Showing papers on "Ecosystem published in 1986"
TL;DR: While vascular plant leaves have received most attention in stream research, there is growing recognition that wood is also important and the direct contribution of wood to stream energy budgets is minimal because wood is resistant to breakdown.
Abstract: That major flows of energy occur along detrital pathways in all ecosystems is a recent recognition. In freshwater ecosystems, detritus or dead organic matter (217) has two possible sources: autochthonous detritus generated within the ecosystem and allochthonous detritus generated externally. This review is concerned with the breakdown of vascular plant detritus whether autochthonous, from aquatic vascular plants, or allochthonous, derived from riparian trees and herbs. The importance to the energetics of streams of vascular plant material from riparian vegetation was recognized in early studies by Nelson & Scott (184), Egglishaw (85), and Minshall (175). Organic matter budgets for various streams have provided quantitative data to support these early observations (96, 132, 182, 254). However, many low-order streams that lack canopies of riparian vegetation may be dominated by autochthonous primary production of nonvascular plant origin. (72, 176). Theoretical models (256) predict increasing importance of autochthonous production by periphyton and aquatic vascular plants for middle-order streams but less importance of these sources in very large streams, mainly due to light limitation. The relative dominance of allochthonous vs autochthonous sources has been shown to vary between stream systems and with local conditions within streams (72, 178). While vascular plant leaves have received most attention in stream research, there is growing recognition that wood is also important. The direct contribution of wood to stream energy budgets is minimal because wood is resistant to breakdown (e.g. 8, 251). However, woody debris is indirectly important because it creates habitat for aquatic organisms (5), promotes
1,581 citations
TL;DR: Variations in mineral cycling nonetheless follow coherent, explicable patterns in tropical forests, and the cycling of nitrogen, phosphorus, potassium, calcium, and magnesium are the best-studied soil-derived nutrients, and they are the nutrients most likely to limit primary production and other ecosystem functions.
Abstract: Early studies of nutrient cycling in moist tropical forests described productive forests rich in nutrients (98, 114, 176) in which rates of primary production and the amounts of nutrients cycled clearly exceeded those in temperate zone forests. Reviews of global-scale patterns in biomass, production, and nutrient cycling reported these results as representative of tropical forests (130, 175). At the same time, tropical forest soils were described as acid, infertile clays that harden irreversibly to "laterite" when cleared (106), or as bleached quartz sands low in mineral nutrients (88). This apparent paradox was crystallized by Whittaker (174) in the statement "The tropical rain forest thus has a relatively rich nutrient economy perched on a nutrient-poor substrate" (p. 271). Reviews of more recent research on overall patterns of mineral cycling in the tropics (78, 124), and of important components such as biomass (20, 21), litterfall nutrients (123, 164), and decomposition (5), clearly show that patterns of nutrient cycling in tropical forests are diverse. It makes no more sense to describe a 'typical' tropical forest than a 'typical' temperate forest (33, 151). Variations in mineral cycling nonetheless follow coherent, explicable patterns in tropical forests. Our purposes in undertaking this review are: (a) to illustrate the patterns of nutrient cycling in moist tropical forests; (b) to identify the mechanisms which regulate those patterns; and (c) to show how those patterns affect the productivity, physiology, and population biology of tropical forests and their large-scale linkages with aquatic ecosystems and the atmosphere. We emphasize the cycling of nitrogen, phosphorus, potassium, calcium, and magnesium; these are the best-studied soil-derived nutrients, and they are the nutrients most likely to limit primary production and other ecosystem functions.
1,498 citations
TL;DR: The ecosystem consequence of several common changes in submersed Macrophytes: replacement of vascular macrophytes by bryophytes during lake acidification; short-term biomass changes caused by invasions of adventive species, cultural eutrophication or macrophyte management; and changes in littoral grazers are considered.
1,198 citations
TL;DR: Relative impacts of bottom-up (producer controlled) and top-down (consumer controlled) forces on the biomass and size structure of five major components of freshwater pelagic systems were estimated.
Abstract: Relative impacts of bottom-up (producer controlled) and top-down (consumer controlled) forces on the biomass and size structure of five major components of freshwater pelagic systems (piscivores, p...
989 citations
TL;DR: In this article, a computer simulation that assembles a model ecosystem which links these biotic and abiotic interactions through equations that predict decomposition processes, actual evapo-transpiration, soil water balance, nutrient uptake, growth of trees, and light penetration through the canopy.
