Patches Of Different Ages Research Articles

Patch age alters seagrass response mechanisms to herbivory damage

Natural disturbances can produce a mosaic of seagrass patches of different ages, which may affect the response to herbivory. These pressures can have consequences for plant performance. To assess how seagrass patch age affects the response to herbivory, we simulated the effect of herbivory by clipping leaves of Halodule wrightii in patches of 2, 4 and 6 years. All clipped plants showed ability to compensate herbivory by increasing leaf growth rate (on average 4.5-fold). The oldest patches showed resistance response by increasing phenolic compounds (1.2-fold). Contrastingly, the concentration of phenolics decreased in the youngest patches (0.26-fold), although they had a similar leaf carbon content to controls. These results suggest that younger plants facing herbivory pressure reallocate their phenolic compounds towards primary metabolism. Results confirm the H. wrightii tolerance to herbivory damage and provides evidence of age-dependent compensatory responses, which may have consequences for seagrass colonization and growth in perturbed habitats.

Limited effects of population age on the genetic structure of spatially isolated forest herb populations in temperate Europe.

Due to multiple land-cover changes, forest herb populations residing in forest patches embedded in agricultural landscapes display different ages and, thus, experience differences in genetic exchange, mutation accumulation and genetic drift. The extent of divergence in present-day population genetic structure among these populations of different ages remains unclear, considering their diverse breeding systems and associated pollinators. Answering this question is essential to understand these species' persistence, maintenance of evolutionary potential and adaptability to changing environments. We applied a multi-landscape setup to compare the genetic structure of forest herb populations across forest patches of different ages (18-338 years). We studied the impact on three common slow-colonizer herb species with distinct breeding systems and associated pollinators: Polygonatum multiflorum (outcrossing, long-distance pollinators), Anemone nemorosa (outcrossing, short-distance pollinators) and Oxalis acetosella (mixed breeding). We aimed to assess if in general older populations displayed higher genetic diversity and lower differentiation than younger ones. We also anticipated that P. multiflorum would show the smallest while O. acetosella the largest difference, between old and young populations. We found that older populations had a higher observed heterozygosity (H o) but a similar level of allelic richness (A r) and expected heterozygosity (H e) as younger populations, except for A. nemorosa, which exhibited higher A r and H e in younger populations. As populations aged, their pairwise genetic differentiation measured by D PS decreased independent of species identity while the other two genetic differentiation measures showed either comparable levels between old and young populations (G" ST) or inconsistency among three species (cGD). The age difference of the two populations did not explain their genetic differentiation. Synthesis: We found restricted evidence that forest herb populations with different ages differ in their genetic structure, indicating that populations of different ages can reach a similar genetic structure within decades and thus persist in the long term after habitat disturbance. Despite their distinct breeding systems and associated pollinators, the three studied species exhibited partly similar genetic patterns, suggesting that their common characteristics, such as being slow colonizers or their ability to propagate vegetatively, are important in determining their long-term response to land-cover change.

Evaluating factors affecting species detection using passive acoustic monitoring in neotropical forests: a playback experiment

ABSTRACT Passive acoustic monitoring (PAM) has become a popular approach for terrestrial species monitoring. Studies determining detection ranges and predictors of detection probability are needed for accurate ecological modelling based on PAM data. We conducted a playback experiment to evaluate factors affecting call detectability in a neotropical forest. We used Geoffroy´s spider monkeys as a model species and broadcast their contact calls at seven distances from autonomous recording units (ARUs) positioned at different heights, in forest patches of different ages, and controlled for climate conditions during broadcasting trials. Using GLMMs (N = 1,342 data points), we found that call detectability increased the smaller the difference between the ARU and speaker height. We further found detection range to be wider the younger a surveyed forest patch is. To test whether these effects were related to structural signal characteristics, we included vocalisations from seven sympatric species in the experiment (N = 9,394). We found peak frequency to modulate the effect of ARU height difference, and peak frequency and bandwidth to modulate the effect of forest age on call detectability. Our study sheds light on factors influencing acoustic signal detectability and emphasises the need to consider climatic and habitat variables when designing PAM programmes.

