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PubMed2000

[Horizontal thermal characteristics at forest edge in calm tropical region of China].

The temperature measurement at southwest-facing edge of a rubber forest was conducted in a calm tropical region of Xishuangbanna, Yunnan, China in January 1998, and the daytime thermal characteristics and their time-space variations nearby the edge of the rubber forest were discussed. There was an obviously thermal effect at forest edge. The depth of edge influence on soil surface temperature was up to 13 m from the edge into the forest. Soil surface temperature reached its highest at 4.5 m outside the forest. The highest air temperature occurred at 0 m of the edge. The heat transfer nearby the edge was quite different in number and in direction. Outside the forest, the heat was transferred from ground to air on almost daytime, while at interior of forest, was opposite after the noon. The heat was transferred from the rubber canopy to the ground. At the forest edge, such variation was complex, depended mainly on location and time.

China↗
PubMedDate not supplied

[Spatial distribution of Cordyceps spp. (Ascomycotina: Clavicipitaceae) and its impact on the ants in forests of Amazonian Colombian foothill].

Entomopathogenic fungi of the genus Cordyceps were sampled in the foothills of the Colombian Amazon region (450-600 msnm altitude. January and May, 1998, i.e. dry and wet seasons, respectively). Healthy and Cordyceps-parasitized ants from a nearly pristine, a naturally disturbed and a human-disturbed forests were collected on 100 quadrants (1 m2) per forest. Litter, shrubs and trunks were explored as substrates, and samples were gathered in vertical strata from 50 cm to 2 m high. Azteca was the predominant ant genus in near pristine forest whereas Camponotus, Pheidole and Crematogaster were dominant in disturbed forests. In the naturally disturbed forest we found 759 individuals of Cordyceps unilateralis and 69 of C. lloydii var. binata parasitizing Camponotus spp. (Formicidae: Formicinae), whereas C. kniphofioides var. ponerinarum and C. australis were found only in six cases infecting the ants Paraponera clavata and Pachycondila crassinoda (Formicidae: Ponerinae). In the human disturbed forest it were found 34 individuals of C. unilateralis on Camponotus. In the near pristine forest we did not find parasitized ants. The Camponotus spp. ants parasitized by C. unilateralis and C. lloydii var. binata were found predominantly in the substratum foliage up to 1 m. It was concluded that the incidence of Cordyceps-ant interactions is not influenced by the conservation status of the forest. Instead, relative humidity and presence/absence of host ants appear to be key factors. Also, the microspatial distribution of the interactions seems to follow a definite pattern. This work observations support the hypothesis on coevolution of dispersion mechanisms in Cordyceps and ant pheromonal codes.

Animals↗
PubMed2002

[Bamboo rhizome system of mixed forest of Sassafras tsumu and Phyllostachys pubescens].

By the method of fixed plots, the bamboo rhizome system structure and nutrient content in rhizome from mixed Sassafras tsumu and Phyllostachys pubescens, which were established in 1983-1984 by planting S. tsumu on new-planted bamboo forests (3-4 years old), were investigated. The results showed that the mixtures with rational density of S. tsumu were suitable for optimizing the bamboo rhizome structure and increasing the nutrient content in rhizome. The total length and weight of rhizome, the diameter of rhizome and its evenness indices, the annual growth of new rhizome, the proportion of healthy rhizomes and buds, and the volume of rhizome system in the mixed bamboo forests with the density of 420-615 S. tsumu trees per hectare were higher than those in pure bamboo forest, respectively. The indexes mentioned above in mixed bamboo forests with the density of S. tsumu more than 735 trees per hectare were lower than those in pure bamboo forest, respectively, but the frequency of rhizome branch per unit length of rhizome was obviously higher than that in pure bamboo forest. The results of regression analysis showed that there were close relationships between S. tsumu density and total length of rhizome, the length between two joints, the growth of new rhizome, the diameter of rhizome and its evenness indices, and the frequency of rhizome branch per unit length of rhizome. The content of N, P, K, Ca, and Mg in the rhizome from mixed bamboo forests were higher than those in pure bamboo forest, respectively. For example, the content of N in rhizomes from mixtures was increased by 7.6-11.6% averagely.

Ecosystem↗
PubMed2003

CO2 deficit in temperate forest soils receiving high atmospheric N-deposition.

