Tree community shifts and Acorn Woodpecker population increases over three decades in a Californian oak woodland

2015 ◽  
Vol 45 (8) ◽  
pp. 1113-1120 ◽  
Author(s):  
Devin E. McMahon ◽  
Ian S. Pearse ◽  
Walter D. Koenig ◽  
Eric L. Walters
Keyword(s):  
Canopy Cover ◽  
Basal Area ◽  
Valley Oak ◽  
Potential Habitat ◽  
Tree Community ◽  
Live Oak ◽  
Melanerpes Formicivorus ◽  
Community Shifts ◽  
Acorn Woodpeckers ◽  
Black Oak

Forest communities change in response to shifting climate, changing land use, and species introductions, as well as the interactions of established species. We surveyed the oak (Quercus L. spp.) community and Acorn Woodpecker (Melanerpes formicivorus (Swainson, 1827)) population within 230 ha of oak forest and savanna in central coastal California in 1979 and 2013 to assess demographic changes over a timescale relevant to mature oaks. Overall, percent canopy cover increased, particularly where coast live oak (Quercus agrifolia Née) and California black oak (Quercus kelloggii Newberry) were most abundant. The density of stems of Q. agrifolia increased, whereas the density of stems and basal area of valley oak (Quercus lobata Née), a species favored by Acorn Woodpeckers, decreased. The number of Acorn Woodpeckers and woodpecker territories increased over the study period, coincident with the increase in percent canopy cover; however, these increases were not related spatially. Instead, increased acorn production associated with broad-scale canopy growth likely more than compensated for the loss of Q. lobata. Our findings suggest that forests in this area are becoming denser and savanna is becoming more open, which so far has supported an increase in the Acorn Woodpecker population, despite potential habitat loss if Q. lobata continues to decline.

scholarly journals Foraging patterns of acorn woodpeckers (Melanerpes formicivorus) on valley oak (Quercus lobata Née) in two California oak savanna-woodlands

Oecologia ◽  
2010 ◽  
Vol 166 (1) ◽  
pp. 187-196 ◽  
Author(s):  
Douglas G. Scofield ◽  
Victor Ryan Alfaro ◽  
Victoria L. Sork ◽  
Delphine Grivet ◽  
Edith Martinez ◽  
...  
Keyword(s):  
Oak Savanna ◽  
Foraging Patterns ◽  
Quercus Lobata ◽  
Valley Oak ◽  
Melanerpes Formicivorus ◽  
Acorn Woodpeckers

scholarly journals Adjudicating Perspectives on Forest Structure: How Do Airborne, Terrestrial, and Mobile Lidar-Derived Estimates Compare?

2021 ◽  
Vol 13 (12) ◽  
pp. 2297
Author(s):  
Jonathon J. Donager ◽  
Andrew J. Sánchez Meador ◽  
Ryan C. Blackburn
Keyword(s):  
Ponderosa Pine ◽  
Laser Scanning ◽  
Canopy Cover ◽  
Basal Area ◽  
Tree Height ◽  
Absolute Error ◽  
Forest Monitoring ◽  
Individual Tree ◽  
Structural Configurations ◽  
Individual Trees

Applications of lidar in ecosystem conservation and management continue to expand as technology has rapidly evolved. An accounting of relative accuracy and errors among lidar platforms within a range of forest types and structural configurations was needed. Within a ponderosa pine forest in northern Arizona, we compare vegetation attributes at the tree-, plot-, and stand-scales derived from three lidar platforms: fixed-wing airborne (ALS), fixed-location terrestrial (TLS), and hand-held mobile laser scanning (MLS). We present a methodology to segment individual trees from TLS and MLS datasets, incorporating eigen-value and density metrics to locate trees, then assigning point returns to trees using a graph-theory shortest-path approach. Overall, we found MLS consistently provided more accurate structural metrics at the tree- (e.g., mean absolute error for DBH in cm was 4.8, 5.0, and 9.1 for MLS, TLS and ALS, respectively) and plot-scale (e.g., R2 for field observed and lidar-derived basal area, m2 ha−1, was 0.986, 0.974, and 0.851 for MLS, TLS, and ALS, respectively) as compared to ALS and TLS. While TLS data produced estimates similar to MLS, attributes derived from TLS often underpredicted structural values due to occlusion. Additionally, ALS data provided accurate estimates of tree height for larger trees, yet consistently missed and underpredicted small trees (≤35 cm). MLS produced accurate estimates of canopy cover and landscape metrics up to 50 m from plot center. TLS tended to underpredict both canopy cover and patch metrics with constant bias due to occlusion. Taking full advantage of minimal occlusion effects, MLS data consistently provided the best individual tree and plot-based metrics, with ALS providing the best estimates for volume, biomass, and canopy cover. Overall, we found MLS data logistically simple, quickly acquirable, and accurate for small area inventories, assessments, and monitoring activities. We suggest further work exploring the active use of MLS for forest monitoring and inventory.