Moth community responses to woodland creation: The influence of woodland age, patch characteristics and landscape attributes

AbstractAimLarge‐scale habitat creation is crucial to mitigate the current ecological crisis, but scientific evidence on its effects on biodiversity is scarce. Here, we assess how assemblages of a biodiverse group (moths) develop over time in habitat creation sites. We use temperate woodlands as a case study, and compare species assemblages in restored and mature habitat patches. We also identify local‐ and landscape‐level attributes associated with high species richness and abundance.LocationCentral Scotland, United Kingdom.MethodsWe surveyed moths in a chronosequence of 79 temperate woodland patches encompassing woodland creation sites (20–160 years old) and mature “ancient” woodlands (250+ years old). We used structural equation models, generalized linear models and ordination techniques to quantify moth community responses to woodland creation, and degree of similarity to moth assemblages in ancient woodlands.ResultsWoodland creation sites harboured large numbers of moth species (212), were dominated by woodland generalists and had high species turnover. Moth abundance and diversity increased with woodland connectivity. Macromoths were more abundant and diverse in younger woodlands; micromoth specialists occurred more frequently in older woodland creation sites. Ancient woodlands had similar moth abundance/richness than woodland creation sites (except for fewer macromoth woodland specialist species), but their species composition was somewhat different. Patterns of beta diversity (low nestedness) indicated that moth species in woodland creation sites are not simply subsets of species in ancient woodlands.Main conclusionsTo benefit moth communities, woodland creation sites should be structurally diverse and in close proximity to other woodlands. At the landscape scale, a mosaic of woodland patches of different ages is likely to increase moth beta (and consequently gamma) diversity. Ancient woodlands and woodland creation sites each host substantial proportions of “unique” species; individual woodland patches contain distinctive moth assemblages and should be protected and valued for their contribution to regional moth diversity.

Modelling the productivity of Siberian larch forests from Landsat NDVI time series in fragmented forest stands of the Mongolian forest-steppe

The monitoring of the spatial and temporal dynamics of vegetation productivity is important in the context of carbon sequestration by terrestrial ecosystems from the atmosphere. The accessibility of the full archive of medium-resolution earth observation data for multiple decades dramatically improved the potential of remote sensing to support global climate change and terrestrial carbon cycle studies. We investigated a dense time series of multi-sensor Landsat Normalized Difference Vegetation Index (NDVI) data at the southern fringe of the boreal forests in the Mongolian forest-steppe with regard to the ability to capture the annual variability in radial stemwood increment and thus forest productivity. Forest productivity was assessed from dendrochronological series of Siberian larch (Larix sibirica) from 15 plots in forest patches of different ages and stand sizes. The results revealed a strong correlation between the maximum growing season NDVI of forest sites and tree ring width over an observation period of 20 years. This relationship was independent of the forest stand size and of the landscape’s forest-to-grassland ratio. We conclude from the consistent findings of our case study that the maximum growing season NDVI can be used for retrospective modelling of forest productivity over larger areas. The usefulness of grassland NDVI as a proxy for forest NDVI to monitor forest productivity in semi-arid areas could only partially be confirmed. Spatial and temporal inconsistencies between forest and grassland NDVI are a consequence of different physiological and ecological vegetation properties. Due to coarse spatial resolution of available satellite data, previous studies were not able to account for small-scaled land-cover patches like fragmented forest in the forest-steppe. Landsat satellite-time series were able to separate those effects and thus may contribute to a better understanding of the impact of global climate change on natural ecosystems.

Abrupt fragmentation thresholds of eight zonal forest types in mainland Spain

This study quantifies patchiness of eight types of zonal forests in three biogeographic regions of mainland Spain (Atlantic, Alpine and Mediterranean) which together occupy 1,726,578 ha. Their dominant species and European Habitat Type codes (EU Directive 92/43 EEC) are: Fagus sylvatica (9120, 9130 and 9150), Quercus robur and Q. pyrenaica (9230), Q. suber (9330), Pinus uncinata (9430), P. nigra ssp. salzmannii (9530) and P. pinea (subset of 9540). We applied the Korcak’s exponent B, which describes a hyperbolic relationship between the cumulative frequency of the number of patches and their sizes. The objectives were: 1) detect possible patch size intervals in which B varies significantly, explicitly identifying area thresholds, and 2) contribute to development of a robust forest mass fragmentation indicator. Exponent B was found by segmented regression analysis. The vector data were extracted from a filtered version of the Spanish Forest Map 1:50,000 (1997–2006). After validating the procedure by applying it to a previously published dataset, we found that in all cases the patch size range could be split into two significant intervals around relatively small threshold areas of 27–101 ha. In the one on the left, the rate at which relatively large patches become less abundant was always very slow (B = 0.017–0.094). After this threshold had been passed, the rate increased abruptly (B = 1.100–2.590). Both this high fragmentation and its lack of parsimony were unexpected in zonal forest types. General interpretations converge to the coexistence of forest patches of different ages due to human pressure events.

