scholarly journals Large-scale tree mortality from Rapid Ohia Death negatively influences avifauna in lower Puna, Hawaii Island, USA

The Condor ◽  
2019 ◽  
Vol 121 (2) ◽  
Author(s):  
Richard J Camp ◽  
Dennis A LaPointe ◽  
Patrick J Hart ◽  
Daniel E Sedgwick ◽  
Lisa K Canale
Keyword(s):  
Large Scale ◽  
Tree Mortality ◽  
Bird Community ◽  
Abundant Species ◽  
Metrosideros Polymorpha ◽  
Vascular Wilt ◽  
Point Counts ◽  
Canker Pathogen ◽  
Hawaii Island ◽  
The Impact

Abstract ‘Ōhi’a lehua (Metrosideros polymorpha) is the principle tree species in forests across the Hawaiian Islands and provides critical foraging and nesting habitat for native passerines. Rapid Ohia Death (ROD), caused by the vascular wilt fungus Ceratocystis lukuohia and the canker pathogen C. huliohia, was first detected in the Puna District of Hawaii Island in 2010. It affects all life stages of ‘ōhi’a and as of July 2018 had spread to an estimated 40,469 ha across Hawaii Island. To determine the impact of ROD on the forest bird community we conducted point counts in lowland ‘ōhi’a forest in 2016 and compared them to counts from 2003 to 2004, before the appearance of ROD. We found an increase in species diversity and a significant decrease in the densities of a native Hawaiian honeycreeper, the Hawaii Amakihi (Chlorodrepanus virens), and the nonnative Japanese White-eye (Zosterops japonicus). Yellow-fronted Canary (Crithagra mozambica) and Saffron Finch (Sicalis flaveola), 2 nonnative passerines associated with the shrub layer and more open habitats, were only detected in 2016. Proportion of survey points occupied were comparable between survey periods, but relative abundances were generally lower. Hawaii Amakihi densities declined by 79% and Japanese White-eye densities declined by 33%. Our findings suggest that the loss of ‘ōhi’a canopy due primarily to ROD has adversely affected populations of native Hawaii Amakihi and nonnative Japanese White-eye, 2 of the most abundant species of lowland Hawaiian forests.

scholarly journals Mangrove bird community of Paranaguá Bay - Paraná, Brazil

2007 ◽  
Vol 50 (1) ◽  
pp. 75-83 ◽  
Author(s):  
Luiz Augusto Macedo Mestre ◽  
Ricardo Krul ◽  
Valéria dos Santos Moraes
Keyword(s):  
Human Impacts ◽  
Bird Species ◽  
Passer Domesticus ◽  
Bird Community ◽  
Abundant Species ◽  
Marine Conservation ◽  
Point Counts ◽  
Flying Insects ◽  
Paranaguá Bay ◽  
Conservation Plans

This study describes the mangrove bird community of Paranaguá Bay in Paraná - South Brazil. Seasonal surveys were conducted during September 1997 to September 1998 at three sites in Paranaguá Bay. Frequencies and abundances of birds were registered in 200m transects and one hour point counts. A total of 81 bird species were observed in the three sampling sites. Most of the bird species in Paranaguá mangroves are fruits, seeds and arthropods consumers, and predators of flying insects. The most frequent and abundant species were Egretta caerulea, Ceryle torquata, Chloroceryle amazona, Pitangus sulphuratus, Turdus amaurochalinus and Parula pitiayumi. The bird community of these three sites is composed mainly by forest bird species. The mangroves of Paranaguá Bay shelter one of the richest avifauna of Brazilian mangroves. Differences between sampling sites could be related to the proximity of the Paranaguá city and human impacts in the areas. Only in the most disturbed site were observed Passer domesticus and large flocks of Coragyps atratus. This study contributed to the knowledge of mangrove communities, and could be an important basis to fluvial-marine conservation plans in Paraná- Brazil.

