Evaluation of a guild approach to habitat assessment for forest-dwelling birds

The applicability of the Habitat Evaluation Procedure (HEP) was assessed for several nongame bird species in the central Adirondack Mountains of New York. Measures for 24 avian species and 33 associated habitat variables were collected during the summers of 1985 and 1986. The accuracy of four published Habitat Suitability Index (HSI) models was examined: pileated and downy woodpeckers, black-capped chickadee, and veery. Chickadee and veery models were judged successful and were then used to predict habitat quality for respective avian foragingguild members. The HSI model/guild approach provided poor predictors of habitat quality for ubiquitous and uncommon species. Information on relative abundance within the geographic region and specific cover types must be included when designing habitat evaluations using the guild approach.     

FORESTS AND OTHER FACTORS ASSOCIATED WITH STREAMFLOWS IN EAST TEXAS1

Effects of proportion of watersheds in forest and watershed physiographic factors on mean annual streamflow (1965-76), median flow, and 12 flood flow characteristics were regionally analyzed for 19 unregulated streams in East Texas. Annual streamflow increased with decreasing proportion of forest area. Differences in annual streamflow between full forest cover and bare watersheds could be as much as 200 mm. Other things being equal, the minimum watershed area required to generate 0.142 cm (5 cfs), a criterion used by the U.S. Corps of Engineering in regulating dredge and fill activity for water pollution abatement in East Texas streams, is 70 km² (27 mi²). Of the 31 physio-climatic parameters analyzed, watershed area, percent forest area, shape index, spring precipitation, and annual temperature were the most significant in affecting streamflow characteristics in East Texas. Using 2-3 of these five variables, all of the 14 streamflow characteristics can be estimated with accuracy ranging from acceptable to excellent levels.     

Morphological and Physiological Damage by Surfactant-Polluted Seaspray on Pinus pinea and Pinus halepensis

This paper reports morphological and physiological damage caused by polluted seaspray to coastal pine forests in Liguria (Northern Italy) and suggests the most reliable parameters for surfactant-pollution biomonitoring. Concentrations of surfactants in surface seawater, seaspray, and that deposited on Pinus halepensis and Pinus pinea needles were determined in samples from five sites. Decline of the pines in the Western part of Liguria was greater than in the East, and was associated with higher surfactant levels deposited on the crowns. Chloride content of needles was higher in damaged pines, even if it did not reach toxic levels. Stomata micromorphologies did not differ between species in the crown parts facing the sea, while differences were significant in the back crown parts that were not directly exposed to polluted sea breezes. Water content and noon water potential indicated interference in water relations of damaged trees. In conclusion, none of the investigated parameters was by itself a comprehensive index of surfactant damage. A simultaneous survey of several parameters is suggested to investigate the impact of surfactants on coastal vegetation. The most useful parameters were: directionality of crown damage, surfactant depositions on the needles, chloride accumulation in the needles, structural injury to epistomatal chambers, needle water content and potential.     

Monitoring Sustainable Forest Management in Different Jurisdictions

The concept of sustainable forest management (SFM) requires forest resource managers to monitor and collect information pertaining to their environmental, economic and social impact. There are increasing expectations from a variety of publics (government, customers, and other stakeholders) that forests be demonstrably well-managed, creating incentives for forest managers to design credible systems for assessing their management performance. It is against this background that local, national and international approaches to regulating forest practices have been evolving. This article reviews the different dimensions of governance as they relate to monitoring and information reporting in the forest sector. Specifically, it discusses the changing role of sovereignty, the effects of globalization and the emergence of civil society stakeholders in forestry-related decision-making. Concepts such as sovereignty and globalization have important implications for monitoring forest practices and for defining SFM. Whether SFM standard creation and enforcement involves a sovereign, shared-sovereignty or civil society approach will affect the level and nature of SFM monitoring. As a result, we need to better consider the concept of monitoring appropriate to the scale and intensity of operations, how monitoring and information reporting standards differ between jurisdictions, and what this means for independently verifying SFM at an inter-jurisdictional level.     

Rational forest productivity decline

A whole forest optimisation model was employed to examine economic behaviour as it relates to long term, forest productivity decline in the boreal forests of Ontario, Canada. Our productivity investment model(PIM) incorporated a choice between productivity decline as representedby a drop in forest Site Class, and a fee to 'maintain' site productivity. Sensitivity analysis was used to determine the point at which these fees exceeded the value of the differential in timber volume between upper and lower site classes. By varying discount rate, 'productivity investment frontiers' were constructed, which highlight the effects of the magnitude in productivity decline, maintenance fees, and harvest flow constraints upon the occurrence and schedule of productivity declines. In presenting this simple approach to exploring the effects of economic choice upon forest productivity decline, the phenomena of 'natural capital divestment' within forestry is described.     