Abiotic, present-day and historical effects on species, functional and phylogenetic diversity in dry grasslands of different age.

Many grasslands have disappeared over the last century as a result of anthropogenic land use intensification, while new patches are emerging through abandonment of arable fields. Here, we compared species (SD), functional (FD) and phylogenetic (PD) (alpha) diversity among 272 dry grassland patches of two age-classes: old and new, with the new patches being dry grasslands established on previous intensively managed fields during the last 30 years. We first compared SD, FD and PD, between patches of different age. Then, we performed generalized linear models to determine the influence of abiotic, present-day and historical landscape configuration variables on SD, FD and PD. By measuring abiotic variables, we explained the effect of environmental filtering on species diversity, whereas the present-day and historical landscape configuration variables were included to describe how the spatial and temporal configuration of the patches influence patterns of species. Finally, we applied partial regressions to explore the relative importance of abiotic, present-day and historical variables in explaining the diversity metrics and how this varies between patches of different ages. We found higher SD in the old compared to the new patches, but no changes in FD and PD. SD was mostly affected by abiotic and present-day landscape configuration variables in the new and the old patches, respectively. In the new patches, historical variables explained variation in the FD, while present-day variables explained the PD. In the old patches, historical variables accounted for most of the variation in both FD and PD. Our evidence suggests that the relative importance of assembly processes has changed over time, showing that environmental filtering and changes in the landscape configuration prevented the establishment of species in the new patches. However, the loss of species (i.e. SD) is not necessarily linked to a loss of functions and evolutionary potential.

Effects of host species, environmental filtering and forest age on community assembly of ectomycorrhizal fungi in fragmented forests

Abstract Understanding the assembly of biological communities in space and time is a major goal in community ecology. While most studies have focused on community assembly patterns in macro-organisms, there are comparatively few studies on micro-organisms. Here, we investigated how communities of ectomycorrhizal (EcM) fungi assemble in fragmented forests. We used a space-for-time substitution as an alternative for long-term studies to investigate variation in EcM fungal communities in three host species collected from 41 forest patches of different ages. Metabarcoding of root samples revealed that community composition was affected by a combination of host plant, soil variables, and forest age. While there were no clear effects of forest age on EcM fungal communities in early-successional tree species alder and hawthorn, forest age did affect the EcM fungal communities in hazel, which is typically associated with ancient forest. EcM fungal communities in early-successional species were affected mostly by soil conditions.

Germination and seedling establishment of Norway spruce (Picea abies) after clear-cutting is affected by timing of soil scarification

Natural regeneration of Norway spruce (Picea abies (L.) Karst.) is a relatively common practice in Norway on medium to low site indices. However, seedling establishment is often hampered by rapid regrowth of competing vegetation in scarified patches. The aim of our study was to examine the effect of coordinating scarification towards an expected seed-fall, by studying germination and seedling establishment in scarified patches of different age (fresh, one- and two-year-old). The experiment was conducted in two stands in southeast Norway that were clear-cut in 2007. Scarification was applied to subplots in autumn 2008–2010. To simulate seed-fall, seeds were sown in fresh scarification patches in spring 2009–2011, in one-year-old patches in 2010 and 2011, and in two-year-old patches in 2011. Both germination and seedling survival were negatively affected by the age of the scarified patches. Germination was higher, and mortality lower, at the small fern woodland site, compared with the bilberry woodland site. Sowing in fresh patches also resulted in increased height and root collar diameter of the seedlings compared with sowing in older patches. It is likely that the competing vegetation both on the site and in the scarification patches affected the growth of the seedlings. In conclusion, the age of the scarified patches affected both germination and mortality, as well as early growth of the seedlings.

