scholarly journals Monitoring recovery of overgrazed lichen communities on Hagemeister Island, southwestern Alaska

Rangifer ◽  
2021 ◽  
Vol 41 (1) ◽  
pp. 1-12
Author(s):  
Patrick Walsh ◽  
Trevor Goward
Keyword(s):  
Community Composition ◽  
Recovery Rate ◽  
Rangifer Tarandus ◽  
Growth Curves ◽  
Full Recovery ◽  
Lichen Community ◽  
Forage Species ◽  
Northern Regions ◽  
Southwestern Alaska

Understanding the recovery rate of overgrazed lichen communities has value to mangers of lands in northern regions.  We describe lichen community composition and present recovery rate measurements for a 12-year period following overgrazing by reindeer (Rangifer tarandus) on Hagemeister Island, Alaska.  Reindeer were removed from the island in 1993 following overgrazing and average total lichen biomass increased from 504.2 kg/ha (SD 205.4) in 2003 to 795.3 (SD 489.6) in 2015.  We estimate time to recovery with three competing growth curves which estimate grazeable biomass may be reached in 34-41 years.  However, estimates of full recovery to climax biomass varied among the models, ranging from 71 to 400 years.   In 2015, lichen communities were composed of various mixtures of at least 78 lichen taxa, and were dominated by Cladina stygia and other important reindeer forage species.   While reindeer overgrazing diminished forage quantity, it did not extirpate preferred forage taxa.  

Geographic variation in caribou on the Canadian arctic islands

1982 ◽  
Vol 60 (10) ◽  
pp. 2442-2454 ◽  
Author(s):  
D. C. Thomas ◽  
P. Everson
Keyword(s):  
Geographic Variation ◽  
Rangifer Tarandus ◽  
Canadian Arctic ◽  
The Other ◽  
Long Bones ◽  
Body Measurements ◽  
Morphological Similarity ◽  
North Central ◽  
Barren Ground ◽  
Northern Regions

Analyses of body, leg bone, skull, and pelage data indicated a cline in the characters of caribou (Rangifer tarandus) from central Boothia Peninsula to the western Queen Elizabeth Islands. The main difference between the skulls of barren-ground caribou (R. t. groenlandicus) on central Boothia Peninsula and the more northerly Peary caribou (R. t. pearyi) was a shorter muzzle in the latter. Pelage tone was markedly lighter in Peary caribou and they were smaller in most body measurements, most notably in the length of long bones. Two major populations of Peary caribou were identified: one on the western Queen Elizabeth Islands (Parry Islands), the other on Somerset and Prince of Wales islands. Differences in skull size and form suggest that each population was composed of two or more subpopulations. The larger and darker R. t. groenlandicus occurred on north-central Boothia Peninsula and the two subspecies and apparent intergrades were present in winter on northern regions of the peninsula. The morphological similarity of Peary caribou on Somerset and Prince of Wales islands is explained by interisland movements resulting in genetic mixing. The same is true for caribou on the western Queen Elizabeth Islands and that population apparently has little genetic interchange with the other.

scholarly journals Observation-derived ice growth curves show patterns and trends in maximum ice thickness and safe travel duration of Alaskan lakes and rivers

2020 ◽  
Author(s):  
Christopher D. Arp ◽  
Jessica E. Cherry ◽  
Dana R.N. Brown ◽  
Allen C. Bondurant ◽  
Karen L. Endres
Keyword(s):  
Interannual Variability ◽  
Growth Curves ◽  
Cold Season ◽  
Ice Thickness ◽  
Observation Data ◽  
Regional Variability ◽  
Winter Climate ◽  
Ice Growth ◽  
Freshwater Ice ◽  
Northern Regions

Abstract. The formation, growth, and decay of freshwater ice on lakes and rivers are fundamental processes of northern regions with wide ranging implications for socio-ecological systems. Ice thickness at the end of winter is perhaps the best integration of cold-season weather and climate, while the duration of thick and growing ice cover is a useful indicator for the winter travel and recreation season. Both maximum ice thickness (MIT) and ice travel duration (ITD) can be estimated from temperature-driven ice growth curves fit to ice thickness observations. We simulated and analyzed ice growth curves based on ice thickness data collected from a range of observation programs throughout Alaska spanning the past 20–60 years to understand patterns and trends in lake and river ice. Results suggest reductions in MIT (thinning) in several northern, interior, and coastal regions of Alaska and overall greater interannual variability in rivers compared to lakes. Interior regions generally showed less variability in MIT and even slightly increasing trends in at least one river site. Average ITD ranged from 214 days in the northern-most lakes to 114 days across southern-most lakes with significant decreases in duration for half of sites. River ITD showed low regional variability, but high interannual variability, underscoring the challenges with predicting seasonally-consistent river travel. Standardization and analysis of these ice observation data provide a comprehensive summary for understanding changes in winter climate and its impact on freshwater ice services.