Abstract: The interactions between the biotic processes of reproduction, growth, and death and the abiotic processes which regulate temperature and water availability, and the interplay between the biotic and abiotic processes regulating N and light availabilities are important in the dynamics of forest ecosystems. We have developed a computer simulation that assembles a model ecosystem which links these biotic and abiotic interactions through equations that predict decomposition processes, actual evapo-transpiration, soil water balance, nutrient uptake, growth of trees, and light penetration through the canopy. The equations and parameters are derived directly from field studies and observations of forests in eastern North America, resulting in a model that can make accurate quantitative predictions of biomass accumulation, N availability, soil humus development and net primary production.
659 citations
TL;DR: In this article, the effects of beaver activity on several major ecosystem components and processes in boreal forest drainage networks in Quebec, Canada were investigated and it was shown that beavers act as a keystone species to alter hydrology, channel geomorphology, biogeochemical pathways, and community productivity.
Abstract: Beaver (Castor canadensis) alter the structure and dynamics of aquatic ecosystems with a minimum of direct energy or nutrient transfer. Through dam building and feeding activities, beaver act as a keystone species to alter hydrology, channel geomorphology, biogeochemical pathways, and community productivity. Here we consider the effects of beaver activity on several major ecosystem components and processes in boreal forest drainage networks in Quebec, Canada. The density of dams on the small streams (≤4th order) we studied average 10.6 dams/km; the streams retain up to 6500 m3 of sediment per dam, and the wetted surface area of the channel is increased up to several hundred—fold. Beaver are also active in large order streams (≥5th order), but their effects are most noticeable along riverbanks and in floodplains. Comparative carbon budgets per unit area for a riffle on 2nd order Beaver Creek and a beaver pond downstream show the pond receives only 42% of the carbon acquired by the riffle annually. However, because the pond has a surface area seven times greater than the riffle, it receives nearly twice as much carbon as the riffle per unit of channel length. Carbon in the pond has an estimated turnover time of °161 yr compared to ° 24yr for the riffle. Beaver ponds are important sites for organic matter processing; the stream metabolism index (SMI), a measure of ecosystem efficiency for the utilization or storage of organic inputs, is 1.63 for the pond compared to 0.30 for the riffle; the turnover length (S) for particulate carbon is 1.2 km for the pond compared to 8.0 km for the riffle. Beaver—induced alterations to the structure and function of streams suggest removal of beaver prior to 1900 AD had substantial effects on the dynamics of lotic ecosystems. Our results suggest that current concepts of the organization and diversity of unaltered stream ecosystems in North America should recognize the keystone role of beaver, as drainage networks with beaver are substantially different in their biogeochemical economies than those without beaver.
562 citations
TL;DR: Quantification and comparisons of the structure of open-water plankton communities from 25 inland lakes of Ontario, from the Laurentian Great Lakes Superior, Huron, St. Clair, Ontario, and Erie, an...
Abstract: Quantification and comparisons of the structure of open-water plankton communities from 25 inland lakes of Ontario, from the Laurentian Great Lakes Superior, Huron, St. Clair, Ontario, and Erie, an...
406 citations
TL;DR: In this article, a computer model was used to track the consequent changes in the carbon balance of nine wetland regions in the temperate zone of the United States and Europe.
