The effects of data aggregation on long-term projections of forest stands development

Forest management planning often relies on Airborne Laser Scanning(ALS)-based Forest Management Inventories(FMIs)for sustainable and efficient decision-making.Employing the area-based(ABA)approach,these inventories estimate forest characteristics for grid cell areas(pixels),which are then usually summarized at the stand level.Using the ALS-based high-resolution Norwegian Forest Resource Maps(16 m×16 m pixel resolution)alongside with stand-level growth and yield models,this study explores the impact of three levels of pixel aggregation(standlevel,stand-level with species strata,and pixel-level)on projected stand development.The results indicate significant differences in the projected outputs based on the aggregation level.Notably,the most substantial difference in estimated volume occurred between stand-level and pixel-level aggregation,ranging from-301 to+253 m^(3)·ha^(-1)for single stands.The differences were,on average,higher for broadleaves than for spruce and pine dominated stands,and for mixed stands and stands with higher variability than for pure and homogenous stands.In conclusion,this research underscores the critical role of input data resolution in forest planning and management,emphasizing the need for improved data collection practices to ensure sustainable forest management.

Changes in Avian Spring Arrival Dates of 115 Species in the Central Appalachians over 127 Years

Global climate change affects many facets of avian ecology, such as shifts in breeding phenology and migration patterns. Migrating bird species respond to changes in climate by shifting their temporal patterns of spring migration. However, variation in species’ responses exists based on various life history traits, which exposes some species to an increased risk of phenological mismatch. This study examined the spring arrival dates of 115 migrating species over 127 years (1889-2015) using archival sources in West Virginia, USA, making this research unique in the length of study, the high number of species studied, and the historical crowd-sourced observations analyzed. Of the 115 taxa, 45 showed significant negative slopes of spring arrival dates (arriving earlier in the spring) plotted against the year. In contrast, only nine species showed positive slopes (arriving later in the spring), albeit non-significant. The average advance of spring arrival date for all species was 1.7 days per decade, and an advance of 2.6 days per decade in species that showed significance. Arrival dates were associated with increasing spring temperatures—for each 1˚C increase, the arrival date advanced by 0.81 days/decade. Several life history traits were linked to species that advanced their first arrival dates, including a shorter distance migrated to reach wintering grounds, increasing populations, and foraging habitat. Most avian species are advancing their spring arrival dates in response to climate change. However, the implications of earlier spring arrival are unclear. We draw attention to shifts in arrival dates and wintering ranges, leading to a possible increase in overwintering in the mid-latitudes of North America.

Characteristics of typhoon disturbed gaps in an old-growth tropical montane rainforest in Hainan Island, China

Disturbances that create gaps can shape the structure and function of forests. However, such disturbance regimes in Asian tropical montane rainforests remain largely unquantified. Least studied are typhoon disturbances that are attributable to climate change. We investigated gap characteristics in terms of size, age, and gap-maker to quantify the gap disturbance regimes in an intact old-growth tropical montane rainforest on Hainan Island, China. The intensity of typhoons has increased since 1949, and typhoon winds blow mostly (45.5%) from the northeast corner of Hainan Island, resulting in a higher frequency of gaps in the northeast. A total of 221 gap-makers (trees that fell to create canopy gaps) and 53 gaps were observed in a 3.16 ha old-growth rainforest. Most canopy gaps (85%) were < 200 m(2). The average size of canopy gaps was smaller in the rainforest than in other tropical forests, while the average size of expanded gaps was similar to those in other tropical forests. The maximum age of gaps was 23.5 years indicating that gaps had more rapid turnover than other parts of tropical forests. The frequency distribution of gap-makers followed a lognormal distribution with a distinctive peak at three gap-makers, which was different from the inverse J-shaped curve typical of other tropical forests. Gaps were recorded mainly on slopes between 20A degrees and 35A degrees and wood density of gap-makers was between 0.6 and 0.7 g cm(-3). Our results suggest that small-scale disturbance was the dominant agent of gap formation in this old-growth rainforest that is subject to increasing typhoon disturbances.