The effects of bark quality on corticolous lichen community composition in urban parks of southern Ontario

Botany ◽  
2017 ◽  
Vol 95 (12) ◽  
pp. 1141-1149 ◽  
Author(s):  
L. McDonald ◽  
M. Van Woudenberg ◽  
B. Dorin ◽  
A.M. Adcock ◽  
R.T. McMullin ◽  
...  
Keyword(s):  
Community Composition ◽  
Tree Species ◽  
Urban Parks ◽  
Tree Bark ◽  
Significant Variable ◽  
Southern Ontario ◽  
Lichen Community ◽  
Wide Range ◽  
The City ◽  
Common Tree

Tree bark characteristics influence lichen colonization. To better understand how urban parks can be managed to maximize lichen biodiversity, we examined trees in seven parks throughout the City of Guelph in southern Ontario. We measured bark characteristics and lichen communities on four common tree species that have a wide range of pH: Acer platanoides L., Acer × freemanii E. Murray, Pinus resinosa Aiton, and Pinus strobes L. We recorded the lichen species on 99 trees, calculated the pH and fissuring of the bark, and determined the diameter at breast height (DBH) as a proxy for age. Gamma diversity on all trees included 18 lichen taxa. We used graphite bark rubbings analyzed in ImageJ 1.47v to calculate the degree of bark fissuring. We collected bark samples from each tree trunk and determined the acidity with a pH meter. Using multivariate analyses we show that lichen community composition is positively correlated with DBH and tree species, but the degree of fissuring did not have a significant effect. We could not statistically analyze pH independent of tree species, but our results suggest pH is not a significant variable. We show lichen biodiversity in urban parks can be increased by planting a variety of tree species at different ages.

Effects of two silvicultural regimes with large tree retention on epiphytic macrolichen communities in Adirondack northern hardwoods, New York, USA

2007 ◽  
Vol 37 (10) ◽  
pp. 1854-1866 ◽  
Author(s):  
Heather T. Root ◽  
Gregory G. McGee ◽  
Ralph D. Nyland
Keyword(s):  
New York ◽  
Community Composition ◽  
Old Growth ◽  
Epiphytic Lichen ◽  
Tree Diameter ◽  
Diameter At Breast Height ◽  
Breast Height ◽  
Lichen Community ◽  
Selection Systems ◽  
Large Trees

We sampled epiphytic lichen communities in nine Adirondack northern hardwood stands: three old growth, three reserve shelterwood, and three single-tree selection systems. Our objectives were to assess the effects of treatment, tree diameter at breast height, and their interaction on lichen communities and to determine whether lichen traits were associated with particular habitats. Lichen community composition was strongly related to tree diameter at breast height and differed between old growth and reserve shelterwoods. Lichen community composition was also related to an interaction between tree size and stand type. Lobaria pulmonaria (L.) Hoffm. was associated with large trees in old growth, whereas Evernia mesomorpha Nyl., Parmelia sulcata Taylor, and Physcia millegrana Degel. characterized those in shelterwood stands. Nitrophilous lichens were most common on small trees and in reserve shelterwoods, whereas small trees in selection systems and old growth supported lichens that were found to be most associated with larger trees overall. Selection systems apparently maintained lichen communities indistinguishable from those in old growth or reserve shelterwood. Because large trees hosted unique epiphyte assemblages particularly rich in fruticose and cyanolichen species, we expect that management retaining few or no large trees will alter epiphytic lichen communities.