Abstract: (1) Organic soil-wetlands, particularly those in the temperate zone, under natural conditions, are net carbon sinks and hence are important links in the global cycling of carbon dioxide and other atmospheric gases. Human alteration of wetlands has brought about shifts in the balance of carbon movement between the wetlands and the atmosphere. Because previous analyses have not fully considered these shifts, disturbance of carbon storage in organic soil-wetlands of the temperate zone has been analysed for the last two centuries and considered in relation to other sources of atmospheric CO2 from the biosphere. (2) Storage before recent disturbance is estimated as 57 to 83 Mt of carbon per year, over two-thirds of this in boreal peatlands. The total storage rate, lower than previous estimates, reflects accumulation rates of carbon of only 0.20 t ha-' yr-1 and less in the boreal zone where 90% of temperate organic soils are found. (3) Widespread drainage of organic soil-wetlands for agriculture has significantly altered the carbon balance. A computer model was used to track the consequent changes in the carbon balance of nine wetland regions. Drainage reduced or eliminated net carbon sinks, converting some wetlands into net carbon sources. Different regions thus can function as smaller carbon sinks, or as sources, depending on the extent of drainage. In either case a shift in carbon balance can be quantified. (4) The net carbon sink in Finland and the U.S.S.R. has been reduced by 21-33%, in Western European wetlands by nearly 50%, and in Central Europe the sink has been completely lost. Overall, by 1900 the temperate zone sink was reduced 28-38% by agricultural drainage alone. (5) By 1980 the total annual shift in carbon balance attributable to agricultural drainage was 63-85 Mt of carbon, 38% in Finland and U.S.S.R. wetlands, and 37% in Europe. Twenty-five percent of the shift occurred in North American wetlands south of the boreal zone. No apparent change occurred in boreal Canada and Alaskan wetlands. (6) Peat combustion for fuel released 32-39 Mt of carbon annually, nearly all in the U.S.S.R. A total of 590-700 Mt of carbon has been released from peat combustion since 1795, compared with a release of 4140-5600 Mt from agricultural drainage. (7) The aggregate shift in the carbon balance of temperate zone wetlands, when added to a far smaller shift from tropical wetlands, equalled 150-185 Mt of carbon in 1980 and 5711-6480 Mt since 1795. Despite occupying an area equivalent to only 2% of the world's tropical forest, the wetlands have experienced an annual shift in carbon balance 15-18% as great. Wetlands thus are seen on an area-specific basis to be concentrated sources of atmospheric CO2 which respond differently from those ecosystems assumed to have no net carbon exchange before disturbance.
396 citations
01 Jan 1986
TL;DR: It is argued that whole-system functional properties are better indicators of ecosystem status than is any aspect of species biology, and this point of view has been deplored but not unambiguous disproved.
Abstract: How important are individual species in controlling ecosystem properties? Many studies of ecosystem-level dynamics are conducted with little reference to the influences of the individual species within ecosystems. In some cases this dis-regard is explicit, and it is argued that whole-system functional properties are better indicators of ecosystem status than is any aspect of species biology (O’Neill et al. 1977). This point of view has been deplored but not unambiguously disproved (cf. Foin and Jain 1977; Mcintosh 1980).
338 citations
01 Jan 1986
TL;DR: In this article, the bryophytes of the boreal forest are interesting in that they may form a minor element of the community in terms of biomass, while simultaneously being a major element of cover and primary productivity.
Abstract: The bryophytes of the boreal forest are interesting in that they may form a minor element of the community in terms of biomass, while simultaneously being a major element in terms of cover and primary productivity. Even more importantly, the mosses may control ecosystem function through rapid nutrient uptake and through their effects on both the thermal environment of the soil and associated development of permafrost. Consequently, mosses can have major effects on vascular plant productivity and nutrient cycling in the ecosystem.
244 citations
TL;DR: In the size range from lO-4 to 10’ pg (carbon) body weight, the biomass of plankton in the euphotic layer of the North Pacific Central Gyre decreases as an allometric function of body weight.
Abstract: In the size range from lO-4 to 10’ pg (carbon) body weight, the biomass of plankton in the euphotic layer of the North Pacific Central Gyre decreases as an allometric function of body weight. Even in a steady state ecosystem such as that analyzed here, there is variability in space and time; this suggests that one must be careful in extrapolating the relation to less predictable marine areas. In obtaining dynamic information from biomass spectra, one must distinguish changes due to the flow of energy within the spectrum (growth, predation, reproduction) from changes due to emigration from or immigration into the spectrum of the particular area sampled, such as those due to the diel vertical migration of macrozooplankton in the largest size classes. As a basis for a “particle-size” approach to the description of pelagic ecosystems, it is important to establish whether there is a simple relation between the biomass (material per unit environmental volume or area) of organisms in any size category and the individual body size of those organisms. Although this approach has been applied mainly in aquatic ecology (in part because of the tendency for pelagic predators to swallow their prey whole but to be otherwise rather nonselective), Platt (1985) traced its origin to Elton (1927) and analyzed the reasons for the long hiatus until the 197Os, when this dormant approach began to develop with Odum’s (197 1, fig. 3.6) comparison between aquatic and terrestrial size distributions of biomass.
TL;DR: In this article, the authors document long-term change in benthic ecosystems and assess and manage the effects of such change on secondary production, particularly leading to commercially important food webs, pollutant transfer within the food web, and recycling of nutrients from the seafloor back to primary producers.
