Changes in forest floor bryophyte (moss and liverwort) communities 4 years after forest harvest

2003 ◽  
Vol 81 (7) ◽  
pp. 714-731 ◽  
Author(s):  
Nicole J Fenton ◽  
Katherine A Frego ◽  
Mary R Sims
Keyword(s):  
Forest Floor ◽  
Community Change ◽  
Managed Forest ◽  
Forest Harvest ◽  
Potential Threat ◽  
Before And After ◽  
Canopy Removal ◽  
Forest Floor Disturbance ◽  
Managed Landscapes ◽  
Harvest Techniques

Forest harvest presents a potential threat to forest floor bryophyte communities primarily through alteration of the microclimate and disturbance of substrates on the forest floor. Management, including harvest, applied at the landscape scale creates patches of disturbance of differing severities at the spatial scale experienced by bryophytes. Presumably, bryophyte diversity in managed landscapes is best conserved by forest harvest techniques that minimize community change, thereby allowing disturbed communities to reassemble to approach predisturbance composition. We monitored bryophyte community reassembly by sampling quadrats established in a 54-ha management block of Acadian forest in New Brunswick, before and after harvest. Quadrats were either in unharvested areas, or experienced a range of disturbance severities from removal of some or all canopy, to forest floor disturbance with complete canopy removal. Bryophyte communities showed compositional change over 4 years, even in areas that were not harvested. Although species richness was maintained or recovered 4 years after harvest, changes in species composition were significant in all disturbance classes with greatest change related to forest floor disturbance. In particular, liverworts were lost in areas with forest floor disturbance. We suggest that the simplest method to reduce immediate species loss, and presumably promote conservation of bryophyte communities within managed forest landscapes, is to utilize techniques that reduce the area of forest floor and associated substrates that are physically disrupted.Key words: bryophyte, community change, disturbance, forest harvest, monitoring.

Effect of forest floor disturbance on seedling establishment of Chamaecyparislawsoniana

1980 ◽  
Vol 10 (4) ◽  
pp. 441-446 ◽  
Author(s):  
Donald B. Zobel
Keyword(s):  
Seedling Establishment ◽  
Forest Floor ◽  
Soil Disturbance ◽  
Litter Removal ◽  
Growing Seasons ◽  
Percentage Survival ◽  
Natural Seedling ◽  
Forest Floor Disturbance ◽  
Natural Stands ◽  
Port Orford Cedar

Native seeds of Chamaecyparislawsoniana (A. Murr.) Parl. (Port-Orford-cedar) were sown on treated 1-m2 plots in four natural stands in southwestern Oregon, U.S.A. Treatments, replicated four times per stand, were (1) control, with natural litter undis-turbed, (2) litter removed, (3) litter removed and burned with ash replaced on plot, and (4) spaded after litter removal. Eighty-nine percent of germination occurred in early to mid-June. The spading treatment had the most germinants and the most survivors. Litter removal and burning treatments supported many fewer germinants, had the smallest seedlings, and had no survival after two growing seasons. Percentage survival of the few germinants in the control was as good as for the spading treatment, 5–6% after three summers. Although much natural seedling establishment may occur on natural litter, soil disturbance appears to greatly increase the rate of establishment. Litter removal alone does not increase establishment.

Long-term forest utilization can decrease forest floor microhabitat diversity: evidence from boreal Fennoscandia

2004 ◽  
Vol 34 (2) ◽  
pp. 303-309 ◽  
Author(s):  
Timo Kuuluvainen ◽  
Raija Laiho
Keyword(s):  
Forest Floor ◽  
Natural Forest ◽  
Decayed Wood ◽  
Natural Forests ◽  
Managed Forest ◽  
Vegetation Zone ◽  
Forest Sites ◽  
History Of ◽  
Forest Utilization

Forest floor microhabitat diversity was studied in old Pinus sylvestris L. dominated forest sites in two regions within the middle boreal vegetation zone in Fennoscandia: in 50 managed forest sites in the Häme region in southwestern Finland and in 45 natural or old selectively logged forest sites in the Kuhmo–Viena region in northeastern Finland and northwestern Russia. The forests in the Häme region are characterized by a long history of forest utilization, while the forests in the Kuhmo–Viena region can be regarded as natural or near natural. The managed forest sites in Häme had significantly lower forest floor microhabitat diversity compared with natural and near-natural forests. Microhabitats that were significantly more scarce in managed versus natural and near-natural forest sites included humps, depressions, decayed wood, and vicinity of decayed wood. On the other hand, even ground was significantly more abundant in managed forest compared with natural and near-natural forest. Microhabitat availability was also reflected in the occurrence of tree saplings growing in different microhabitats. The results suggest that long-term forest utilization has decreased forest floor microhabitat diversity. This has occurred because of a decreased amount of fallen deadwood and, possibly, lack of soil disturbances because of fewer uprootings caused by falling trees.