Detecting Differences in Crown Transparency Assessments Between Countries using the Image Analysis System Croco

Estimates of crown transparency calculated using the semi-automatic image analysis system CROCO were compared withthe visual estimates of survey teams from 12 European countries.For each of five European species (Norway spruce (Picea abies (L.) Karst.), silver fir (Abies alba Mill.), Scotspine (Pinus sylvestris L.), beech (Fagus sylvatica L.), oak (Quercus robur L.)) 15 trees were assessed. In 64\% of the comparisons, CROCO estimates and the survey teams' scores differed significantly, while differences between countries were significant in 58 % of all comparisons. We calculated Spearman's rank correlation and the standard deviation of the differences between CROCO and each country and between pairs of countries. We then computed the medians for CROCO and each country. CROCO and only a few countries hadfor all species a higher median correlation and lower median standard deviation than the median for the comparison between countries. In addition no country had a consistently higher correlation or lower standard deviation than CROCO. We concludethat CROCO can provide more consistent and less variable estimates of crown transparency than visual assessments and that it can serve as a reference to detect differences in visualtransparency assessments between countries over time.     

Monitoring of Biodiversity Indicators in Boreal Forests: a Need for Improved Focus

The general principles of scale and coarse and fine filters have been widely accepted, but management agencies and industry are still grappling with the question of what to monitor to detect changes in forest biodiversity following forest management. Part of this problem can be attributed to the lack of focused questions for monitoring including absence of null models and predicted effects, a certain level of disconnect between research and management, and recognition that monitoring can be designed as a research question. Considerable research from the past decade has not been adequately synthesized to answer important questions, such as which species or forest attributes might be the best indicators of change. A disproportionate research emphasis has been placed on community ecology, and mostly on a few groups of organisms including arthropods, amphibians, migratory songbirds, and small mammals, while other species, including soil organisms, lichens, bats, raptors, some carnivores, and larger mammals remain less well-known. In most studies of community ecology, the question of what is the importance, if any, of the regularly observed subtle changes in community structures, and causes of observed changes is usually not answered. Hence, our ability to deal with questions of persistence is limited, and demographic research on regionally--defined key species (such as species linked to processes, species whose persistence may be affected, species with large home ranges, species already selected as indicators, and rare and threatened species) is urgently needed. Monitoring programs need to be designed to enable managers to respond to unexpected changes caused by forest management. To do this, management agencies need to articulate null models for monitoring that predict effects, focus fine--scale monitoring on key species (defined by local and regional research) in key habitats (rare, declining, important) across landscapes, and have a protocol in place to adapt management strategies to changes observed. Finally, agencies must have some way to determine and define when a significant change has occurred and to predict the persistence of species; this too should flow from a well--designed null model.     

遥感解译监测鞍山市森林资源现状

利用美国陆地资源卫星TM5遥感信息，调查分析了鞍山市森林资源现状。结果表明，鞍山市共有森林资源466933．52hm^2，占全市土地面积的50．32％，其中灌木林占森林面积的81．11％。在此基础上，分析了存在的主要问题，并提出了恢复途径及生态建设模式。     

Deposition of Inorganic Particulate Aerosols to Vegetation - A New Method of Estimating

A new, direct method was developed for quantifying inorganic particulate aerosols trapped by the forest canopy, and for determining the resulting input of elements to a forest ecosystem. The method is based on direct measurements of only six parameters. Using this method, it is possible to determine the load of aerosols trapped by the forest canopy and deposited to leaves, as well as the load of aerosols falling to the forest floor by impaction on plants. It is also possible to estimate the aerosol input of soluble and insoluble elements to an ecosystem. With this new method it has been found that the load of aerosols trapped by the canopy of a mixed forest located in the Rybnik Coal Basin averaged 189.0 kg x ha-1 x growing season-1, or 39.3% of the total inorganic particles reaching the ecosystem. The trapped aerosols provided 13.4 kg x ha-1 of soluble nitrogen and 0.91 kg x ha-1 of insoluble nitrogen over the growing season. At the same time, the input of soluble nitrogen from the atmosphere with rainfall to an open area averaged 13.9 kg x ha-1, and the input of insoluble nitrogen with inorganic dusts averaged 1.4 kg x ha-1.     

A national ozone biomonitoring program--results from field surveys of ozone sensitive plants in northeastern forests (1994-2000)

Ozone biomonitoring is a detection and monitoring techniquethat involves documenting ozone-induced visible injury toknown ozone-sensitive species under conditions of ambientexposure. The USDA Forest Service administers a long-term,nationwide ozone biomonitoring program to address public andscientific concerns about ozone impacts on forest health. Asystematic grid is used as the basis for biomonitoring sitelocations. At each site, trained field crews evaluate amaximum of thirty plants of up to six species and record the amount and severity of leaf-injury on individualplants. Injury from ozone was found more often on biomonitoring sites in the eastern Unites States than in theinterior or west-coast areas. Further results from thenortheast reveal that in any year, there is a higherpercentage of ozone-injured plants with more severe symptomsin areas with relatively high ozone concentrations than inareas with relatively low ozone. In very dry years (e.g.,1999) the percentage of injured plants and injury severityestimates are both sharply reduced even though ambient ozoneexposures are high. These findings demonstrate thatbiomonitoring data provide meaningful evidence of when highozone concentrations during the growing season have biologicalsignificance. Any assessment of ozone stress in the forestenvironment must include both biomonitoring (i.e., plantresponse) and air quality data to be complete.