Evidence is provided for an internal CO2 sink in forest soils, that may have a potential impact on the global CO2-budget. Lowered CO2 fraction in the soil atmosphere, and thus lowered CO2 release to the aboveground atmosphere, is indicated in high N-deposition areas. Also at forest edges, especially of spruce forest, where additional N-deposition has occurred, the soil CO2 is lowered, and the gradient increases into the closed forest. Over the last three decades the capacity of the forest soil to maintain the internal sink process has been limited to a cumulative supply of approximately 1000 and 1500 kg N ha(-1). Beyond this limit the internal soil CO2 sink becomes an additional CO2 source, together with nitrogen leaching. This stage of "nitrogen saturation" is still uncommon in closed forests in southern Scandinavia, however, it occurs in exposed forest edges which receive high atmospheric N-deposition. The soil CO2 gradient, which originally increases from the edge towards the closed forest, becomes reversed.

Carbon Dioxide↗
PubMed2003

[Calculation of parameters in forest evapotranspiration model].

Forest evapotranspiration is an important component not only in water balance, but also in energy balance. It is a great demand for the development of forest hydrology and forest meteorology to simulate the forest evapotranspiration accurately, which is also a theoretical basis for the management and utilization of water resources and forest ecosystem. Taking the broadleaved Korean pine forest on Changbai Mountain as an example, this paper constructed a mechanism model for estimating forest evapotranspiration, based on the aerodynamic principle and energy balance equation. Using the data measured by the Routine Meteorological Measurement System and Open-Path Eddy Covariance Measurement System mounted on the tower in the broadleaved Korean pine forest, the parameters displacement height d, stability functions for momentum phi m, and stability functions for heat phi h were ascertained. The displacement height of the study site was equal to 17.8 m, near to the mean canopy height, and the functions of phi m and phi h changing with gradient Richarson number R i were constructed.

Mathematics↗
PubMed2004

[Spatial pattern analysis of forest landscape in low coteau of middle Qilian Mountains].

Based on the vegetation map and the relief map, using GIS and Fragstats, the spatial pattern of forest landscape of Xishui reserve in Qilian Mountains were analyzed. The results showed that the distribution of the vegetation was impacted mostly by altitude and aspect, grasslant was mostly distributed on the land of altitude 2,500-2,900 m and aspect of south and southwest, Picea crassifolia forest was always in the land of altitude 2,900-3,300 m and aspect of north, northeast, east and northwest, and shrubbery was in the land of altitude 3,300-3,700 m. The grassland had the biggest area and its connectivity and integrality were the best. The biggest MPFD of Picea crassifolia forest meant that its shape was the most complicated, its mean patch area was small, and the distance between the patches was short. So Picea crassifolia forest was easy to be impacted by some disturbance. The forest suitable land and Sabina przewalskii forest showed more outstretched characteristics than farmland and land with few trees. The mean nearest-neighbor distance of the poplar forest was the biggest in all the landscape elements, so the poplar forest's fragmentized degree was the highest in all the landscape elements.

Conservation of Natural Resources↗
PubMed2005

[Variability of the cytological parameters of Pinus sylvestris L. seeds from the unique Hrenovskoy pine forest].

Hrenovskoy pine forest is a unique island stand at the boundary of the species range of Scots pine Pinus sylvestris L. This object is of exceptional economic value, because it serves as a forest-seed base for the Voronezh oblast and some other regions of Russia; therefore, the stand and seed qualities have to be monitored constantly. The results of the first cytogenetic study of the seed progeny of P. sylvestris from the Morozov Grove, a high-quality stand in a reserved site within the Hrenovskoy pine forest, are reported. The studies have been performed in order to obtain a more correct assessment of seed quality based not only on their germination and energy of germination (traditionally used by forest breeders), but also on their genomic stability. The latter may be estimated by the stability of chromosome number in the somatic cells of seedlings and the regularity of mitotic divisions, because they also characterize the state of the generative system of parental forms and may serve as an integrated estimate of the stand development homeostasis. Therefore, the chromosome number, mitotic and nucleolar activities, and the number and spectrum of pathological mitoses (PMs) have been determined. Seedlings have been obtained from 240 seeds (collected from 12 trees) that resulted from free pollination. The cytological analysis of the rootlets of these seedlings has not detected any deviations from the chromosome number typical of the species P. sylvestris L. (2n = 24). However, considerable variation has been found in each family with respect to the mitotic index (MI) (from 4.2 +/- 0.36 to 8.1 +/- 0.39%) and the number of PMs (from 0.5 to 2.1%); micronuclei have also been found in each family (from 0.01 to 0.05%). In general, the phenotypic characteristics and the variation pattern of cytological parameters of the progeny of the trees studied in the Hrenovskoy pine forest, together with the high germination rate of seeds (90-98%), indicate that the current state of pines in the Hrenovskoy pine forest can be considered to be satisfactory. However, the presence of micronuclei in all variants and the decrease in MI in some individual plants (which was, on average, 6.1 +/- 0.03% in the sample studied, i.e., significantly lower than that of P. sylvestris from the Usmanskii pine forest (7.3 +/- 1.2%), where the conditions are optimal for this species) may serve as the bioindicators of the deterioration of both the state of trees themselves and the ecological conditions in the Hrenovskoy pine forest. Therefore, the population structure of this valuable autochtonic stand should be reproduced urgently.