Producción, descomposición e invertebrados del mantillo en varias etapas de la sucesión en Ciudad Colón, Costa Rica

This work reports the changes occurring in production and decomposition of litter and its invertebrate fauna during succession in a pasture and three forest patches of different ages (11,21 and 30 years) in Ciudad Colon, Costa Rica, at 800 m above sea level, with an annual rainfall of about 2000 mm, and a mean annual temperature of 23 C. There is a severe dry season of approximately 6 months. Litter production increases with the age of the forest, 65% and 87%, respectively, in the 11- and 21 -year old forests as compared with that of the 30-year-old patch. The rate of decomposition is very similar in the two older forests. The invertebrate population is more diverse and stable in the 30 year-old forest, but an increment of this fauna was observed in the three forests when litter moisture increased with the first rains. Mites, ants and collembola were the most abundant groups found in the litter of the three forests and in the pasture.

How to publish a good journal in plant community ecology?

We are pleased to publish the 27th volume of the Journal of Vegetation Science (JVS). Since its inception in 1990, JVS has been increasingly recognized by readers as a leading publication in the field of plant community ecology. This is reflected in its steadily increasing impact factor according to Thomson Reuters Web of Science. The current IF for JVS is 3.709, well comparable to many other established ecological journals. Although a high impact factor is definitely not our central goal, it is, nonetheless, an indication of visibility and recognition of the research published in the journal.

The effects of plant traits on species' responses to present and historical patch configurations and patch age

Patch configuration is viewed as an important factor affecting the distributions of plant species. Although a number of studies have explored the relationship between plant life‐history traits and species’ distributions in fragmented landscapes, the effect of individual traits on the dependence of species on historical versus current landscape configurations remains unclear.We identified the extent to which present (2000s) and historical (1843, 1954, 1980s) patch configurations (area and connectivity) and patch age affected the distributions of 99 species inhabiting dry calcareous grasslands. We used traits related to dispersal, survival, growth and habitat preferences to explain the dependence of 60 of these species on present and historical configurations, and the age of grassland patches.We found that most of the species had an affinity to currently or historically large, older and more isolated patches. This suggests that many dry grassland species are not in equilibrium with the current landscape, as their distributions still reflect past landscape structures. Rapidly growing species with higher seed bank longevity and nutrient requirements primarily occur in young, large grassland patches whereas species with the opposite traits occur in older, historically large and currently more isolated smaller patches. We hypothesise that patch quality is the reason why different species occupy patches of different age. Species occupying young, large patches commonly disperse by endozoochory. By contrast, no dispersal trait is associated with species occupying old, usually isolated patches. Our results suggest that species occupying old patches are exposed to higher potential risk of extinction, as their distributions are probably limited by the low number and connectivity of available suitable patches and poor dispersal ability. We thus suggest that the dynamics of these species can effectively be supported by improving the quality of young grassland patches.

Effects of time since fire on birds in a plant diversity hotspot

Global changes are influencing fire regimes in many parts of the world. In the Fynbos plant diversity hotspot (Cape Floristic Region, South Africa), fire frequency has increased in protected areas where the mean fire interval went from 12–19 to 6–9 years between 1970 and 2000. Fire is one of the main drivers of plant diversity in the Cape Floristic Region. Too frequent fires threaten the persistence of slow-maturing plant species, and such insights have led to the adoption of fire management principles based on plant responses. The effects of fire on Fynbos fauna are much more poorly understood, and have not generally been considered in depth in Fynbos conservation policies, planning or management. We assessed the response of bird communities to long-term fire-induced vegetation changes using space-for-time substitution. We studied bird communities, vegetation structure and plant functional composition in 84 Fynbos plots burnt between two and 18 years before. Ten of the 14 bird species analysed showed a significant change in their abundance with time since fire. We observed a significant species turnover along the post-fire succession due to changes both in vegetation structure and plant functional composition, with a characteristic shift from non-Fynbos specialists and granivorous species to Fynbos specialists and nectarivorous species.If current trends of increasing fire frequency continue, Fynbos endemic birds such as nectarivores may become vulnerable. Conservation management should thus aim more carefully to maintain mosaics of Fynbos patches of different ages. Future research needs to estimate the proportion of vegetation of different ages and patch sizes needed to support dependent fauna, particularly endemics.