Tree species richness enhances stand productivity while stand structure can have opposite effects, based on forest inventory data from Germany and the United States of America

Background： in recent studies, mixed forests were found to be more productive than monocultures with everything else remaining the same. Methods： To find out if this productivity is caused by tree species richness, by a more heterogeneous stand structure or both, we analyzed the effects of forest structure and tree species richness on stand productivity, based on inventory data of temperate forests in the United States of America and Germany. Results： Having accounted for effects such as tree size and stand density, we found that： （I） tree species richness increased stand productivity in both countries while the effect of tree size heterogeneity on productivity was negative in Germany but positive in the USA; （11） productivity was highest at sites with an intermediate amount of precipitation; and （111） growth limitations due water scarcity or low temperature may enhance structural heterogeneity. Conclusions： In the context of forest ecosystem goods and services, as well as future sustainable forest resource management, the associated implications would be：

Does a shift in shade tolerance as suggested by seedling morphology explain differences in regeneration success of northern red oak in native and introduced ranges?

Across North America, forests dominated by Quercus rubra L. (northern red oak), a moderately shade-tolerant tree species, are undergoing successional replacement by shade-tolerant competitors. Under closed canopies, Q. rubra seedlings are unable to compete with these shade-tolerant species and do not recruit to upper forest strata. In Europe, natural regeneration of introduced Q. rubra is often successful despite the absence of fire, which promotes regeneration in the native range. Considering that understorey light availability is a major factor affecting recruitment of seedlings, we hypothesized that Q. rubra seedlings are more shade tolerant in the introduced range than in the native range. Morphological traits and biomass allocation patterns of seedlings indicative of shade tolerance were compared for Q. rubra and three co-occurring native species in two closed-canopy forests in the native range (Ontario, Canada) and introduced range (Baden-Württemburg, Germany). In the native range, Q. rubra allocated a greater proportion of biomass to roots, while in the introduced range, growth and allocation patterns favored the development of leaves. Q. rubra seedlings had greater annual increases in height, diameter and biomass in the introduced range. Q. rubra seedlings in the introduced range were also younger;however, they had a mean area per leaf and a total leaf area per seedling that were five times greater than seedlings in the native range. Such differences in morphological traits and allocation patterns support the hypothesis that Q. rubra expresses greater shade tolerance in the introduced range, and that natural regeneration of Q. rubra is not as limited by shade as in the native range. The ability of Q. rubra seedlings to grow faster under closed canopies in Europe may explain the discrepancy in regeneration success of this species in native and introduced ranges. Future research should confirm findings of this study over a greater geographical range in native and introduced ecosystems, and examine the genetic and environmental bases of observed differences in plant traits.

Evaluation of habitat quality for selected wildlife species associated with island back channels

The islands and associated back channels on the Ohio River, USA, are believed to provide critical habitat features for several wildlife species. However, few studies have quantitatively evaluated habitat quality in these areas. Our main objective was to evaluate the habitat quality of back and main channel areas for several species using habitat suitability index (HSI) models. To test the effectiveness of these models, we attempted to relate HSI scores and the variables measured for each model with measures of relative abundance for the model species. The mean belted kingfisher (Ceryle alcyon) HSI was greater on the main than back channel. However, the model failed to predict kingfisher abundance. The mean reproduction component of the great blue heron (Ardea herodias) HSI, total common muskrat (Ondatra zibethicus) HSI, winter cover component of the snapping turtle (Chelydra serpentina) HSI, and brood-rearing component of the wood duck (Aix sponsa) HSI were all greater on the back than main channel, and were positively related with the relative abundance of each species. We found that island back channels provide characteristics not found elsewhere on the Ohio River and warrant conservation as important riparian wildlife habitat. The effectiveness of using HSI models to predict species abundance on the river was mixed. Modifications to several of the models are needed to improve their use on the Ohio River and, likely, other large rivers.

Dendroclimatic analysis of white pine (Pinus strobus L.)using long-term provenance test sites across eastern North America