Resource Management Biology for the Edible Kelp Cymathere triplicata

1984 ◽  
Vol 41 (2) ◽  
pp. 271-277 ◽  
Author(s):  
William G. Roland
Keyword(s):  
Resource Management ◽  
Moisture Content ◽  
Recovery Rate ◽  
Standing Crop ◽  
Control Area ◽  
Spore Production ◽  
Basal Part ◽  
Full Recovery ◽  
Overwinter Mortality

Sporophytes of Cymathere triplicata appeared only in spring and density declined thereafter; overwinter mortality was 100%. Standing crop estimates were highest during May–July. Plants were heaviest and generally had the longest and widest laminae in July and August. Thickness of laminae increased through December, the greatest increase being in the basal part of the lamina. Sori were initiated in August and approximately 90% of plants were fertile by September. Epibiota were most abundant during August–October. Moisture content decreased 2–3% from spring through winter. A plot subjected to almost total harvest in August had approximately 50% recovery of standing crop after 1 yr and full recovery after 2 yr, compared with a control area. A comparable recovery rate was seen for a similar September harvest. Sustained yields for a region of coastline should be maintained if no more than 50% of the standing crop is removed by intensive harvesting within plots, and if harvesting is not allowed prior to spore production. Best quality laminae in terms of length, thickness, weight per area, and moisture content occurred in August and September.

scholarly journals Exploring Rice Root Microbiome; The Variation, Specialization and Interaction of Bacteria and Fungi In Six Tropic Savanna Regions in Ghana

2020 ◽  
Vol 12 (14) ◽  
pp. 5835
Author(s):  
Makoto Kanasugi ◽  
Elsie Sarkodee-Addo ◽  
Richard Ansong Omari ◽  
Khondoker Mohammad Golam Dastogeer ◽  
Yoshiharu Fujii ◽  
...  
Keyword(s):  
Community Composition ◽  
Fungal Community ◽  
Fungal Diversity ◽  
Rice Root ◽  
Total Carbon ◽  
Soil Nitrate ◽  
Fungal Community Composition ◽  
Northern Regions ◽  
Bacteria And Fungi ◽  
Root Microbiome

We investigated the root microbiomes of rice sampled from six major rice-producing regions in Ghana using Illumina MiSeq high-throughput amplicon sequencing analysis. The result showed that both bacterial and fungal community compositions were significantly varied across the regions. Bacterial communities were shaped predominantly by biotic factors, including root fungal diversity and abundance. In contrast, fungal communities were influenced by abiotic factors such as soil nitrate, total carbon and soil pH. A negative correlation between the diversity and abundance of root fungi with soil nitrate (NO3-) level was observed. It suggested that there were direct and indirect effects of NO3- on the root-associated bacterial and fungal community composition. The gradient of soil nitrate from North to South parts of Ghana may influence the composition of rice root microbiome. Bacterial community composition was shaped by fungal diversity and abundance; whereas fungal community composition was shaped by bacterial abundance. It suggested the mutualistic interaction of bacteria and fungi at the community level in the rice root microbiome. Specific bacterial and fungal taxa were detected abundantly in the ‘Northern’ regions of Ghana, which were very low or absent from the samples of other regions. The analysis of indicator species suggested that an ‘ecological specialization’ may have occurred which enabled specific microbial taxa to adapt to the local environment, such as the low-nitrate condition in the Northern regions.

Food intake of reindeer in winter

2003 ◽  
Vol 141 (1) ◽  
pp. 93-101 ◽  
Author(s):  
P. V. STOREHEIER ◽  
B. E. H. VAN OORT ◽  
M. A. SUNDSET ◽  
S. D. MATHIESEN
Keyword(s):  
Food Intake ◽  
Dry Matter ◽  
Rangifer Tarandus ◽  
Dry Matter Intake ◽  
Faecal Output ◽  
Northern Regions ◽  
In Captivity ◽  
Ad Libitum ◽  
Few Data ◽  
Free Ranging

Management of semi-domesticated reindeer (Rangifer tarandus tarandus) in the northern regions have historically focused on reindeer–vegetation interactions, while few data on the food intake of these animals exist. Dry matter intake (DMI) was therefore estimated successively during winter in reindeer calves fed (i) ad libitum pelleted reindeer feed (RF-80; n=6), (ii) fed ad libitum mixed lichens (n=6) and (iii) in free-ranging reindeer calves (n=3) on natural winter pasture (March/April; 69 °N). Faecal output, determined with faeces collection bags, was 24±4, 6±3 and 22±3 g DM/day/kg BM0·75 in reindeer fed RF-80, mixed lichens and on winter pasture, respectively. Actual DMI of reindeer in captivity fed RF-80 and mixed lichens was 70±10 g DM/day/kg BM0·75 and 27±8 g DM/day/kg BM0·75, respectively. The DMI of the captive reindeer calves was accurately estimated on both diets on the basis of the digestibility of their diet and their faecal output. Using the same method, the DMI of free-ranging reindeer calves on natural winter pastures in northern Norway was estimated to be 34–61 g DM/day/kg BM0·75. The present study discusses factors that influence the food intake of reindeer in winter with emphasis on the seasonal regulation of appetite and DMI in these Arctic ruminants.