Low gains in ecosystem carbon with woody plant encroachment in a South African savanna

Abstract:Total ecosystem carbon storage has frequently been found to increase with woody encroachment in savannas. However the loss of grass roots associated with woody encroachment can lead to a decrease in below-ground carbon storage which is not compensated for by an increase in above-ground carbon. To investigate how the extent of total woody cover affected ecosystem carbon, soil and above-ground carbon storage along eight thicket–savanna and five forest–grassland boundaries were measured. To investigate whether changes in soil carbon concentrations were related to the percentage of C4 (grass) roots to total roots and root quantity and quality, we measured fine-root biomass, root C : N ratios, root N, and % C4 roots at three different depths across thicket patches of different ages (n = 189). Forests contained significantly more carbon than adjacent grasslands in both above-ground carbon (mean difference 12.1 kg m−2) and in the top 100 cm of the soil (mean difference 4.54 kg m−2). Thickets contained significantly more above-ground carbon than adjacent savannas (3.33 kg m−2) but no significant differences in soil carbon were evident. Total fine-root biomass appeared to be more important than root quality (root C : N) in determining soil carbon concentrations during the encroachment process (i.e. in thicket of different ages). Similarly for thickets, the % C4 roots had no significant effect on soil carbon concentrations. In conclusion, thicket invading into open savanna vegetation did not lead to significant gains in ecosystem carbon at this study site. Significant gains were only evident in mature forest, suggesting that the process may take place very slowly.

Groupings of life‐history traits are associated with distribution of forest plant species in a fragmented landscape

AbstractQuestions: 1. Do relationships among forest plant traits correspond to dispersability‐persistence trade‐offs or other inter‐trait correlations found in the literature? 2. Do species groups delineated by trait similarity, differ in occurrence in ancient vs. new forests or isolated vs more continuous forest patches? 3. Are these patterns consistent for different forest types?Location: Central Belgium, near Leuven.Methods: We investigate the distributions of a large set of plant traits and combinations among all forest species occurring in patches with varying forest continuity and isolation. Through calculation of Gower's similarity index and subsequent clustering,‘emergent’ species groups are delineated. Then, the relative occurrence of these different groups in forest patches of different age and size, sustaining different forest types (alluvial vs. Quercion), and having different isolation status is compared through multivariate GLM analysis.Results: Correlations among several life history traits point towards trade‐offs of dispersability and fecundity vs. longevity. We distinguished three species groups: 1= mainly shrubs or climbers with fleshy or wind dispersed fruits and high dispersal potential; 2 = dominated by small, mainly vegetatively reproducing herbs; 3 = with spring flowering herbs with large seeds and mainly unassisted dispersal. Relative occurrence of these groups was significantly affected by forest age, area, isolation and forest type. Separate analyses for alluvial and Quercion forests indicated that the relative importance of these factors may differ, depending on forest type and species group. Both forest continuity and isolation are important in restricting the relative occurrence of forest species in alluvial forests, whatever their group membership. In Quercion forests forest patch area was the primary determinant of relative occurrence of species groups.Conclusions: It is very important to preserve the actual forest area including the spatial setting and the dispersal infrastructure within the landscape. Next, forest connectivity may be restored, but it is inherently a long process.

Groupings of life-history traits are associated with distribution of forest plant species in a fragmented landscape

Questions: 1. Do relationships among forest plant traits correspond to dispersability-persistence trade-offs or other inter-trait correlations found in the literature? 2. Do species groups delineated by trait similarity, differ in occurrence in ancient vs. new forests or isolated vs more continuous forest patches? 3. Are these patterns consistent for different forest types? Location: Central Belgium, near Leuven. Methods: We investigate the distributions of a large set of plant traits and combinations among all forest species occurring in patches with varying forest continuity and isolation. Through calculation of Gower's similarity index and subsequent clustering,‘emergent’ species groups are delineated. Then, the relative occurrence of these different groups in forest patches of different age and size, sustaining different forest types (alluvial vs. Quercion), and having different isolation status is compared through multivariate GLM analysis. Results: Correlations among several life history traits point towards trade-offs of dispersability and fecundity vs. longevity. We distinguished three species groups: 1= mainly shrubs or climbers with fleshy or wind dispersed fruits and high dispersal potential; 2 = dominated by small, mainly vegetatively reproducing herbs; 3 = with spring flowering herbs with large seeds and mainly unassisted dispersal. Relative occurrence of these groups was significantly affected by forest age, area, isolation and forest type. Separate analyses for alluvial and Quercion forests indicated that the relative importance of these factors may differ, depending on forest type and species group. Both forest continuity and isolation are important in restricting the relative occurrence of forest species in alluvial forests, whatever their group membership. In Quercion forests forest patch area was the primary determinant of relative occurrence of species groups. Conclusions: It is very important to preserve the actual forest area including the spatial setting and the dispersal infrastructure within the landscape. Next, forest connectivity may be restored, but it is inherently a long process.