scholarly journals Survival of Neonectria fuckeliana in woody material

2008 ◽  
Vol 61 ◽  
pp. 390-390
Author(s):  
A.J.M. Hopkins ◽  
M.A. Dick ◽  
I.G. Simpson
Keyword(s):  
New Zealand ◽  
Pinus Radiata ◽  
Forest Floor ◽  
Woody Debris ◽  
The Third ◽  
Significant Difference ◽  
Pathogen Survival ◽  
Before And After ◽  
Growth Loss ◽  
Neonectria Fuckeliana

In southern New Zealand Neonectria fuckeliana is associated with a stem flute canker of Pinus radiata which can result in severe stem malformation and growth loss This research consisting of three distinct experiments aimed to determine pathogen survival in processed and unprocessed wood and woody debris In the first experiment the survival of the pathogen in living trees was examined by sampling trees infected with N fuckeliana in 6 different years In the second experiment the survival of the pathogen in woody debris was examined using 36 infected logs in a range of sizeclasses The logs were left on the forest floor in shaded and unshaded conditions and sampled for N fuckeliana after 4 and 9 months The third experiment examined the survival of the pathogen in processed wood Boards cut from infected trees were tested in six standard timber drying treatments Boards were sampled before and after drying to determine the presence of living N fuckeliana Neonectria fuckeliana was successfully isolated from trees at all infection times tested The fungus was also successfully isolated from 81 of logs after 9 months on the forest floor There was no significant difference between shaded and unshaded treatments Neonectria fuckeliana was not found in any boards following kilndrying but was successfully isolated from 69 of infected boards subjected to the two standard airdrying treatments for 9 weeks

scholarly journals Primate selfies and anthropozoonotic diseases: lack of rule compliance and poor risk perception threatens orangutans.

2021 ◽  
Author(s):  
Andrea Molyneaux ◽  
Emma Hankinson ◽  
Mbra Kaban ◽  
Magdalena S. Svensson ◽  
Susan M. Cheyne ◽  
...  
Keyword(s):  
Disease Transmission ◽  
Government Officials ◽  
Potential Threat ◽  
High Position ◽  
Pongo Abelii ◽  
Rule Compliance ◽  
Close Proximity ◽  
Sumatran Orangutan ◽  
Before And After ◽  
Risk Of Disease

Our understanding of the transmission of anthropozoonotic diseases between humans and nonhuman primates, particularly great apes due to their close genetic relationship with humans, highlights a serious potential threat to the survival of these species. This is particularly the case at tourism sites where risk of disease transmission is increased. We focus on the interaction between tourists and the Critically Endangered Sumatran orangutan (Pongo abelii) at Bukit Lawang in the Gunung Leuser National Park, Indonesia, before and after the park was closed due to the threat of Covid-19 in April 2020. Through analysis of posts on Instagram we determine the extent of compliance by visitors with the rule to keep a minimum distance of 10 meters from orangutans and assess the positional behaviours of the orangutans. Of the 2,229 photographs we assessed between November 2019 and July 2020, 279 depicted one or more orangutans. Forty-two of these contained both a human and an orangutan, and of these all showed inappropriate behaviours (direct contact, feeding orangutans, close proximity <5m) providing direct evidence of noncompliance with the 10m distance rule. Most of these photographs additionally showed orangutans performing abnormal positional behaviours such as being low to or on the ground rather than their natural high position in the canopy; being near the ground and in close proximity to humans increases the risk of anthropozoonotic disease transmission. As expected, we found a significant decrease in number of photographs that were posted following the closure, and a decrease in the proportion of photographs that showed orangutans or tourists feeding orangutans. Tourists do not seem to perceive that they pose risks to the orangutans and therefore increased awareness, education and enforcement of rules by all stakeholders, tourism bodies and government officials need to be actioned in order to safeguard this important population, which is crucial to the future survival of the Sumatran orangutan.