Genomic Instability↗
PubMed2005

[Effects of forest vegetation on runoff and sediment production on sloping lands of Loess area].

Based on the 1985 - 2003 fixed-position data in 9 runoff plots of Caijiachuan watershed in the Jixian county of Shanxi Province in loess area, this paper discussed the relationships between vegetation and runoff and sediment production on sloping lands of loess area. The results showed that natural-secondary forest had better function in soil and water conservation than artifical Robinia pseudoacacia forest, with runoff and sediment produced 65% - 82% and 23% - 92%, respectively. Multiple regression analysis indicated that runoff and sediment production had a significant correlation with rainfall and its intensity, but this relationship was decreased gradually with increasing canopy density. Different land-use type had different runoff and sediment production, e. g., Ostryopsis davidiana and natural-secondary forests had the least runoff and sediment production, artificial Robinia pseudoacacia and Pinus tabulaeformis forests had 5 folds of it as much as Ostryopsis davidiana forest, mixed apple trees and crops had 17.14 and 3.96 folds of it than Ostryopsis davidiana forest, respectively, while high-standard soil preparation could decrease the production obviously. Gray correlation analysis suggested that the stand canopy density and the biomass of herb and litter were the most important factors affecting the runoff and sediment production on sloping land, whose gray correlation degrees all exceeded 0.6. Mixed forest with multi-layer stand structure and shrub forest should be developed in vegetation re-construction of loess area, which could help to increase the coverage and litter thickness to dramatically decrease the runoff and sediment production on sloping land.

Betulaceae↗
PubMedDate not supplied

[The role of historical processes in determining tree species richness in the forests of Western Caucasus].

To estimate the role of history in variation of tree species richness in the forests of the Western Caucasus we analyzed correlation between their local richness (S--the mean number of species per 300 m2) and size of actual species pool (N--the number of species per 1 ha). If compared communities are differently distant from the point of evolutionary equilibrium one should expect a significant variation in correlation between S and N (determined with the greater sensitivity of N than S in respect of historical factors). The lower value of N/S corresponds to less saturated level of historically determined species richness. A mean N/S ratio in Japana temperate broadleaved forests (Masaki et al., 1999) provided the basis for analysis. The present tree species richness of the forest communities in the 1 ha plots seem essentially determined by the historical processes. The mountain forest communities of Western Caucasus are characterized on the average with lower saturation level of the actual tree species pool in comparison with the Japan temperate broad-leaved forest communities. On the Western Caucasus the middle mountain beech and coniferous-broadleaved communities (400-1600 m a.s.l.) are characterized with the higher saturation level of the actual species pool in comparison with communities located lower and higher. These results confirm published historical reconstructions, according to which the middle mountain forest communities in the Western Caucasus are older than forests located higher or lower. Present low mountain forests of the southern (to Black Sea) and the northern macroslopes of the Western Caucasus are characterized with similar saturation level of the actual species pool. These data agree with the assumption of Dolukhanov (1980) that low mountain zone of the southern macroslope was not a refuge for tree species in Pleistocene.

Biological Evolution↗
PubMed1996

Dynamics of malaria transmission in forested and deforested regions of Mandla District, central India (Madhya Pradesh).

A longitudinal malaria study was undertaken in 1990-91 in 2 adjacent ecological zones in central India: villages in forest and villages away from the forest. The prevalence of Anopheles species varied widely between the 2 ecological settings. In the villages in forest, Anopheles culicifacies and An. fluviatilis were mainly exophilic, whereas in the villages away from forest, An. culicifacies was predominantly endophilic and An. fluviatilis was equally prevalent both indoors and outdoors. The seasonal patterns of malaria transmission were also different between the 2 zones. Plasmodium falciparum was the dominant parasite species in the villages in forest, whereas malaria infection was mainly due to Plasmodium vivax in the villages away from forest. The annual parasite incidence was high in the villages in forest. The failure to control malaria in forested areas is rooted in the terrain and a variety of poorly understood sociological factors.