Abstract: Documentation of long-term change in benthic ecosystems is important for assessing and managing the effects of such change on: 1) secondary production, particularly leading to commercially important food webs, 2) pollutant transfer within the food web, 3) the ability of the ‘new’ assemblage to metabolically burn-off labile detritus that might otherwise accumulate, contributing to long-term hypoxia, and 4) recyling of nutrients from the seafloor back to primary producers.
01 Jan 1986
TL;DR: The first volume in the series "Ecological Studies" as mentioned in this paper provides an overview and synthesis of research on the structure and function of taiga forest ecosystems of interior Alaska, and discusses the nature of the taiga environment and covers climate, forest ecosystem distribution, natural regeneration of vegetation, and role of fire.
Abstract: This volume in the series ''Ecological Studies'' provides an overview and synthesis of research on the structure and function of taiga forest ecosystems of interior Alaska. The first section discusses the nature of the taiga environment and covers climate, forest ecosystem distribution, natural regeneration of vegetation, and the role of fire. The second edition focuses on environmental controls over organism activity with discussions on growth and nutrient use, nitrogen fixation, physiological ecology of mosses, and microbial activity and element availability. The final section considers environmental controls over ecosystem processes with discussions of processes, plant-animal interactions, and a model of forest growth and yield.
TL;DR: The best estimates to date suggest that nitrogen gas emission rates from undisturbed ecosystems typically range from > 1 to perhaps 10 or 20 kg N ha-1 yr-1 as discussed by the authors.
Abstract: There is increasing interest in the importance of nitrogen gas emissions from natural (non-agricultural) ecosystems with respect to local as well as global nitrogen budgets and with respect to the effects of nitrogen oxides on atmospheric ozone levels and global warming. The volatile forms of nitrogen of common interest are ammonia (NH3), nitrous oxide, (N2O), dinitrogen (N2), and NOx (principally NO + NO2). It is often difficult to attribute emissions of these compounds from soils to a single process because they are produced by a variety of common biogeochemical mechanisms. Although environmental conditions in the soil often appear to favor nitrogen gas emissions, the potential nitrogen gas emission rate from undisturbed ecosystems is rarely approached. The best estimates to date suggest that nitrogen gas emission rates from undisturbed ecosystems typically range from > 1 to perhaps 10 or 20 kg N ha-1 yr-1. Under certain conditions, however, emission rates may be much higher. For example, excreta from animals in grasslands may elevate ammonia volatilization up to 100 kg N ha-1 yr-1 depending on grazer density; tidal input of nutrients to coastal wetlands may support denitrification rates of several hundred kg N ha-1 yr-1 . Excepting such cases, gaseous nitrogen losses are probably a small component of the local nitrogen budget in most undisturbed ecosystems. However, emissions from undisturbed soils are an important component of the global source strengths for (N2O + N2), N2O and NOx (50%, 21%, and 10% respectively). Emission rates of N2O from natural ecosystems are higher than assumed previously by perhaps 10 times. Large-scale disturbance may have a stimulatory effect on nitrogen emission rates which could have important effects on global nitrogen budgets. There is a need for more sophisticated methods to account for natural temporal and spatial variations of emissions rates, to more accurately and precisely assess their global source strengths.
TL;DR: The livestock in aggregate provided a very broad, opportunistic, and temporally stable trophic niche that resulted from equitable use of all forage classes, and their mobility provided a means to exploit the entire region.
Abstract: (1) Seasonal patterns of forage selection, diet diversity, and habitat use were quantified for livestock managed by the Ngisonyoka Turkana in arid north-western Kenya by direct observation of free-ranging herds. The objective was to characterize the trophic niche segregation of livestock and their potential harvesting capacity for the heterogeneous vegetation resources of this ecosystem. (2) Cattle and cam Js were grazing and browsing specialists, respectively, while goats, sheep, and donkeys, were' generalists for both herbaceous and non-herbaceous vegetation. (3) Diet and habitat use were greatly influenced by season. Relative to brief rainy periods of resource abundance, long dry intervals of resource scarcity were times of reduced diet diversities (forage-class basis) for most species and greatly increased variation in habitat use. Livestock generally exhibited the greatest diet similarity in dry periods but were most segregated in terms of feeding habitats during these times. (4) The livestock in aggregate provided a very broad, opportunistic, and temporally stable trophic niche that resulted from equitable use of all forage classes, and their mobility provided a means to exploit the entire region. These attributes are essential for the persistence of nomads in this harsh, unpredictable environment, and are inimical to development tactics that serve to reduce livestock species diversity or restrict mobility.