Periodic local disturbance in host–parasitoid metapopulations: host suppression and parasitoid persistence

Within many agricultural systems, insect pests and their natural enemies are forced to persist as a metapopulation, continuously recolonizing patches following disturbance through harvesting or spraying with insecticides. Despite the need to understand factors influencing biocontrol success, few theoretical studies of host–parasitoid interactions have examined the potential impact of local disturbance within a metapopulation framework. Here, we add periodic local mortality to series of classical host–parasitoid models to examine its effect on host suppression and parasitoid persistence. Using a deterministic lattice model, we show that despite the wide range of complex dynamics generated at the patch level, the region wide pattern of disturbance is the key factor influencing host suppression. The level of host suppression achieved can be understood in terms of both the strength of density dependent parasitism, and the relative amounts of host and parasitoid mixing amongst patches of different ages. Local dispersal among patches is sufficient to ensure coexistence of the host and parasitoid, though persistence is not necessarily associated with the formation of self-organized spatial structures reported in previous studies. Finally, a stochastic version of the model is developed, in order to highlight how the effects of demographic stochasticity may influence biocontrol success in highly disturbed agricultural systems.

Influence of environmental and spatial variables on regional distribution of forest plant species in a fragmented and changing landscape

During the past several centuries, forests in Europe and large parts of North America have been subject to extensive forest clearance. The last several decades, however, numerous new forest patches have been established onto former agricultural land. As a result, the present forest area often consists of a mixture of small forest patches of different age, area, habitat quality and connectivity embedded within a hostile agricultural landscape. In these patchy landscapes, distribution patterns of plant species may be affected by both regional and local factors, although the relative importance of both is still poorly understood. In this study, we investigated distribution patterns of 113 forest plant species in a fragmented landscape. Species abundances at the regional scale conformed to a clearly unimodal abundance distribution which we believe to be related to 1) environmental heterogeneity due to succession and 2) inequality in migration rates. Patch incidence was significantly related to life form, which in turn was correlated to seed mass and dispersal mechanism. Multiple logistic regressions showed that presence/absence of 59 species studied was significantly affected by patch connectivity, patch area and age for 35, 30 and 34 species, respectively. The results of this study indicate that distribution patterns of forest plant species are influenced by both local and regional factors. Moreover, they also demonstrate that next to spatial aspects of fragmentation, temporal patterns of landscape change may have far‐reaching effects on presence/absence patterns of plant species and therefore should be incorporated in studies dealing with regional population structures of plants.

The Report of the Ecological Society of America Committee on the Scientific Basis for Ecosystem Management

The Report of the Ecological Society of America Committee on the Scientific Basis for Ecosystem Management

Multiple Stable States and Models of Riparian Vegetation Succession on the Animas River, Colorado

AbstractNatural and human disturbances have had fundamentally different effects on ecosystems. Range scientists have proposed a new successional model, a “state‐and‐transition model,”which recognizes the possibility of multiple stable states in vegetation. This paper assesses this model via an investigation of the influence of fluvial processes and landforms on variation in a mosaic of riparian vegetation patches of different ages on a river reach in montane southwestern Colorado. We sampled the composition of herbaceous and shrubby plants in 67 contiguous patches along a 6 km reach of the river, measured 14 environmental variables in each patch, and then analyzed the relationship of the vegetation and environmental gradients using correspondence analysis. The variation in vegetation correlates most higly with the age of the patch, surficial‐sediment size, and soil development, which represent different aspects of a gradient in time since last disturbance by floods. A consistent pattern of post‐flood succession is not evident in the trends in species richness, mean percent cover, and species composition. The evidence suggests that exceptional floods in 1911 and 1927 altered fundamentally the physical environment on newly exposed bars. As a result, succession slowed and its trajectory may have been redirected toward a new stable state. While this may be a case of multiple stable states in a natural ecosystem, we suggest that such cases are rare in natural ecosystems. We also argue that proponents of state‐and‐transition models conclude wrongly that these models imply that managers can, or should, choose the desired state based primarily on human uses instead of managing for the potential natural vegetation. That decision is a societal one that should not be implicit in a successional model.