2016 ◽  
Vol 4 ◽  
pp. e2266 ◽  
Author(s):  
József Lanszki ◽  
István Lehoczky ◽  
Antoinette Kotze ◽  
Michael J. Somers
Keyword(s):  
Habitat Type ◽  
Hierarchical Cluster ◽  
Trophic Niche ◽  
Lutra Lutra ◽  
Fish Diet ◽  
Fish Farms ◽  
Habitat Types ◽  
Mediterranean Regions ◽  
Biogeographical Region ◽  
Study Sites

Knowledge of the effect of habitat type and region on diet and feeding behaviours of a species facilitates a better understanding of factors impacting populations, which contributes to effective conservation management. Using spraint analysis and relative frequency of occurrence data from the literature, we described the dietary patterns of Eurasian otters (Lutra lutra) in 23 study sites within the Pannonian biogeographical region in Hungary. Our results indicated that diet composition varied by habitat type and is therefore context dependant. The differences among habitat types were however lower than expected. We noticed a decline in the fish consumption with a concomitant increase in trophic niche breadth and amphibian consumption in rivers, ponds (fish farms), backwaters, marshes and small watercourses. The main differences in diet were not attributed to the consumption of primary and secondary food types (fish and amphibians), but rather to differences in other, less important food types (mammals, birds). Using hierarchical cluster analysis, rivers and ponds could clearly be separated from other habitat types. We found the main fish diet of otters in most of these areas consisted of small (<100 g), eurytopic, littoral and non-native, mostly invasive species. Dietary studies from 91 sites in six European biogeographical regions showed that fish are consumed most frequently in the Atlantic and Boreal, less in the Continental and Pannonian, and least in the Alpine and Mediterranean regions. Comparative analysis indicated that the Mediterranean region (with frequent crayfish consumption) and Alpine region (frequent amphibian consumption) cluster separate from the other regions.

scholarly journals Slenderness of trees in black locust stands

2018 ◽  
Vol 79 (2) ◽  
pp. 113-117
Author(s):  
Szymon Bijak ◽  
Katarzyna Orzoł
Keyword(s):  
Standard Deviation ◽  
Black Locust ◽  
Robinia Pseudoacacia ◽  
Habitat Type ◽  
Stand Age ◽  
Age Classes ◽  
Breast Height ◽  
Age Class ◽  
Crown Length ◽  
Research Material

Abstract This paper investigates the slenderness of black locust (Robinia pseudoacacia) trees in relation to the biosocial status of the trees, stand age class, crown parameters and habitat type. The research material was collected on 35 research plots in the Sława Śląska, Sulechów and Głogów forest districts in western Poland and comprises 1058 trees. For each tree, we measured height (h) as well as diameter at breast height (d) and determined its biosocial status (Kraft class), crown length (CL) and relative crown length (rCL). The age class and habitat type were assessed at the plot level. Because the obtained values for slenderness (s=h/d) diverged significantly from the normal distribution, we used Kruskal-Wallis and Mann-Whitney tests to investigate the influence of the above-mentioned parameters on the h/d ratio. Black locust slenderness ranged from 0.31 to 1.95 with an average of 0.91 (standard deviation 0.24). It furthermore differed significantly between Kraft classes (the higher the biosocial status, the lower the slenderness) and age classes (the older the trees, the lower their slenderness). We also found a significant effect of the habitat type (in oligotrophic sites trees formed more slender trunks than in mesotrophic sites) and crown parameters on the h/d ratio (decreasing with increasing crown length and relative crown length). The obtained results suggest that the slenderness of black locust does not differ substantially from native broadleaved trees in Poland.

scholarly journals Use of summer habitat by caribou on the north slope of a mountain near the Macmillan Pass, N.W.T.

Rangifer ◽  
1996 ◽  
Vol 16 (4) ◽  
pp. 311 ◽  
Author(s):  
James F. Quayle ◽  
G. Peter Kershaw
Keyword(s):  
Habitat Type ◽  
Indirect Evidence ◽  
High Elevation ◽  
North Slope ◽  
Habitat Types ◽  
The North ◽  
Feeding Cycle ◽  
Alpine Habitats ◽  
Pellet Density ◽  
Insect Harassment

Habitat use by woodland caribou was investigated by counting pellet-groups, sampling phytomass, and evaluating topography in nine habitat-types on the north slope of an unnamed mountain near Macmillan Pass, N.W.T. Caribou pellets were most abundant in high elevation habitat-types, and pellet density was greatest in an alpine Lichen-Grass habitat-type with a slope of &lt;1&deg;. The high density of pellets in alpine areas may have resulted from of the use of cool, windy, alpine habitats by caribou seeking relief from insect harassment. There were no apparent relationships between pellet abundance, and phytomass of mosses, lichens, or graminoids, possibly as a result of caribou feeding and defecating in different habitats. The occurrence of pellets with a coalesced morphology in the barren Lichen-Grass habitat-type provided indirect evidence in support of a feeding cycle, whereby caribou visit lush habitats to feed, and return to open, alpine habitats to rest and ruminate.

scholarly journals Effect of Climate and Habitat on Morphological Characteristics and Fruit Production of Picralima Nitida (Stapf) in West Africa

2021 ◽  
Author(s):  
Ghislain Comlan AKABASSI ◽  
Elie Antoine Padonou ◽  
Achille Ephrem Assogbadjo ◽  
Noël Zirihi Guede
Keyword(s):  
Pearson Correlation ◽  
Habitat Type ◽  
Morphological Characteristics ◽  
Botanical Garden ◽  
Fruit Production ◽  
Natural Forest ◽  
Home Gardens ◽  
Suitable Habitat ◽  
Habitat Types ◽  
Pharmaceutical Industries