Background: The main objective of this study was to examine the climatic sensitivity of the radial growth response of 13 eastern white pine(Pinus strobus L.) provenances planted at seven test sites throughout the northern part of the species’ native distribution in eastern North America.Methods: The test sites(i.e., Wabeno, Wisconsin, USA; Manistique, Michigan, USA; Pine River, Michigan, USA; Newaygo,Michigan, USA; Turkey Point, Ontario, Canada; Ganaraska, Ontario, Canada; and Orono, Maine, USA) examined in this study were part of a range-wide white pine provenance trial established in the early 1960 s in the eastern United States and Canada. Principal components analysis(PCA) was used to examine the main modes of variation [first(PC1) and second(PC2) principal component axes] in the standardized radial growth indices of the provenances at each test site.The year scores for PC1 and PC2 were examined in relation to an array of test site climate variables using multiple regression analysis to examine the commonality of growth response across all provenances to the climate of each test site. Provenance loadings on PC1 and PC2 were correlated with geographic parameters(i.e., latitude, longitude,elevation) and a suite of biophysical parameters associated with provenance origin location.Results: The amount of variation in radial growth explained by PC1 and PC2 ranged from 43.4% to 89.6%. Dendroclimatic models revealed that white pine radial growth responses to climate were complex and differed among sites. The key dendroclimatic relationships observed included sensitivity to high temperature in winter and summer, cold temperature in the spring and fal(i.e., beginning and end of the growing season), summer moisture stress, potential sensitivity to storminduced damage in spring and fal, and both positive and negative effects of higher winter snowfal. Separation of the loadings of provenances on principal component axes was mainly associated with temperature-related bioclimatic parameters of provenance origin at 5 of the 7 test sites close to the climate influence of the Great Lakes(i.e., Wabeno,Manistique, Pine River, Newaygo, and Turkey Point). In contrast, differences in radial growth response to climate at the Ganaraska test site, were driven more by precipitation-related bioclimatic parameters of the provenance origin location while radial growth at the easternmost Orono test site was independent of bioclimate at the provenance origin location.Conclusions: Study results suggest that genetic adaptation to temperature and precipitation regime may significantly influence radial growth performance of white pine populations selected for use in assisted migration programs to better adapt white pine to a future climate.

Assessing stand structure in successional stages of dark coniferous forests in western Sichuan, China

Subalpine dark coniferous forests in the western Sichuan Province of China play an important role in the hydrological processes in the upper reaches of the Yangtze River. Second-growth forests, with different stand successional stages, have developed as a result of logging over the past 50 years. Forest cover and stand structure changed greatly with concomitant degradation of forest ecosystem functions. To understand how the stand structures of the second-growth forests change during the stand succession process, we analyzed stand structure characteristics and an old-growth state index of the bamboo and moss-forest types. We found that stand structure at the young successional stage featured one-third of the structure characteristics of the old-growth dark coniferous forests,while the structure of the medium-aged stage had reached half the structure of the old-growth state. The two forest types were similar in the rate of development at the young successional stage but differed at the medium-aged stage;the moss-forest type had more advanced development than the bamboo-forest type at the medium-aged successional stage.

Sedimentation in Mountain Streams: A Review of Methods of Measurement

The goal of this review paper is to provide a list of methods and devices used to measure sediment accumulation in wadeable streams dominated by cobble and gravel substrate. Quantitative measures of stream sedimentation are useful to monitor and study anthropogenic impacts on stream biota, and stream sedimentation is measurable with multiple sampling methods. Evaluation of sedimentation can be made by measuring the concentration of suspended sediment, or turbidity, and by determining the amount of deposited sediment, or sedimentation on the streambed. Measurements of deposited sediments are more time consuming and labor intensive than measurements of suspended sediments. Traditional techniques for characterizing sediment composition in streams include core sampling, the shovel method, visual estimation along transects, and sediment traps. This paper provides a comprehensive review of methodology, devices that can be used, and techniques for processing and analyzing samples collected to aid researchers in choosing study design and equipment.

ASIAN CARP EXPANSION IN THE MISSISSIPPI RIVER:FOCUSING ON THE LEADING EDGE OF THE INVASION FRONT

Asian carp are expanding their range throughout the Mississippi River; however, abundance is thought to be highest in reaches within close proximity to the Illinois River. In the Mississippi River, Lock and Dam 19(L&D 19) at Keokuk, Iowa is the primary barrier to slow the expansion upstream. As Asian carp abundance increases below L&D 19, it is important to investigate potential means of control(i.e., reduction through harvest and barriers) that will prevent complete invasion of the Mississippi River above L&D 19. Silver Carp and Bighead Carp were collected below L&D 19, a subsample were implanted with ultrasonic transmitters to evaluate passage through the lock chamber and the remainder were used to determine population dynamics at the leading edge of invasion. Although the dam portion of the structure poses a complete barrier to upstream expansion, we documented lock chamber passage demonstrating the lock chamber has the capability to provide passage upstream. Based on the results of the population assessment, in order to induce recruitment overfishing at this leading edge of invasion, Asian carp will need to be intensively harvested at 300 mm and larger. The combination of commercial fishing efforts and research investigating ways to prevent passage upstream must be employed.

