The purpose of the study was two-fold: to determine the nature of stainable deposits on periodontally diseased root surfaces subsequent to in vivo scaling and root planing procedures, and to quantify the distribution of residual plaque on instrumented root surfaces. Thirty molar and 30 nonmolar teeth which were condemned for periodontal or prosthetic reasons and had proximal probing depths of 4 to 7 mm were treated. Half of these were instrumented with I.U. curettes and the other half with an ultrasonic scaling device. Instrumentation was continued until the root surface felt hard and smooth to an explorer tip. The location of the gingival margin was recorded by notching the treated proximal surface with a No. 1/2 round bur. Twenty control teeth, 10 molar and 10 nonmolar, were extracted without instrumentation. Control and experimental teeth were irrigated with saline and stored in a 2.5% glutaraldehyde fixative solution until the time of assessment. All teeth were stained with a 0.5% solution of toluidine blue, and the amount of residual stained material and calculus was assessed under the stereomicroscope using an eyepiece fitted with a 10 X 10 optical grid. Stained deposits were marked by placing small V-shaped notches in the adjacent root surface as an aid to identification after the specimens were processed for scanning electron microscopic (SEM) examination. The nature of stained deposits on selected teeth was then characterized using the SEM. Treated root surfaces were also surveyed in detail to assess the quantity and extent of residual plaque deposits. The findings showed that although a large percentage of the treated proximal root surface may possess stainable deposits, these surfaces were often unexpectedly free of microbial organisms. In this study, the majority of stained deposits were composed of adherent fibrin and instrumentation debris. When bacterial plaque was present, it was usually found in small "mini-colonies" smaller than 0.5 mm across. Such findings cast doubt on the validity of using histologic and disclosing stains as an indicator for the presence of bacterial plaque immediately after instrumentation. Although only partially effective in removing subgingival calculus, both methods of instrumentation in this study appeared to be remarkably effective in bacterial debridement of subgingival root surfaces.

The value of information is a general and broadly applicable concept that has been used for several decades to aid in making decisions in the face of uncertainty. Yet there are relatively few examples of its use in ecology and natural resources management, and almost none that are framed in terms of the future impacts of management decisions. In this paper we discuss the value of information in a context of adaptive management, in which actions are taken sequentially over a timeframe and both future resource conditions and residual uncertainties about resource responses are taken into account. Our objective is to derive the value of reducing or eliminating uncertainty in adaptive decision making. We describe several measures of the value of information, with each based on management objectives that are appropriate for adaptive management. We highlight some mathematical properties of these measures, discuss their geometries, and illustrate them with an example in natural resources management. Accounting for the value of information can help to inform decisions about whether and how much to monitor resource conditions through time.

Source–sink theory provides an approach to identify habitat arrangements needed to sustain populations in spatially and temporally varying landscapes. Our objective was to investigate whether source–sink ideas could be applied to quantify how habitat arrangements influenced Florida Scrub‐Jay (Aphelocoma coerulescens) population dynamics, in order to enhance habitat restoration. From 1988 to 2001, we measured reproductive success, survival, immigration, emigration, pair bond fidelity, and the duration of delayed breeding by young. The arrangement of shrub height in each territory was used to classify habitat quality each year, according to the following categories: short (<120 cm tall), optimal (short plus 120–170 cm tall), tall mix (short or optimal and >170 cm), and tall (>170 cm). Annual demographic performance rates were calculated in each territory by summing the recruitment of potential breeders (the number of yearlings produced) and then subtracting the number of breeders that died. The mean demographic performance per breeding pair was −0.57, 0.33, −0.26, and −0.35, respectively, for short, optimal, tall mix, and tall territories. Optimal territories functioned as sources because recruitment exceeded mortality; hence, the optimal territories were net exporters to marginal habitat. Potential breeders were exported to sink territories by active dispersal and by “territory quality transitions,” whereby territories produced an excess of potential breeders while in optimal condition and then became marginal because of shifting territory boundaries and habitat conditions. Short, tall mix, and tall territories functioned as sinks because they were net importers, mortality exceeded recruitment, and because there were no density‐dependent reductions in their demographic performance. The population declined because there were too few optimal territories to offset declines in sinks, which usually had too much tall scrub even though most of the landscape had been burned recently. Successful habitat restoration requires greater emphases on improving habitat quality at the territory scale because this is the fundamental landscape unit related to demography. Source–sink ideas, complemented by territory quality transitions, provide a quantitative approach to directly relate habitat and demographic objectives. Corresponding Editor: D. J. Levey.