Animals↗
PubMed1988

Law No. 2 relating to the conservation, protection, and development of forests, their rational economic exploitation, and the preservation of the ecological equilibrium, 30 October 1987.

This Law provides that the preservation and protection of forests constitute a issue of national interest to Romania and that the defense and improvement of the ecological equilibrium of the environment by preserving and protecting forests constitute a basic duty of state bodies, cooperatives, and all citizens. Among the methods of preserving the forests are the following: 1) the limitation of woodcutting; 2) the use of wood harvesting and collection techniques that do not affect the ecological equilibrium; 3) afforestation; and 4) the prevention of damage to forests and forest soil. The Law contains detailed chapters on the preservation and development of forests and the promotion of certain tree varieties and on the regeneration of forests. The Law also sets forth penalties for infractions.

Conservation of Natural Resources↗
PubMed2005

Primate assemblage structure in Amazonian flooded and unflooded forests.

There is considerable variation in primate species richness across neotropical forest sites, and the richest assemblages are found in western Amazonia. Forest type is an important determinant of the patterns of platyrrhine primate diversity, abundance, and biomass. Here we present data on the assemblage structure of primates in adjacent unflooded (terra firme) and seasonally inundated (várzea and igapó) forests in the lower Purús region of central-western Brazilian Amazonia. A line-transect census of 2,026 km in terra firme, 2,309 km in várzea, and 277 km in igapó was conducted. Twelve primate species were recorded from 2,059 primate group sightings. Although terra firme was found to be consistently more species-rich than várzea, the aggregate primate density in terra firme forest was considerably lower than that in the species-poor várzea. Consequently, the total biomass estimate was much higher in várzea compared to either terra firme or igapó forest. Brown capuchin monkeys (Cebus apella) were the most abundant species in terra firme, but were outnumbered by squirrel monkeys (Saimiri cf. ustus) in the várzea. The results suggest that floodplain forest is a crucial complement to terra firme in terms of primate conservation in Amazonian forests.

Animals↗
PubMed2006

Life on the edge: gastrointestinal parasites from the forest edge and interior primate groups.

Humans are responsible for massive changes to primate habitats, and one unanticipated consequence of these alterations may be changes in host-parasite interactions. Edges are a ubiquitous aspect of human disturbance to forest landscapes. Here we examine how changes associated with the creation of edges in Kibale National Park, Uganda, alter the parasite community that is supported by two species of African colobines: the endangered red colobus (Piliocolobus tephrosceles) and the black-and-white colobus (Colobus guereza). An analysis of 822 fecal samples from edge and forest interior groups revealed no difference in the richness of parasite communities (i.e., the number of parasite species recovered from the host's fecal sample). However, for both species the proportion of individuals with multiple infections was greater in edge than forest interior groups. The prevalence of specific parasites also varied between edge and forest interior groups. Oesophagostomum sp., a potentially deleterious parasite, was 7.4 times more prevalent in red colobus on the edge than in those in the forest interior, and Entamoeba coli was four times more prevalent in red colobus on the edge than in animals from the forest interior. Environmental contamination with parasites (measured as parasite eggs/gm feces) by red colobus from the edge and forest interior differed in a similar fashion to prevalence for red colobus, but it did not differ for black-and-white colobus. For example, egg counts of Oesophagostomum sp. were 10 times higher in red colobus from the edge than in those from the interior. The less severe infections in the black-and-white colobus relative to the red colobus may reflect the fact that black-and-white colobus raid agricultural crops while red colobus do not. This nutritional gain may facilitate a more effective immune response to parasites by the black-and-white colobus. The fact that animals on the edge are likely not nutritionally stressed raises an intriguing question as to what facilitates the elevated infections in edge animals. We speculate that interactions with humans may be linked to the observed patterns of infections, and hence that understanding the ecology of infectious diseases in nonhuman primates is of paramount importance for conservation and potentially for human-health planning.

Animals↗
PubMed2002

A dynamic model for intertemporal allocation of old-growth forests in the Pacific Northwest.