Age, growth, and latitudinal patterns of two Rajidae species in the northwestern Atlantic: little skate (Leucoraja erinacea) and winter skate (Leucoraja ocellata)

2006 ◽  
Vol 63 (5) ◽  
pp. 1078-1091 ◽  
Author(s):  
Michael G Frisk ◽  
Thomas J Miller
Keyword(s):  
New England ◽  
Gulf Of Maine ◽  
Growth Curves ◽  
Von Bertalanffy ◽  
Southern New England ◽  
Asymptotic Size ◽  
Cape Hatteras ◽  
Northern Regions ◽  
Significant Length ◽  
Latitudinal Patterns

Vertebral samples of little skate (Leucoraja erinacea) and winter skate (Leucoraja ocellata) were collected from Cape Hatteras, USA, to Canadian waters to estimate age, growth, and length at weight relationships for both species throughout this range. Maximum observed age was 12.5 and 20.5 years for little skate and winter skate, respectively. Significant length at weight relationships were found for both species. von Bertalanffy growth curves for the northwestern Atlantic were estimated for little skate (k = 0.19, L∞ = 56.1 cm, t0 = –1.17, p < 0.0001, n = 236) and winter skate (k = 0.07, L∞ = 122.1 cm, t0 = –2.07, p < 0.0001, n = 229). Additionally, latitudinal patterns in size and growth were observed in little skate, with individuals in northern regions growing slower and reaching a larger asymptotic size: von Bertalanffy growth estimates (mid-Atlantic, k = 0.22, L∞ = 53.26 cm, t0 = –1.04, p < 0.0001; southern New England – Georges Bank, k = 0.20, L∞ = 54.34 cm, t0 = –1.22, p < 0.0001; Gulf of Maine, k = 0.18, L∞ = 59.31 cm, t0 = –1.15, p < 0.0001). Although differences were observed for sex-specific growth curves for both species, only winter skate curves were significantly different.

scholarly journals Population dynamics of caribou herds in southwestern Alaska

Rangifer ◽  
2003 ◽  
Vol 23 (5) ◽  
pp. 131 ◽  
Author(s):  
Patrick Valkenburg ◽  
Richard A. Sellers ◽  
Ronald C. Squibb ◽  
James D. Woolington ◽  
Andrew R. Aderman ◽  
...  
Keyword(s):  
Rangifer Tarandus ◽  
Management Plan ◽  
Population Declines ◽  
Red Foxes ◽  
Alaska Peninsula ◽  
Naturally Occurring ◽  
Northern Alaska ◽  
Significant Mortality ◽  
Southwestern Alaska

The five naturally occurring and one transplanted caribou (Rangifer tarandus granti) herd in southwestern Alaska composed about 20% of Alaska's caribou population in 2001. All five of the naturally occurring herds fluctuated considerably in size between the late 1800s and 2001 and for some herds the data provide an indication of long-term periodic (40-50 year) fluctuations. At the present time, the Unimak (UCH) and Southern Alaska Peninsula (SAP) are recovering from population declines, the Northern Alaska Peninsula Herd (NAP) appears to be nearing the end of a protracted decline, and the Mulchatna Herd (MCH) appears to now be declining after 20 years of rapid growth. The remaining naturally occurring herd (Kilbuck) has virtually disappeared. Nutrition had a significant effect on the size of 4-month-old and 10-month-old calves in the NAP and the Nushagak Peninsula Herd (NPCH) and probably also on population growth in at least 4 (SAP, NAP, NPCH, and MCH) of the six caribou herds in southwestern Alaska. Predation does not appear to be sufficient to keep caribou herds in southwestern Alaska from expanding, probably because rabies is endemic in red foxes (Vulpes vulpes) and is periodically transferred to wolves (Canis lupus) and other canids. However, we found evidence that pneumonia and hoof rot may result in significant mortality of caribou in southwestern Alaska, whereas there is no evidence that disease is important in the dynamics of Interior herds. Cooperative conservation programs, such as the Kilbuck Caribou Management Plan, can be successful in restraining traditional harvest and promoting growth in caribou herds. In southwestern Alaska we also found evidence that small caribou herds can be swamped and assimilated by large herds, and fidelity to traditional calving areas can be lost.

Sign in / Sign up

Export Citation Format

Share Document