A comparison of vegetative cover and tree community structure in three forested Adirondack watersheds

1985 ◽  
Vol 15 (5) ◽  
pp. 881-889 ◽  
Author(s):  
Christopher S. Cronan ◽  
Marc R. DesMeules
Keyword(s):  
New York ◽  
Sugar Maple ◽  
New York State ◽  
Basal Area ◽  
Red Maple ◽  
Vegetative Cover ◽  
Cover Type ◽  
Tree Community ◽  
Standing Dead ◽  
Annual Biomass

The Integrated Lake–Watershed Acidification Study (ILWAS) was conducted using three forested watersheds (Panther, Sagamore, and Woods) in the central Adirondack Park of New York State. By comparing the biogeochemical behavior of these watersheds, the ILWAS investigators hoped to elucidate the major ecosystem parameters controlling the fate of strong acids introduced from the atmosphere to lake–watershed systems. The ILWAS vegetation research program was designed to compare the quantitative patterns of forest structure in these midelevation watersheds. Results showed that the ILWAS catchments contain closely related variants of the northern hardwood – spruce – fir complex of the Adirondack region. The dominant tree species in these watersheds are beech (Fagusgrandifolia Ehrh.), red spruce (Picearubens Sarg.), sugar maple (Acersaccharum Marsh.), red maple (Acerrubrum L.), and yellow birch (Betulaalleghaniensis Britt.). On an areal basis, the watersheds contain 57–88% hardwood cover type and 5–29% spruce–fir cover type. Mean live basal area values range from 22 to 30 m2 ha−1 between catchments, while standing dead basal area values range from 4 to 8 m2 ha−1. Mean live stem densities range from 1400 to 1700 stems ha−1. Mean aboveground biomass projections for the tree stratum in the three watersheds range from 143 to 199 Mt ha−1, while estimated aboveground annual biomass increments range from 4.1 to 5.3% of standing biomass.

Phytophthora ramorum. [Distribution map].

2006 ◽  
Author(s):  
Keyword(s):  
South Carolina ◽  
Phytophthora Ramorum ◽  
Distribution Map ◽  
Quercus Agrifolia ◽  
Quercus Kelloggii ◽  
Live Oak ◽  
Lithocarpus Densiflorus ◽  
Black Oak ◽  
New Distribution ◽  
Distribution In Europe

Abstract A new distribution map is provided for Phytophthora ramorum Werres, de Cock & Man in't Veld. Oomycota: Pythiales. Hosts include California black oak (Quercus kelloggii), California live oak (Quercus agrifolia), Rhododendron, shreve oak (Quercus parvula var. shrevei), tanoak (Lithocarpus densiflorus) and Viburnum. Information is given on the geographical distribution in Europe (Belgium, Denmark, France, Germany, Ireland, Italy, Netherlands, Norway, Poland, Slovenia, Spain, Sweden, Switzerland, UK) and North America (Canada (British Columbia), USA (California, Florida, Georgia, Louisiana, Oregon, South Carolina, Tennessee, Virginia, Washington)).

scholarly journals Late Summer and Fall Nesting in the Acorn Woodpecker and Other North American Terrestrial Birds

The Condor ◽  
2007 ◽  
Vol 109 (2) ◽  
pp. 334-350
Author(s):  
Walter D. Koenig ◽  
Justyn T. Stahl
Keyword(s):  
Global Warming ◽  
North American ◽  
Breeding Success ◽  
Population Studies ◽  
Late Summer ◽  
Substantial Fraction ◽  
Melanerpes Formicivorus ◽  
Summer Temperatures ◽  
Total Productivity ◽  
Acorn Woodpeckers