Defoliation of tamarack by outbreak populations of larch sawfly in subarctic Quebec: measuring the impact on tree growth

1993 ◽  
Vol 23 (7) ◽  
pp. 1444-1452 ◽  
Author(s):  
Isabelle Tailleux ◽  
Conrad Cloutier
Keyword(s):  
Tree Growth ◽  
Large Scale ◽  
Tree Mortality ◽  
Sampling Site ◽  
Climatic Conditions ◽  
Soil Conditions ◽  
Outbreak Period ◽  
Larch Sawfly ◽  
Foliage Development ◽  
The Impact

In conjunction with other major perturbations, outbreaks of specialist insect defoliators could play a key role in the long-term evolution of northern forest communities. Sawfly oviposition marks up to 20 years old in shoots of tamarack, Larixlaricina (Du Roi) K. Koch, provide a direct record of a large-scale epidemic cycle of the larch sawfly, Pristiphoraerichsonii (Htg.), during the 1980s in the Grande Rivière de la Baleine region, northern Quebec. Because no significant tree mortality was noted in the years following peak defoliator populations in 1985–1986, a study was undertaken to determine whether insect population changes during the outbreak period were correlated with growth changes under various climatic and soil conditions in three coastal sites and one continental sampling site. The fluctuations with time in the density of oviposition marks on trees indicated that the epidemic cycle was synchronous at all sites. However, the defoliator's density was significantly higher at the inland site, located 150 km from Hudson Bay, than at the coastal sites, where climatic conditions may be less favorable to insect activity and survival. No significant effects on tree growth were detected at the coastal sites, whereas larch from the inland site recorded a significant reduction in radial growth in 1984, the 1st year of outbreak conditions. Larch from this site also showed significant effects on foliage development after 4 years of defoliation (1988), when a virtual stop on elongative growth became apparent. Larch trees reproduced actively during the outbreak, with peak reproductive effort in 1984 and 1987 correlating with lows in elongative growth. Delayed or minimal effects of this outbreak characterized by the presence of hundreds of sawfly colonies per tree and defoliation levels comparable to those observed in the boreal forest during similar outbreaks indicate that subarctic larch may be highly tolerant to prolonged defoliation by the larch sawfly.

scholarly journals The impact of Hurricane Michael on longleaf pine habitats in Florida

2019 ◽  
Author(s):  
Nicole E. Zampieri ◽  
Stephanie Pau ◽  
Daniel K. Okamoto
Keyword(s):  
Climate Change ◽  
Large Scale ◽  
Tree Mortality ◽  
Size Structure ◽  
Longleaf Pine ◽  
Pinus Palustris ◽  
Climate Change Impacts ◽  
The North ◽  
Integral Role ◽  
The Impact

AbstractThe longleaf pine (Pinus palustris) ecosystem of the North American Coastal Plain (NACP) is a global biodiversity hotspot. Disturbances such as tropical storms play an integral role in ecosystem maintenance in these systems. However, altered disturbance regimes as a result of climate change may be outside the historical threshold of tolerance. Hurricane Michael impacted the Florida panhandle as a Category 5 storm on October 10th, 2018. In this study, we estimate the extent of Florida longleaf habitat that was directly impacted by Hurricane Michael. We then quantify the impact of Hurricane Michael on tree density and size structure using a Before-After study design at four sites (two wet flatwood and two upland pine communities). Finally, we identify the most common type of tree damage at each site and community type. We found that 39% of the total remaining extent of longleaf pine habitat was affected by the storm in Florida alone. Tree mortality ranged from 1.3% at the site furthest from the storm center to 88.7% at the site closest. Most of this mortality was in mature sized trees (92% mortality), upon which much of the biodiversity in this habitat depends. As the frequency and intensity of extreme events increases, management plans that mitigate for climate change impacts need to account for large-scale stochastic mortality events in order to effectively preserve critical habitats.

Evidence for bottom-up effects in the boreal forest: Do passerine birds respond to large-scale experimental fertilization?