Political Attitudes of Defeated Candidates in an American State Election

1970 ◽  
Vol 64 (3) ◽  
pp. 879-887 ◽  
Author(s):  
Chong Lim Kim
Keyword(s):  
Political Action ◽  
Political Attitudes ◽  
Research Strategy ◽  
System Stability ◽  
Political Activity ◽  
Direct Result ◽  
Science Literature ◽  
Structured Interviews ◽  
Potential Threat ◽  
Before And After

Electoral victories and defeats occur repeatedly. This is especially true in democratic political systems where key governmental roles are filled through periodic elections. The attitude of defeated candidates toward the regime norms directly affects the system stability, because disaffected by defeat, these candidates may withdraw their support for the regime and may also translate such disaffection into radical political action. Despite the potential threat the defeated electoral candidates can pose to democratic stability, their political attitudes have rarely been investigated systematically in political science literature. Do defeated candidates exhibit an attitude toward the democratic rules and norms governing electoral competition significantly different from that of winning candidates? Do defeated candidates become politically less active after the election than they were before? Under what conditions do they become disaffected with the democratic rules and norms? This paper attempts, first, to compare the political attitudes of both winning and losing candidates, and second, to explore the variables which might account for differences in such attitudes.The data used in this paper are derived from a larger study of political recruitment in Oregon. Structured interviews were conducted with both winning and losing candidates who ran for the Oregon House of Representatives in the 1966 election. The samples were interviewed at three different times: before and after the primary, and after the general election. This research strategy permits us to analyze the effect of the outcome of the election on the attitudes of the candidates. Data were collected on the candidates' degree of support for the democratic rules of competition, their expected changes in political activity as a result of participation in the election, their career ambitions, and the perceived reward-cost, i.e., the material and psychological gains or losses which accrue to the candidates as a direct result of their participation in the election.

scholarly journals Soil compaction due to forest harvest operations

2007 ◽  
Vol 42 (2) ◽  
pp. 257-264 ◽  
Author(s):  
Moacir de Souza Dias Junior ◽  
Sebastião da Fonseca ◽  
Cezar Francisco Araújo Júnior ◽  
Arystides Resende Silva
Keyword(s):  
Soil Compaction ◽  
Soil Samples ◽  
Compression Tests ◽  
Forest Harvest ◽  
Undisturbed Soil ◽  
Soil Class ◽  
Eucalyptus Plantation ◽  
Capacity Model ◽  
Preconsolidation Pressure ◽  
Before And After

The objective of this work was to determine, through the use of the bearing capacity model, the traffic effects of the forest harvest operations on the preconsolidation pressure (sigmap), during one cycle of the eucalyptus plantation. The work was conducted using undisturbed soil samples, collected at the surface of the A horizon and in the top of the B horizon of an Udult (PA), Aquox (FX) and Udox (LA) soils. The undisturbed soil samples were used in the uniaxial compression tests. The soil sampling was done before and after the harvest operations. The operations performed with the Forwarder caused greater soil compaction than the ones done with the Feller Büncher and Harvester. The percentage of soil samples, in the region with additional soil compaction, indicated that the Udult was the soil class more susceptible to soil compaction, followed by the Aquox and Udox. Despite Udult is the more susceptible to soil compaction, the regeneration of the soil structure in this soil class was more efficient than in Aquox. The percentage of soil samples with sigmap values in the region with additional soil compaction in 1996, 1998 and 2004, after harvest operations, indicated a sustainable forest exploration in this period.

Substrates mediate responses of forest bryophytes to a gradient in overstory retention

2014 ◽  
Vol 44 (8) ◽  
pp. 855-866 ◽  
Author(s):  
Charles B. Halpern ◽  
Martin Dovčiak ◽  
Lauren S. Urgenson ◽  
Shelley A. Evans
Keyword(s):  
Forest Management ◽  
Forest Floor ◽  
Environmental Changes ◽  
Basal Area ◽  
Species Evenness ◽  
Substrate Quality ◽  
Area 7 ◽  
Dispersed Retention ◽  
Canopy Removal

Forest bryophytes are sensitive to the disturbances and environmental changes associated with forest management. We asked whether the substrates on which bryophytes grow mediate responses to exposure following canopy removal. We measured bryophyte cover and richness in 0.1 m2 quadrats on the forest floor, decayed logs, and tree bases along a gradient of dispersed overstory retention (100%, 40%, and 15% of initial basal area) 7 to 8 years after harvest of mature Pseudotsuga forests. Cover, local richness, and, to a lesser degree, species evenness declined steeply across the retention gradient on decayed logs and tree bases but not on the forest floor. Liverworts were more sensitive than mosses, particularly on decayed logs and on the southwestern aspects of trees (>97% declines in cover under 15% retention). Richness and evenness at the treatment scale also declined sharply on decayed logs and on the southwestern aspects of trees but changed little or increased under 40% retention on the forest floor. Our results indicate that even moderate levels of dispersed retention cannot sustain the abundance and overall diversity of wood-associated bryophytes in these forests. During regeneration harvests, conservation of these species may require retention of intact forest aggregates in which substrate quality and microclimatic stability can be maintained.

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