Abstract Acorn Woodpeckers (Melanerpes formicivorus) at Hastings Reservation in central coastal California exhibit a bimodal peak in annual breeding activity. One peak occurs in spring during which the majority of breeding takes place, while a second is centered in late August as the new acorn crop matures. These latter nests are mostly initiated in late summer but often do not fledge until at least late September and are thus referred to here as ‘fall’ nests. Fall nests occur in about one-third of all years, taking place when the acorn crop is large and summer temperatures are relatively high. Fledglings from fall nests constitute 4.3% of the population's total productivity and survive and recruit to the population at levels comparable to spring fledglings. Fall nesting is less likely in groups in which either the male or female breeding adults have undergone a change from the prior year, but groups are otherwise indistinguishable. Ecologically, fall nesting is closely tied to the acorn crop and thus to breeding success in the following, rather than the prior, spring. Among North American terrestrial birds in general, fall breeding has been reported in 16% of all species and is significantly more common among residents and colonially nesting species, in which the frequency exceeds 25%. Furthermore, fall nesting is likely to have been underreported in the literature. Thus, this phenomenon is at least an irregular part of the breeding biology of a substantial fraction of North American birds and should be considered a possibility in population studies of temperate-zone species. This is especially true given that fall nesting is likely to increase as global warming takes place.

Structure and composition of unmanaged riparian forests in the coastal mountains of Oregon, U.S.A.

1999 ◽  
Vol 29 (10) ◽  
pp. 1557-1573 ◽  
Author(s):  
Robert J Pabst ◽  
Thomas A Spies
Keyword(s):  
Spatial Scales ◽  
Canopy Cover ◽  
Basal Area ◽  
Tree Regeneration ◽  
Riparian Forests ◽  
Stream Order ◽  
Third Order ◽  
First Order ◽  
Hardwood Tree ◽  
Stand Attributes

We characterized the structure and composition of unmanaged riparian forests in three river basins in Oregon's coastal mountains. Our objective was to evaluate stand attributes at three spatial scales: streamside (site), drainage network (stream order), and basin (subregion). Data on basal area, species composition, snag density, canopy cover, and tree regeneration were collected along transects at 124 sites. Conifer basal area increased with distance from stream, a trend similar among subregions, and was highest at sites along first-order streams. Hardwood basal area was relatively constant with distance from stream and was proportionally higher at sites along second- and third-order streams than at sites along first-order streams. Conifer and hardwood tree regeneration occurred infrequently and varied by topographic position, stream order, and subregion. Conifer regeneration was associated with basal area of shade-tolerant conifers and appeared to be limited by shrub competition. The unmanaged forests we studied were characterized by a patchy mosaic of structure and composition. Hardwoods and shrubs were major components of the near-stream environment in these forests, whereas dominance of conifers was limited to hillslopes. It appears that fine-scale patterns associated with proximity to the stream are influenced by coarser scale factors such as valley-floor width and climate.

Effects of variable-intensity logging on mammals, reptiles and amphibians at Waratah Creek, southeastern New South Wales

1998 ◽  
Vol 4 (4) ◽  
pp. 326 ◽  
Author(s):  
Rodney P. Kavanagh ◽  
Garry A. Webb
Keyword(s):  
Canopy Cover ◽  
Basal Area ◽  
Managed Forests ◽  
Variable Intensity ◽  
South Wales ◽  
Arboreal Marsupials ◽  
Sugar Glider ◽  
Before And After ◽  
Original Tree ◽  
Intensively Managed

Populations of arboreal marsupials, small ground-dwelling mammals, reptiles and amphibians were assessed in forest before and after logging. Different levels of canopy retention were specified to estimate the effect of varying intensities of logging on these fauna. The logging treatments imposed were; unlogged, and the retention of approximately 72%, 58% and 30% of the original canopy cover. This corresponded to 62%, 52% and 21 % retention of the original tree basal area on each logged area. The objectives of the study were to determine the sensitivity of species to logging, both in terms of the intensity of the initial impact and in terms of the time to recovery following disturbance, and to develop methods for managing areas within wood production forests where special wildlife values have been identified. A total of 53 species was recorded in the 500 ha study area, only 18 (34.0%) of which were abundant enough for assessments to be made about the effects of logging. The arboreal marsupials, in particular the Greater Glider Petauroides volans, were among the species more sensitive to logging disturbance. The small, ground-dwelling mammals and the reptiles that were sampled adequately in this study appeared to be relatively unaffected by logging or they recovered quickly (most within eight years, and probably all within 10?15 years) following logging. Despite a large survey effort, insufficient data were available to assess the effects of logging on most species of frogs, although two species may have been advantaged. The species requiring management consideration include those that declined as a result of logging, but which had not recovered within eight years (the Greater Glider, the Yellow-bellied Glider Petaurus australis, the Sugar Glider P. breviceps, and the skink Niveoscincus coventryi), the species that declined in both logged and unlogged areas (the frogs Pseudophryne bibronii, Limnodynastes peronii, Geocrinia victoriana and Heleioporus australiacus), and the species for which the data were too sparse to make any assessments. It is unclear when the species most disadvantaged by integrated logging, that is, the large gliding possums, will recolonize the logged areas. The persistence of these gliders was attributed to the retention of unlogged forest within and adjacent to logged areas. This highlights the role of riparian reserves ("wildlife corridors") and filter strips in retaining residual populations of the Greater Glider and the Yellow-bellied Glider until the logged areas are suitable for recolonization, and the importance of determining the effective size for these unlogged reserves. The data were not sufficient to determine conclusively whether reduced logging intensity at the levels applied was a better option than standard logging practices for managing populations of gliding possums in these forests. The results of this study, which was conducted in a forested landscape that was multi-aged but predominantly unlogged, may not be comparable to intensively-managed forests in which there is a lower proportion of unlogged forest and where multiple logging events have occurred.