1995 ◽  
Vol 73 (12) ◽  
pp. 2231-2237 ◽  
Author(s):  
Nicholas F. G. Folkard ◽  
James N. M. Smith
Keyword(s):  
Species Richness ◽  
Boreal Forest ◽  
Large Scale ◽  
Bird Species ◽  
Passerine Bird ◽  
Spatial And Temporal Variation ◽  
Bottom Up ◽  
Bird Species Richness ◽  
Point Counts ◽  
The Impact

Boreal plant communities are strongly nutrient limited, and the animals of the boreal forest may therefore experience bottom-up nutrient limitation. We conducted a 5-year experimental study of the impact of aerial nitrogen fertilization on birds of the boreal forest near Kluane Lake, southwestern Yukon, to test for such bottom-up effects. Specifically, we tested if avian abundance and species richness increased after fertilization. Variable circular-plot point counts were made to estimate bird numbers and species richness each summer from 1988 to 1992. Fertilization had no effect on abundance for the first two summers, but total abundances of the seven commonest passerine bird species increased by an average of 46% over the final 3 years. Fertilization had no effect on bird species richness. Population densities and species richness were both low at Kluane compared with patterns seen in temperate forest. Yellow-rumped warblers (Dendroica coronata), dark-eyed juncos (Junco hyemalis), and Swainson's thrushes (Catharus ustulatus) dominated the passerine community at Kluane. There was only moderate spatial and temporal variation in songbird numbers on control plots over the 5-year study period.

Short-term impact of a spruce budworm outbreak on a deer wintering area

1980 ◽  
Vol 10 (4) ◽  
pp. 559-563 ◽  
Author(s):  
François Potvin
Keyword(s):  
Large Scale ◽  
Tree Mortality ◽  
Balsam Fir ◽  
Short Term ◽  
Deer Population ◽  
Dead Trees ◽  
Spruce Stands ◽  
Wintering Areas ◽  
Wintering Area ◽  
The Impact

The impact of the current budworm outbreak on deer (Odocoileusvirginianusborealis Miller) was studied from 1972 to 1979 in a wintering area located at the northern extremity of Témiscouata Lake, Québec. This area encompassed 20 km2 and consisted mostly of balsam fir (Abiesbalsamea (L.) Mill.) and spruce (Piceaglauca (Moench) Voss) stands which suffered high mortality in 1975. The proportion of coniferous cover dropped from 66 to 29% as a result of the outbreak. Nevertheless, the area occupied by deer and the deer population itself remained quite stable. Deer progressively deserted balsam fir - spruce stands and sought shelter in cedar (Thujaoccidentalis L.) stands that are well distributed throughout the study area. Elimination of balsam fir from the shrub layer of the more severely affected stands resulted in a loss of two-thirds of the browse biomass and invasion by raspberry (Rubusidaeus L.). Conversely, tree lichens on dead trees have become an important new food source. The impact of large-scale tree mortality by the budworm in wintering areas sharing the same ecological conditions may depend on the presence or absence of cedar stands as an alternative coniferous cover type.

scholarly journals Lianas Significantly Reduce Aboveground and Belowground Carbon Storage: A Virtual Removal Experiment

2021 ◽  
Vol 4 ◽  
Author(s):  
Félicien Meunier ◽  
Geertje M. F. van der Heijden ◽  
Stefan A. Schnitzer ◽  
Hannes P. T. De Deurwaerder ◽  
Hans Verbeeck
Keyword(s):  
Carbon Storage ◽  
Large Scale ◽  
Tree Mortality ◽  
Net Primary Productivity ◽  
Removal Experiment ◽  
Root Turnover ◽  
Turnover Rates ◽  
Belowground Carbon ◽  
The Impact