TL;DR: Because of the low primary productivity of tundra vegetation, the export of organic carbon from the watershed via the river is a larger fraction of the total watershed net primary production than the 0.1–0.4% usually found for temperate rivers.
Abstract: The carbon cycle of the Kuparuk River, a meandering tundra stream, is dominated by inputs of eroding peat and leaching dissolved organic carbon from the tundra Net production of epilithic algae is about 13 g C∙m−2∙yr−1, an order of magnitude less than inputs of allochthonous particulate organic carbon and two orders of magnitude less than inputs of dissolved organic carbon The streamwater has a mean total organic carbon concentration of 68 mg∙L−1, and the annual export of organic carbon from the watershed is 2–3 t∙km−2∙yr−1; both are similar to the average for temperate streams However, because of the low primary productivity of tundra vegetation, the export of organic carbon from the watershed via the river is a larger fraction (2–6%) of the total watershed net primary production than the 01–04% usually found for temperate rivers
TL;DR: The species-rich sugar maple ecosystems exhibited a fourfold increase in potential nitrification compared with the species-poor sugar maple ecosystem, and nitrogen turnover on a landscape basis was virtually a...
Abstract: Potential nitrogen mineralization and nitrification were studied in three upland forest ecosystems to develop an understanding of nitrogen turnover on a landscape basis. The northern Michigan fores...
TL;DR: In this article, the authors developed measures of resilience of coastal sage scrub to fire in southern California: (1) elasticity (rate of recovery following disturbance), (2) amplitude (threshold of disturbance beyond which recovery to the original state no longer occurs), (3) malleability (extent of alteration of the new stable state from the original), and (4) damping (extending and duration of oscillation in an ecosystem parameter following disturbance).
Abstract: Measures of four components of resilience are developed and used to quantify the response of coastal sage scrub to fire in southern California: (1) elasticity (rate of recovery following disturbance), (2) amplitude (threshold of disturbance beyond which recovery to the original state no longer occurs), (3) malleability (extent of alteration of the new stable-state from the original) and (4) damping (extent and duration of oscillation in an ecosystem parameter following disturbance). Vegetation and soil properties measured before fire, and for the first 5–6 yr after fire on four coastal (Venturan association) and four inland (Riversidian association) sites of coastal sage were used to follow changes. In addition, results from a simulation model of post-fire succession in Venturan coastal sage scrub (the FINICS model of Malanson) were used to examine resilience behavior over a 200 yr period. Resilience behavior of coastal sage scrub is critically influenced by the presence of a competitive mix of inherently strongly and weakly resprouting species. Sites dominated by weak resprouters exhibit lower elasticity and less damping of year-to-year fluctuations in composition in the early post-fire years. Sites with a mixture of weak and strong resprouters have a lower threshold of disturbance (amplitude) before species extirpation occurs, a result intensified by a higher frequency of disturbance. Malleability is also greater in these systems under higher disturbance frequency.
TL;DR: Examination of FPOM samples with scanning electron microscopy revealed an abundance of wood-derived particles and studies of vertical distribution indicated that most fine wood is concentrated within 0.3 m of the stream bottom, while large wood is more evenly distributed up to 0.7‴m.
Abstract: The potential contribution of woody debris to fine particulate organic matter pools (0.45 μm ≤ FROM < 1 mm) was investigated in a coniferous forest stream ecosystem in western Oregon. The amount of...
01 Jan 1986
TL;DR: Germination ecology, patterns of growth and development, the relative competitiveness of species and their genetic composition are discussed with special reference to mediterranean-climate ecosystems, and seasonality of weeds is studied as a basis for prediction in agricultural or nature reserve management.
Abstract: The weed invasion process consists of three stages: introduction, colonisation and naturalisation. Specific features of mediterranean-climate ecosystems which allow some plants and not others to pass through these invasion stages include disturbance and the interaction between soil moisture levels and temperature. Germination ecology, patterns of growth and development, the relative competitiveness of species and their genetic composition are all biological attributes of invasive species which are discussed with special reference to mediterranean-climate ecosystems. These attributes of weeds influence management of both natural and agricultural systems in areas with a mediterranean climate, especially in relation to fire, disturbance and nutrient enrichment. Some ideas for future research are presented which focus on the invasion process itself, the dynamics of soil seed banks and on the study of seasonality of weeds as a basis for prediction in agricultural or nature reserve management.