Impacts of Anthropogenic Stresses on Biodiversity： A Case Study of Lumbini, Nepal

Biodiversity conservation denotes the protection, management and utilization of resources available on or below the surface of the earth. The sustainability of biodiversity resources rely on the ecological balance. A sound planning based on ecological background and human needs provide successful management of natural resources. The study area, Lumbini harbors rich biodiversity and provide significant habitats for several species of birds, mammals, herpetofauna and fish. There are four major habitat types in Lumbini area-farmland, forest, grassland and wetland. The resources outside the Lumbini Development Trust and surrounding villages have already depleted due to excessive human interference in natural resources. Lumbini and its vicinity are rich in natural resources but poor in terms of infrastructure and delivery of services. The areas are losing natural wealth to pay for development. Rural areas around Lumbini are confronted with worsening poverty, ill health, illiteracy and continuing deterioration of natural ecosystems on which the local residents depend for their well-being. The only way to assure a safer and more prosperous future in Lumbini area is to deal with environment and development issues in a balanced manner. This research work attested that the local stakeholders feel ownership on people centered conservation.

Ponderosa Pine Seed Source Test in Nebraska in the Central Great Plains of the United States

Ponderosa pine (Pinus ponderosa Laws) has been planted widely in the Great Plains for wind breaks. A 1968 study recommended using material from south-central South Dakota and north-central Nebraska. A second test to further delineate seed sources (families) from numerous collection sites in this region was established in 1986. This paper reports results for survival, height, diameter, and D2H (diameter squared X height) measurements at 15 years. Results identify a wide range of suitable families within the region. A majority of the tested sources performed well, thus verifying the original recommendations.

The Relationships among Community Type, Peat Layer Thickness, Belowground Carbon Storage and Habitat Age of Mangrove Forests in Pohnpei Island, Micronesia

This paper quantifies the relationships among community type, peat layer thickness and habitat age of the mangrove forests in Pohnpei Island, Micronesia and provides a discussion concerning the primary succession and the belowground carbon storage of the main mangrove community types. The ages of the habitat were estimated from a relationship between the thickness of the mangrove peat layer and the formative period, which was decided by calibrated radiocarbon ages. Mangrove communities in the coral reef type habitat were generally arranged in the following order, from seaward to landward: 1) the Rhizophora stylosa or Sonneratia alba community (I or II communities), 2) the typical subunit of the S. alba subcommunity of the Rhizophora apiculata— Bruguiera gymnorrhiza community (III(2)a subunit) and 3) the Xylocarpus granatum subunit of the same subcommunity of the same community (III(2)b subunit). Their habitat ages were estimated to be younger than 460 years, between 360 and 1070 years and between 860 and 2300 years, respectively. Based on these results and other evidences such as photosynthetic characteristics and pollen analysis derived from the previous studies, the primary succession was inferred to have progressed in the order mentioned above. Belowground stored carbon for the main community types in the coral reef type habitat were estimated to be less than 370 t C ha-1 for the I and the II communities, between 290 and 860 t C ha-1 for the III(2)a subunit and between 700 and 1850 t C ha-1 for the III(2)b subunit.

Assessing forest understory biomass in northwest Florida (USA) and its potential to meet the state energy needs

A stratified random sampling approach was employed to quantify total biomass across prevalent non-commercial forest understory species found in six counties of northwest Florida, USA. The moisture content （wet basis） and calorific values of these species were also measured. Total green biomass from forest understory species was estimated to be around 12 million metric tons, mostly comprised of Cliftonia monophylla （titi, buckwheat tree） and Cyrilla racemiflora （white titi, swamp titi）. This understory forest biomass would be sufficient to generate about 28.8 million GJ of electricity or 1589.25 million liters of ethanol. A need was identified to determine the inventory of forest understory biomass at the state level and assess the overall sustainability of utilizing forest understory biomass for bioenergy.