Lianas are structural parasites of trees that cause a reduction in tree growth and an increase in tree mortality. Thereby, lianas negatively impact forest carbon storage as evidenced by liana removal experiments. In this proof-of-concept study, we calibrated the Ecosystem Demography model (ED2) using 3 years of observations of net aboveground biomass (AGB) changes in control and removal plots of a liana removal experiment on Gigante Peninsula, Panama. After calibration, the model could accurately reproduce the observations of net biomass changes, the discrepancies between treatments, as well as the observed components of those changes (mortality, productivity, and growth). Simulations revealed that the long-term total (i.e., above- and belowground) carbon storage was enhanced in liana removal plots (+1.2 kgC m–2 after 3 years, +1.8 kgC m–2 after 10 years, as compared to the control plots). This difference was driven by a sharp increase in biomass of early successional trees and the slow decomposition of liana woody tissues in the removal plots. Moreover, liana removal significantly reduced the simulated heterotrophic respiration (−24%), which resulted in an average increase in net ecosystem productivity (NEP) from 0.009 to 0.075 kgC m–2 yr–1 for 10 years after liana removal. Based on the ED2 model outputs, lianas reduced gross and net primary productivity of trees by 40% and 53%, respectively, mainly through competition for light. Finally, model simulations suggested a profound impact of the liana removal on the soil carbon dynamics: the simulated metabolic litter carbon pool was systematically larger in control plots (+51% on average) as a result of higher mortality rates and faster leaf and root turnover rates. By overcoming the challenge of including lianas and depicting their effect on forest ecosystems, the calibrated version of the liana plant functional type (PFT) as incorporated in ED2 can predict the impact of liana removal at large-scale and its potential effect on long-term ecosystem carbon storage.

Impacts of the Mountain Pine Beetle on Sawmill Operations, Costs, and Product Values in Montana

2018 ◽  
Vol 68 (1) ◽  
pp. 15-24
Author(s):  
Dan Loeffler ◽  
Nathaniel Anderson
Keyword(s):  
Large Scale ◽  
Mountain Pine Beetle ◽  
Tree Mortality ◽  
Negative Impact ◽  
Rocky Mountain ◽  
Mountain Pine ◽  
Milling Operations ◽  
Pine Beetle ◽  
The Impact ◽  
Percent Decrease

Abstract Over the past 20 years, the mountain pine beetle (Dendroctonus ponderosae) has caused considerable tree mortality across the Rocky Mountain region of the western United States. Although the operational and cost impacts of dead timber are generally well known in the sawmill industry, there remains a need to better understand the impact of large-scale outbreaks on the industry at local and regional scales. Using an expert opinion survey of sawmill managers and procurement staff, this study quantified the relative importance of various cost and operations factors related to harvesting and processing beetle-killed timber in Montana. Respondents reported an average log supply of trees in the red or gray stage of mortality as 24.5 percent of log supply from 2010 to 2014, but this dropped to 5.8 percent by 2015. Cracking and checking were perceived as having the highest negative impact on log value, while waste in milling and breakage of logs in handling were ranked highest for milling operations. For a typical lodgepole pine stand, the volume estimated as sawlogs showed a 15 percent decrease between green and red stages and a 50 percent decrease between red and gray stages, with most of the volume change moving into the pulpwood category. Total average cost increases from green to gray for logging, loading and hauling, and sawmilling were 43, 46, and 46 percent, respectively. Results generally support known relationships between defects, costs, recovery, and value, with some interesting departures with regard to blue stain and equipment maintenance.

Changes in tree species abundance in a Neotropical forest: impact of climate change

1996 ◽  
Vol 12 (2) ◽  
pp. 231-256 ◽  
Author(s):  
Richard Condit ◽  
Stephen P. Hubbell ◽  
Robin B. Foster
Keyword(s):  
Large Scale ◽  
Forest Canopy ◽  
Tree Mortality ◽  
Population Change ◽  
Species Abundance ◽  
Severe Drought ◽  
Colonizing Species ◽  
Rate Of Increase ◽  
Drying Trend ◽  
The Impact