Abstract Picralima nitida is an important African medicinal plant species used in pharmaceutical industries and traditional medicine to treat several diseases. Despite its importance, the species faces conservation problem. This study evaluated the effect of climate and habitat on morphological characteristics and fruit production of P. nitida. A total of 132 fruiting trees was randomly sampled from three habitat types (home gardens, botanical garden and natural forest) and three soils (Nitisols, Arenosols and Acrisols) in Dahomey Gap and Guineo-Congolese zone. A total of 5 morphological traits and fruit production were recorded per tree to describe the relationship between morphological determinism of the species and climate. Pearson correlation was performed to identify the suitable habitat type in each climatic zone. Harmonized World Soil Database was used to determine physicochemical characteristics of the soil types on which the species occurred. Results revealed that the climatic zones (p < 0.001) and habitat types (p < 0.0001) influenced significantly the morphological characteristics and fruit production of P. nitida. High trees with more number of fruits were observed in home gardens on acid soils (Nitisols (pH: 5) and Arenosols (pH: 5.3)) in Dahomey Gap. In Guineo-Congolese zone, the species was more present in natural forest on acid Acrisols (pH: 5).

scholarly journals Transforming Abandoned Farm Fields to Conifer Plantations Reduces Ruffed Grouse Density

2015 ◽  
Vol 6 (2) ◽  
pp. 405-417 ◽  
Author(s):  
Christian Roy ◽  
Marc J. Mazerolle ◽  
Louis Imbeau
Keyword(s):  
Wood Fiber ◽  
Habitat Type ◽  
Forest Harvesting ◽  
Old Fields ◽  
Ruffed Grouse ◽  
Natural Forests ◽  
Habitat Types ◽  
Rock Outcrops ◽  
Conifer Plantations ◽  
Coniferous Plantations

Abstract Natural forests likely will be unable to fulfill society’s needs sustainably for wood fiber in the near future. In an attempt to meet increasing demands while protecting intact forests, producers have increasingly considered alternative sources of timber, such as intensively managed plantations. In regions that are economically dependent on forest harvesting, abandoned farm fields are often targeted for conversion to intensive coniferous plantations. These sites are generally in an early successional stage that is dominated by deciduous stands, which provide an important habitat type for several game species, including ruffed grouse (Bonasa umbellus). Therefore, conversion could represent a loss of habitat for this species and several others that are associated with early successional deciduous stages. We conducted grouse drumming surveys in northwestern Quebec, Canada to evaluate the effects of transforming old fields into conifer plantations on ruffed grouse by comparing densities between two habitat types: abandoned farm fields (n  =  22) and old fields converted to conifer plantations (n  =  19). To correct any audibility bias between habitat types, we located all drumming males that were heard at each site. We then analyzed the number of individuals that were detected in the sites with repeated count models. Our results show that overall drumming males avoided plantations. Overhead cover increased drumming male densities in both habitat types, whereas lateral cover increased drumming grouse densities only in plantations. The density of deciduous stems and fruit-bearing stems also had a tendency to increase drumming male densities, but their effects were marginal. Most ruffed grouse in abandoned farm fields used piles of woody debris on the ground as drumming structures rather than large logs or rock outcrops. Our results suggest that plantations do not have the vegetative cover and quantity of food stems necessary to support high ruffed grouse densities during the drumming season and that conversion of abandoned farm fields to coniferous plantations may exert negative cascading effects for reproduction and population growth.

Benthic Habitats and the Effects of Fishing

2005 ◽  
Keyword(s):  
Habitat Type ◽  
High Energy ◽  
Benthic Habitat ◽  
Commercial Fishing ◽  
Placopecten Magellanicus ◽  
Benthic Species ◽  
Habitat Types ◽  
Closed Area ◽  
Sea Scallops ◽  
Moderate Complexity

<strong><em>Abstract. </em></strong>In late 1994, substantial portions of Georges Bank were closed to commercial fishing to assist with stock rebuilding. These areas were Closed Area I (CAI), located on the western portion of the bank, and Closed Area II (CAII), on the eastern portion. After about 5 years of closure, the southern portion of CAII and the central portion of CAI, having exhibited substantial increases in biomass and density of sea scallops <em>Placopecten magellanicus</em>, were reopened to scallop fishing. Before the industry was allowed entry, we conducted surveys to monitor the recovery of benthic habitat and fauna inside both areas. Sampling sites were selected in a paired station design for an inside–outside comparison representative of major habitat types in each closed area; other stations were chosen to survey the remainder of the closed areas. At each station, we examined a suite of biotic and abiotic variables ranging from substrate type to benthos to nekton. Our results suggest few differences between the inside–outside paired stations in both closed areas for nekton and benthic species composition and species richness. Fish abundance and biomass were similar inside and outside the closed areas. However, individuals of species such as skates (<em>Raja </em>spp.), haddock <em>Melanogrammus aeglefinus</em>, and flounders (Pleuronectiformes) were generally larger inside than outside the closed areas. Additionally, habitat type was important in determining the distribution, abundance, biomass, size, and feeding ecology for some of the more benthic-oriented species studied. In CAI, the differences we observed in the suite of biotic metrics are likely a result of the high diversity of habitat types, with many of the habitat types composed of higher-relief material (e.g., cobble, gravel, etc.) in the region. The seabed in the southern portion of CAII is a relatively high-energy sand habitat of low to moderate complexity and has a relatively low vulnerability to trawling and dredging, which may explain why there were less pronounced differences in abundance or biomass across habitat types in that closed area as compared to CAI. Other parts of closed areas on the northeastern shelf may exhibit more obvious changes in the same biological metrics due to the presence of more complex habitats and increased vulnerability to bottom tending fishing gear. Those differences we observed for CAI and CAII may have implications for the population dynamics of commercially valuable benthic species, yet that question remains a major challenge.

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