Across the globe, continued policy debates regarding the management of old-growth forests center around the difficult task of balancing economic and ecological considerations. Though the forests of the Pacific Northwest United States are among the most studied old-growth ecosystems, ecological and economic analyses have yielded public land management directives that remain controversial. Specifically, the recently adopted Northwest Forest Plan lacks explicit goals for maintaining intergenerational equity for the use of forest resources and the diversity of old-growth ecosystems. Unlike previous studies which rely on monetary quantification of costs and benefits, this study develops and applies a conceptual framework for evaluating socially optimal Pacific Northwest old-growth forest utilization strategies. Conditions for the optimal management of old-growth forests are derived using dynamic programming. The objective function synthesizes relevant biological and economic attributes of the old-growth allocation problem. Results in the form of extraction paths are compared given social pressure for consumptive and non-consumptive benefits, as well as different planning horizons, rates of social time preference, and environmental variance. Lengthening the planning horizon results in a vast divergence of optimal policies in the absence of discounting. Extraction rates appear to approach zero as the planning horizon approaches infinity. While higher rates of social time preference increase the rate of extraction, forest stocks remaining at the terminal time period equal levels remaining with a lower discount rate. Increasing environmental variance results in a higher level of stock remaining at the terminal time period. This analysis, while specific to the old-growth controversy of the Pacific Northwest, does provide general guidelines for addressing similar problems of multiple uses of natural areas, particularly where such uses are mutually incompatible, or where one use may be irreversibly destructive to another.

Animals↗
PubMed2004

Microbial community structure and oxidative enzyme activity in nitrogen-amended north temperate forest soils.

Large regions of temperate forest are subject to elevated atmospheric nitrogen (N) deposition which can affect soil organic matter dynamics by altering mass loss rates, soil respiration, and dissolved organic matter production. At present there is no general model that links these responses to changes in the organization and operation of microbial decomposer communities. Toward that end, we studied the response of litter and soil microbial communities to high levels of N amendment (30 and 80 kg ha(-1) yr(-1)) in three types of northern temperate forest: sugar maple/basswood (SMBW), sugar maple/red oak (SMRO), and white oak/black oak (WOBO). We measured the activity of extracellular enzymes (EEA) involved directly in the oxidation of lignin and humus (phenol oxidase, peroxidase), and indirectly, through the production of hydrogen peroxide (glucose oxidase, glyoxal oxidase). Community composition was analyzed by extracting and quantifying phospholipid fatty acids (PLFA) from soils. Litter EEA responses at SMBW sites diverged from those at oak-bearing sites (SMRO, BOWO), but the changes were not statistically significant. For soil, EEA responses were consistent across forests types: phenol oxidase and peroxidase activities declined as a function of N dose (33-73% and 5-41%, respectively, depending on forest type); glucose oxidase and glyoxal oxidase activities increased (200-400% and 150-300%, respectively, depending on forest type). Principal component analysis (PCA) ordinated forest types and treatment responses along two axes; factor 1 (44% of variance) was associated with phenol oxidase and peroxidase activities, factor 2 (31%) with glucose oxidase. Microbial biomass did not respond to N treatment, but nine of the 23 PLFA that formed >1 mol% of total biomass showed statistically significant treatment responses. PCA ordinated forest types and treatment responses along three axes (36%, 26%, 12% of variance). EEA factors 1 and 2 correlated negatively with PLFA factor 1 ( r = -0.20 and -0.35, respectively, n = 108) and positively with PLFA factor 3 ( r = +0.36 and +0.20, respectively, n = 108). In general, EEA responses were more strongly tied to changes in bacterial PLFA than to changes in fungal PLFA. Collectively, our data suggests that N inhibition of oxidative activity involves more than the repression of ligninase expression by white-rot basidiomycetes.

Analysis of Variance↗
PubMed2004

Responses of nitrification and ammonia-oxidizing bacteria to reciprocal transfers of soil between adjacent coniferous forest and meadow vegetation in the Cascade Mountains of Oregon.