Riparian and Riverine Wildlife Response to a Newly Created Bridge Crossing

Construction of man-made objects such as roads and bridges can influence wildlife presence and abundance. We investtigated waterbirds, songbirds, anurans, turtles, small mammals, and furbearers along the Ohio River, WV, at a new bridge crossing, a 45-year old bridge, and 1 or 2 islands with no bridge and at 3 distances from the bridge or center point at each site (0 m,100 m, and300 m). We sampled 19 waterbird, 60 songbird, 7 anuran, 5 turtle, 9 small mammal, and 4 furbearer species. Great blue heron (Ardea herodias) abundances were greater at the site with no bridge. Songbird composition differed among sites and between transects under and away from the bridge with higher abundances or association of rock pigeon (Columba livia) and cliff swallow (Petrochelidon pyrrhonota) under the bridges and lower abundances ofCarolinawren (Thryothorus ludovicianus) and common yellowthroat (Geothlypis trichas) under the bridges. Total small mammal abundance, diversity, and richness were lower under the new bridge compared to other sites and distances. We conclude that overall the new bridge is causing minimal relative abundance impacts to wildlife. However, great blue heron abundance may be altered due to noise and activity from the presence of the bridge and minor short-term impacts to some songbirds and small mammals directly under the bridge in the form of habitat conversion, fragmentation, and loss due to removal of vegetation is apparent.

Forest Fringe Communities Participation in Forest Reserve Sustainability in Ghana

The paper investigated the forest fringe community’s participation in forest reserve sustainability in Ghana using Brong-Ahafo Region of Ghana as a case study. The key issues examined are the forest reserve management strategies, stakeholder’s participation and livelihood activities of forest fringe communities. Two stage sampling technique was used to sample forty-two respondents for the study. A structured questionnaire in an interview form was used to solicit information from the respondents. Descriptive statistics was used to analyse the data. The results of the study indicate that there is a management plan for the forest reserve but Forest Services Division (FSD) does not follow its prescriptions strictly, the involvement of Forest Fringe Communities (FFCs) by FSD in the management of the forest reserve was insignificant and evidence of FSD not establishing income generating activity for FFCs livelihood sustenance. It is therefore recommended that community members should be empowered to play the role of co-managers of the forest reserve and there should be regular visit and interaction between FSD and the FFCs.

Microhabitat use by white-footed mice Peromyscus leucopus in forested and old-field habitats occupied by Morrow's honeysuckle Lonicera morrowii

We quantified microhabitat use by white-footed mice Peromyscus leucopus in forest and old-field habitats occupied by Morrow＇ s honeysuckle Lonicera morrowii, an invasive exotic shrub imported from Japan. Microhabitat characteristics were compared between trails used by mice （ n = 124） and randomly selected trails （ n = 127） in 4 study plots located at Fort Necessity National Battlefield, Farmington, Pennsylvania, USA. We compared 10 mierohabitat variables between used and random trails using non-metric multidimensional scaling （NMDS） and classification and regression tree （CART） analysis. Trails used by mice were statistically different from randomly selected trails in both forested plots （ P 〈 0. 008） and old-field plots （ P 〈 0. 001 ）. In the forested plots, trails of white-footed mice were more often associated with a greater percent cover （% cover） of coarse woody debris （CWD） than were randomly selected trails. In the old-field plots, mouse trails were commonly characterized by having a lower % cover of exotic herbaceous vegetation, a greater % cover of shrubs, and a greater % cover of Morrow＇ s honeysuckle than randomly selected trails. Our study indicates that white-footed mice do not move randomly and prefer areas of high structural complexity, thereby showing significant microhabitat preference. The preference of white-footed mice for areas with a relatively high percent cover of Morrow＇s honeysuckle could 1 ） be a factor in the aggressive nature of the exotic honeysuckle shrub＇s spread throughout the Battlefield or 2） cause the shrub to spread even faster into adjacent areas not yet occupied by Morrow＇ s honeysuckle

Examining approaches for modeling individual tree growth response to thinning in Norway spruce

Using periodic measurements from permanent plots in non-thinned and thinned Norway spruce(Picea abies(L.)H.Karst.)stands in Norway,individual-tree growth models were developed to predict annual diameter increment,height increment,and height to crown base increment.Based on long-term data across a range of thinning regimes and stand conditions,alternative approaches for modeling response to treatment were assessed.Dynamic thinning response functions in the form of multiplicative modifiers that predict no effect at the time of thinning,a rapid increase followed by an early maximum before the effect gradually declines to zero could not be fitted to initially derived baseline models without thinning related predictors.However,alternative approaches were used and found to perform well.Specifically,indicator variables representing varying time periods after thinning were statistically significant and behaved in a robust manner as well as consistent with general expectations.In addition,they improved overall prediction accuracy when incorporated as fixed effects into the baseline models for diameter and height to crown base increment.Further,more simply,including exponentially decreasing multiplicative thinning response functions improved prediction accuracy for height increment and height to crown base increment.Irrespective of studied attribute and modelling approach,improvement in performance of these extended models was relatively limited when compared to the corresponding baseline models and more pronounced in trees from thinned stands.We conclude that the largely varying and often multi-year measurement intervals of the periodic data used in this study likely prevented the development of more sophisticated thinning response functions.However,based on the evaluation of the final models’overall performance such complex response functions may not to be necessary to reliably predict individual tree growth after thinning for certain conditions or species,which should be further considered in future analyses of similar nature.