TL;DR: This study showed that leaflitter banks held a diverse aquatic community of unexpectedly high biomass and supplied food and shelter and were available during the low water period when otherhabitats had dried out.
Abstract: A study of the benthic leaf litter community of the Tarumazinho, a centralAmazonian stream (03° S, 60° W) is presented This small tributary of the Rio Negro is of theblackwater type with a very low nutrient content The sampling stations were towards themouth of the tributary where it flowed through annually inundated forest and the work wascarried out during the low water season Previous studies concluded that these acid waters wereof very low productivity and held impoverished faunas However, this study showed that leaflitter banks held a diverse aquatic community of unexpectedly high biomass This was becausethe banks supplied food and shelter and were available during the low water period when otherhabitats had dried out The macrofauna was dominated by fish and shrimps From an examina-tion of gut contents a food web was produced Primary consumers were found to take mainlydetritus and fungi and it was concluded that allochthonous inputs were the main source ofenergy and nutrients No feeding specialists were found and all the predators took prey frommore than one trophic levelKEY WORDS: Amazonia, benthic community, blackwaters, freshwater ecology, food web, leaflitter, stream macrofaunaINTRODUCTION
TL;DR: In this paper, the authors evaluate seasonal and yearly variations in the mineralization of organic nitrogen to ammonium and then nitrification to nitrate in different ecosystems and suggest that nitrogen loss or other system properties correlated with one arbitrarily selected collection can be misleading.
Abstract: Patterns and amounts of nitrogen loss from disturbed ecosystems vary widely. The mineralization of organic nitrogen to ammonium and then nitrification to nitrate are important processes regulating nitrogen cycling rates and nitrogen losses. Nitrification is a significant process because of the production of the nitrate anion which is easily leached or denitrified. Most studies of these processes do not evaluate their seasonal and yearly variations. This study demonstrates that marked seasonal and yearly variations can occur in these processes in different ecosystems and suggests that nitrogen loss or other system properties correlated with one arbitrarily selected collection can be misleading. Spruce-fir and ponderosa pine ecosystems demonstrated little actual orpotential nitrification. Aspen and mixed conifer ecosystems demonstrated distinct seasonal patterns with increased rates of mineralization and nitrification during spring and summer months and a precipitous decline in both rates coincident with autumn foliage litterfall.
TL;DR: In this article, the authors report an assessment of the impact of Elodea, primarily focussing on the lake's response at the ecosystem level, and demonstrate that the resulting increased production of phytoplankton and macrophytes is due to the invader's superior utilization of space and sediment nutrient resources.
Journal Article•
TL;DR: Rougerie et al. as discussed by the authors introduced the concept of endo-upwelling géothermique, which is used in reef-building in the Tuamotu archipelago.
TL;DR: In this paper, the authors investigated the role of biological activity in regulating the fluxes of water and major ions in the lodgepole pine ecosystem and found that biological activity plays a critical role in regulating water fluxes.
Abstract: Despite the low productivity of forests in the Rocky Mountain environment, biological activity plays a critical role in regulating the fluxes of water and major ions. Moreover, although much of the landscape is dominated by monospecific stands of lodgepole pine, these fluxes vary markedly among sites. Concomitant differences in soil texture and forest structure appear to be important factors that induce this variation, a result of their influence on soil water storage capacity and the mobility of ionic solutes in mineral soil. Water and nitrogen availability, along with a cool, short growing season, limit the amount of leaves and roots that can develop, which in turn regulate water flows, the generation of protons consumed in soil weathering reactions, and the supplies of organic matter for heterotrophic organisms. New environmental stresses and increasing pressures for intensive forest management dictate that a more complete understanding of the controls of material fluxes in natural and man-dominated ecosystems is needed. The lodgepole pine ecosystem, while relatively simple, provides a representative example of the complexity that can be involved.
TL;DR: It may sometimes be optimal to reduce the harvested species even more following some perturbations, and the less impacted are primary (harvested) species relative to secondary species, the more likely it will be that a pre-recovery harvesting phase is necessary.
Journal Article•