ABSTRACTThe abundance of all tree and shrub species has been monitored for eight years in a 50 ha census plot in tropical moist forest in central Panama. Here we examine population trends of the 219 most numerous species in the plot, assessing the impact of a long-term drying trend. Population change was calculated as the mean rate of increase (or decrease) over eight years, considering either all stems ≥10 mm diameter at breast height (dbh) or just stems ≥100 mm dbh. For stems ≥10 mm, 40% of the species had mean growth rates <1% per year (either increasing or decreasing) and 12% had changes ≥5% per year. For stems ≥100 mm, the figures were 38% and 8%.Species that specialize on the slopes of the plot, a moist microhabitat relative to the plateau, suffered significantly more declines in abundance than species that did not prefer slopes (stems ≥10 mm dbh). This pattern was due entirely to species of small stature: 91% of treelets and shrubs that were slope-specialists declined in abundance, but just 19% of non-slope treelets and shrubs declined. Among larger trees, slope and non-slope species fared equally. For stems ≥100 mm dbh, the slope effect vanished because there were few shrubs and treelets with stems ≥100 mm dbh. Another edaphic guild of species, those occurring preferentially in a small swamp in the centre of the plot, were no more likely to decline in abundance than non-swamp species, regardless of growth form. Species that preferentially colonize canopy gaps in the plot were slightly more likely to decrease in abundance than non-colonizing species (only for stems ≥10 mm dbh, not ≥100 mm). Despite this overall trend, however, several colonizing species had the most rapidly increasing populations in the plot.The impact of a 25-year drying trend and an associated increase in the severity of the 4-month dry season is having an obvious impact on the BCI forest. At least 16 species of shrubs and treelets with affinities for moist microhabitats are headed for extinction in the plot. Presumably, these species invaded the forest during a wetter period prior to 1966. A severe drought of 1983 that caused unusually high tree mortality contributed to this trend, and may also have been responsible for sharp increases in abundance of a few gap-colonizers because it temporarily opened the forest canopy. The BCI forest is remarkably sensitive to a subtle climatic shift, yet we do not know whether this is typical for tropical forests because no other large-scale censuses exist for comparison.

Impact of COVID-19 on Nuclear Medicine in Germany, Austria and Switzerland: An International Survey in April 2020

2020 ◽  
Vol 59 (04) ◽  
pp. 294-299 ◽  
Author(s):  
Lutz S. Freudenberg ◽  
Ulf Dittmer ◽  
Ken Herrmann
Keyword(s):  
Nuclear Medicine ◽  
Health Systems ◽  
Personal Protective Equipment ◽  
Large Scale ◽  
Diagnostic Procedures ◽  
Protective Equipment ◽  
Current Crisis ◽  
Web Based ◽  
Public Versus Private ◽  
The Impact

Abstract Introduction Preparations of health systems to accommodate large number of severely ill COVID-19 patients in March/April 2020 has a significant impact on nuclear medicine departments. Materials and Methods A web-based questionnaire was designed to differentiate the impact of the pandemic on inpatient and outpatient nuclear medicine operations and on public versus private health systems, respectively. Questions were addressing the following issues: impact on nuclear medicine diagnostics and therapy, use of recommendations, personal protective equipment, and organizational adaptations. The survey was available for 6 days and closed on April 20, 2020. Results 113 complete responses were recorded. Nearly all participants (97 %) report a decline of nuclear medicine diagnostic procedures. The mean reduction in the last three weeks for PET/CT, scintigraphies of bone, myocardium, lung thyroid, sentinel lymph-node are –14.4 %, –47.2 %, –47.5 %, –40.7 %, –58.4 %, and –25.2 % respectively. Furthermore, 76 % of the participants report a reduction in therapies especially for benign thyroid disease (-41.8 %) and radiosynoviorthesis (–53.8 %) while tumor therapies remained mainly stable. 48 % of the participants report a shortage of personal protective equipment. Conclusions Nuclear medicine services are notably reduced 3 weeks after the SARS-CoV-2 pandemic reached Germany, Austria and Switzerland on a large scale. We must be aware that the current crisis will also have a significant economic impact on the healthcare system. As the survey cannot adapt to daily dynamic changes in priorities, it serves as a first snapshot requiring follow-up studies and comparisons with other countries and regions.

Sign in / Sign up

Export Citation Format

Share Document