Quantifying habitat-specific survival and changes in habitat quality within disturbance-prone habitats is critical for understanding population dynamics and variation in fitness, and for managing degraded ecosystems. We used 18 years of color-banding data and multistate capture-recapture models to test whether habitat quality within territories influences survival and detection probability of breeding Florida Scrub-Jays (Aphelocoma coerulescens) and to estimate bird transition probabilities from one territory quality state to another. Our study sites were along central Florida's Atlantic coast and included two of the four largest metapopulations within the species range. We developed Markov models for habitat transitions and compared these to bird transition probabilities. Florida Scrub-Jay detection probabilities ranged from 0.88 in the tall territory state to 0.99 in the optimal state; detection probabilities were intermediate in the short state. Transition probabilities were similar for birds and habitat in grid cells mapped independently of birds. Thus, bird transitions resulted primarily from habitat transitions between states over time and not from bird movement. Survival ranged from 0.71 in the short state to 0.82 in the optimal state, with tall states being intermediate. We conclude that average Florida Scrub-Jay survival will remain at levels that lead to continued population declines because most current habitat quality is only marginally suitable across most of the species range. Improvements in habitat are likely to be slow and difficult because tall states are resistant to change and the optimal state represents an intermediate transitional stage. The multistate modeling approach to quantifying survival and habitat transition probabilities is useful for quantifying habitat transition probabilities and comparing them to bird transition probabilities to test for habitat selection in dynamic environments.

Many ecosystems are influenced by disturbances that create specific successional states and habitat structures that species need to persist. Estimating transition probabilities between habitat states and modeling the factors that influence such transitions have many applications for investigating and managing disturbance-prone ecosystems. We identify the correspondence between multistate capture-recapture models and Markov models of habitat dynamics. We exploit this correspondence by fitting and comparing competing models of different ecological covariates affecting habitat transition probabilities in Florida scrub and flatwoods, a habitat important to many unique plants and animals. We subdivided a large scrub and flatwoods ecosystem along central Florida's Atlantic coast into 10-ha grid cells, which approximated average territory size of the threatened Florida Scrub-Jay (Aphelocoma coerulescens), a management indicator species. We used 1.0-m resolution aerial imagery for 1994, 1999, and 2004 to classify grid cells into four habitat quality states that were directly related to Florida Scrub-Jay source-sink dynamics and management decision making. Results showed that static site features related to fire propagation (vegetation type, edges) and temporally varying disturbances (fires, mechanical cutting) best explained transition probabilities. Results indicated that much of the scrub and flatwoods ecosystem was resistant to moving from a degraded state to a desired state without mechanical cutting, an expensive restoration tool. We used habitat models parameterized with the estimated transition probabilities to investigate the consequences of alternative management scenarios on future habitat dynamics. We recommend this multistate modeling approach as being broadly applicable for studying ecosystem, land cover, or habitat dynamics. The approach provides maximum-likelihood estimates of transition parameters, including precision measures, and can be used to assess evidence among competing ecological models that describe system dynamics.

We expressed quantitative and qualitative uncertainties in suitability index functions as triangular distributions and used the mechanics of fuzzy numbers to solve for the distribution of uncertainty around the habitat suitability indices derived from them. We applied this approach to a habitat model for the Florida Scrub‐Jay. The results demonstrate that priorities and decisions associated with management and assessment of ecological systems may be influenced by an explicit consideration of the reliability of the indices.

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