Despite the critical position of nitrification in N cycling in coniferous forest soils of western North America, little information exists on the composition of ammonia-oxidizing bacteria (AOB) in these soils, or their response to treatments that promote or reduce nitrification. To this end, an experiment was conducted in which a set of soil cores was reciprocally transplanted between adjacent forest (low nitrification potential) and meadow (high nitrification potential) environments, at two high-elevation (approximately 1500 m) sites in the H.J. Andrews Experimental Forest located in the Cascade Mountains of Oregon. Half of the cores were placed in screened PVC pipe (closed) to prevent new root colonization, large litter debris inputs, and animal disturbance; the other cores were placed in open mesh bags. A duplicate set of open and closed soil cores was not transferred between sites and was incubated in place. Over the 2-year experiment, net nitrification increased in both open and closed cores transferred from forest to meadow, and to a lesser extent in cores remaining in the forest. In three of four forest soil treatments, net nitrification increases were accompanied by increases in nitrification potential rates (NPR) and 10- to 100-fold increases in AOB populations. In open cores remaining in the forests, however, increases in net nitrification were not accompanied by significant increases in either NPR or AOB populations. Although some meadow soil treatments reduced both net nitrification and nitrification potential rates, significant changes were not detected in most probable number (MPN)-based estimates of AOB population densities. Terminal restriction fragment profiles (T-RFs) of a PCR-amplified 491-bp fragment of the ammonia monooxygenase subunit A gene (amoA) changed significantly in response to some soil treatments, and treatment effects differed among locations and between years. A T-RF previously shown to be a specific biomarker of Nitrosospira cluster 4 (Alu390) was widespread and dominant in the majority of soil samples. Despite some treatments causing substantial increases in AOB population densities and nitrification potential rates, nitrosomonads remained undetectable, and the nitrosospirad AOB community composition did not change radically following treatment.

Ammonia↗
PubMed2003

Introduced species and management of a Nothofagus/Austrocedrus forest.

Isla Victoria (Nahuel Huapi National Park, Argentina), a large island dominated by native Nothofagus and Austrocedrus forest, has old plantations of many introduced tree species, some of which are famed invaders of native ecosystems elsewhere. There are also large populations of introduced deer and shrubs that may interact in a complex way with the introduced trees, as well as a recently arrived population of wild boar. Long-standing concern that the introduced trees will invade and transform native forest may be unwarranted, as there is little evidence of progressive invasion, even close to the plantations, despite over 50 years of opportunity. Introduced and native shrubs allow scattered introduced trees to achieve substantial size in abandoned pastures, but in almost all areas neither the trees nor the shrubs appear to be spreading beyond these sites. These shrub communities may be stable rather than successional, but the technology for restoring them to native forest is uncertain and probably currently impractical. Any attempt to remove the exotic tree seedlings and saplings from native forest would probably create the very conditions that would favor colonization by exotic plants rather than native trees, while simply clear-cutting the plantations would be unlikely to lead to regeneration of Nothofagus or Austrocedrus. The key to maintaining native forest is preventing catastrophic fire, as several introduced trees and shrubs would be favored over native dominant trees in recolonization. Deer undoubtedly interact with both native and introduced trees and shrubs, but their net effect on native forest is not yet clear, and specific management of deer beyond the current hunting by staff is unwarranted, at least if preventing tree invasion is the goal. The steep terrain and shallow soil make the recently arrived boar a grave threat to the native forest. Eradication is probably feasible and should be attempted quickly.

Animals↗
PubMed2005

Modeling the influence of dynamic zoning of forest harvesting on ecological succession in a northern hardwoods landscape.

Dynamic zoning (systematic alteration in the spatial and temporal allocation of even-aged forest management practices) has been proposed as a means to change the spatial pattern of timber harvest across a landscape to maximize forest interior habitat while holding timber harvest levels constant. Simulation studies have established that dynamic zoning strategies produce larger tracts of interior, closed canopy forest, thus increasing the value of these landscapes for interior-dependent wildlife. We used the simulation model LANDIS to examine how the implementation of a dynamic zoning strategy would change trajectories of ecological succession in the Great Divide Ranger District of the Chequamegon-Nicolet National Forest in northern Wisconsin over 500 years. The components of dynamic zoning strategies (number of zones in a scenario and the length of the hiatus between successive entries into zones) and their interaction had highly significant impacts on patterns of forest succession. Dynamic zoning scenarios with more zones and shorter hiatus lengths increased the average amount of the forest dominated by early successional aspen (Populus sp.). Dynamic zoning scenarios with two zones produced more late successional mature northern hardwoods than scenarios with four zones. Dynamic zoning scenarios with very short (30 years) or very long (120 years) hiatus lengths resulted in more late successional mature northern hardwoods than scenarios with intermediate hiatus lengths (60 and 90 years). However, none of the dynamic scenarios produced as much late successional mature northern hardwoods as the static alternative. Furthermore, the amounts of all habitat types in all dynamic zoning scenarios fluctuated greatly in time and space relative to static alternatives, which could negatively impact wildlife species that require a stable amount of habitat above some minimum critical threshold. Indeed, implementing dynamic zoning scenarios of different designs would have both positive and negative effects on wildlife species and for other objectives of forest management.

Animals↗