Conservation value of koa (Acacia koa) reforestation areas on Hawaii Island

2018 ◽  
Vol 24 (1) ◽  
pp. 35
Author(s):  
Laurie Strommer ◽  
Sheila Conant
Keyword(s):  
Species Richness ◽  
Species Composition ◽  
Native Species ◽  
Canopy Cover ◽  
Basal Area ◽  
Forest Tree ◽  
Native Forest ◽  
Acacia Koa ◽  
Total Species Richness ◽  
Hawaii Island

Efforts to restore forests for ecological and economic benefit in Hawaii are converging on koa (Acacia koa), an endemic dominant or codominant canopy tree common across broad elevation and moisture gradients. We quantified plant species composition and forest structure in koa reforestation areas (KRAs) and in nearby intact native forest on Hawaii Island. Total species richness and percentage native species richness were lower in the plantation forests than in the intact forests, although species richness in the KRAs at one site was not significantly different from that in intact forest. Tree, sapling, and seedling densities differed between KRAs and forest sites at one site. At another, the native forest and one KRA had similar tree and seedling densities and similar canopy height and percentage canopy cover. Total stand basal area was greatest in the intact forest at both sites, although the basal area for the KRAs at one site exceeded those for intact forest at the other. Koa plantings can be structurally similar to intact forests though species composition differs. Our results suggest that koa forestry can facilitate native understorey development in some cases.

Ecosystem management applications of resource objective wildfires in forests of the Grand Canyon National Park, USA

2020 ◽  
Vol 29 (2) ◽  
pp. 190
Author(s):  
Michael T. Stoddard ◽  
Peter Z. Fulé ◽  
David W. Huffman ◽  
Andrew J. Sánchez Meador ◽  
John Paul Roccaforte
Keyword(s):  
Ponderosa Pine ◽  
Grand Canyon ◽  
Canopy Cover ◽  
Basal Area ◽  
Natural Disturbance ◽  
Forest Types ◽  
Mixed Conifer ◽  
Species Dominance ◽  
Management Objectives ◽  
Large Trees

Forest managers of the western United States are increasingly interested in utilising naturally ignited wildfires to achieve management objectives. Wildfires can accomplish a range of objectives, from maintenance of intact ecological conditions, to ecosystem restoration, to playing vital natural disturbance roles; however, few studies have carefully evaluated long-term effectiveness and outcomes of wildfire applications across multiple forest types. We remeasured monitoring plots more than 10 years after ‘resource objective’ (RO) fires were allowed to burn in three main south-western forest types. Results showed minimal effects and effective maintenance of open conditions in an intact pine-oak site. Higher-severity fire and delayed mortality of larger and older trees contributed to reductions in basal area and canopy cover at the mixed-conifer and spruce-fir sites. Species dominance shifted towards ponderosa pine in both the mixed-conifer and spruce-fir sites. Although fires resulted in 46–68% mortality of smaller trees initially, substantial ingrowth brought tree density to near pre-fire levels in all forest types after 12 years. Overall, the 2003 RO fires were broadly successful at maintaining or creating open and heterogeneous conditions and resulted in fire- and drought-tolerant species composition. These conditions are likely to be resilient to changing climate, at least in the short term. Substantial mortality of large trees and continuing loss of basal area, however, are a concern, given further climate warming.

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