AGE-0 SILVER CARP AND GIZZARD SHAD DAILY GROWTH AND HATCH TIMING IN THE MIDDLE MISSISSIPPI RIVER

The establishment of a highly efficient planktivore, Silver carp(Hypophthalmichthys molitrix), in the Mississippi River Basin has been documented as having negative impacts on native planktivore populations. Silver carp have the potential, to alter the trophic food web through negative interactions with native planktivores in large river systems. Due to increasing Silver carp ranges, interactions between Silver carp and other native planktivores is likely to increase. One abundant native planktivore that is often found in similar habitats as Silver carp is Gizzard shad(Dorosoma cepedianum). Potential competition for resources exists because of overlapping habitat use and forage. Given the similarities between these two planktivores, we sought to evaluate daily growth rates and determine hatch dates of age-0 Silver carp and Gizzard shad in the Middle Mississippi River. Silver carp and Gizzard shad were collected from the Middle Mississippi River using an electrified surface trawl from June through September with sizes ranging from 21—65 mm total length for Gizzard shad and 24—85 mm total length for Silver carp. A sample of age-0 fish(n=697) was collected at the end of the growing season including 292 Gizzard shad and 405 Silver carp. Size structure(total length in mm) of Silver carp(49.05±0.41; ± SE) was significantly greater(T= –16.43, df=695, P<0.001) than Gizzard shad(38.95 ± 0.45). Hatch dates were similar between Silver carp(July 26 th to August 18 th) and Gizzard shad(July 28 th to August 19 th). Growth of Silver carp(2.24 mm per day) was significantly greater(P<0.001,T= –11.1, df=82) than Gizzard shad(1.72 mm per day). Mortality was similar between Silver carp(28.1%)and Gizzard shad(25.1%) at this early life stage. The faster growth rates in Silver carp result in Silver carp entering the winter season larger in size with likely an increased capacity to consume plankton and decreased predation ultimately leading to higher recruitment. Knowing that there exists an overlap between Silver carp and Gizzard shad diets and habitat could alone call cause for concern. Adding that spawning occurs at a similar time and Silver carp have the ability to outgrow Gizzard shad early in life leads to major concerns about food web balance. Knowing that invasive planktivores have already shown to alter food webs in aquatic systems in North America, extra caution should be taken.

A RAPID ASSESSMENT APPROACH FOR EVALUATING SILVER CARP GENDER

Silver carp Hypophthalmichthys molitrix were introduced into the U.S. to control water quality in aquaculture ponds. From this point of origin, silver carp escaped into nearby rivers through multiple flood events. Because of their documented negative effects on native biota, silver carp have been labeled as problematic. Therefore, evaluating the biology and ecology of these non-indigenous species is critical. Multiple parameters are needed to evaluate silver carp populations(length, weight, age, and sex). Furthermore, developing methods for rapidly acquiring these data are needed. In relation to sex determination, sexual dimorphism was observed where males exhibit distinct pectoral fin ray features. Specifically, males have pronounced ridges or a "rough patch" on the dorsal surface of pectoral fins. Therefore, to test if this was an applicable way of determining silver carp gender; silver carp were collected from Midwestern U.S. rivers(N=2015) in the fall of 2011(N=870), spring of 2012(N=645), winter of 2013—2014(N=202) and summer2015(N=323) via electrofishing. For each silver carp collected, presence(e.g., rough patch) or absence(e.g.,smooth) of pronounced ridges on the top side of the pectoral fins was recorded, and an incision was made in the body cavity to identify gender. Based on the results of our evaluation, gender was correctly identified over99% of the time(2006 out of 2015) based on the pectoral fin dimorphism. In the samples taken in the winter of 2013—2014 and summer of 2015, accuracy for silver carp shorter than 300 mm and longer than 800 mm was 53.7%(19 out of 41) while accuracy for silver carp between 300 mm and 800 mm total length was 98.9%(289 out of 292). This study provides a rapid assessment approach for evaluating silver carp gender.