Abstract Pilón (Hyeronima alchorneoides) is one of the native tree species with the greatest potential for cultivation in Costa Rica. At a national level, there is research on its silvicultural management, tree improvement, wood quality and others. However, there is a lack of an updated and complete technological guide for this species. Therefore, there is a need to compile and systematize the generated knowledge in recent years about this species, with the purpose of improving technical assistance to the producer or investors. One of the main issues and needs are the availability of reliable growth models for diameter and total height for this species. A database with more than 255 plots was used for the diameter growth and more than 150 plots recording the total height. The growth function fitted for the diameter was dap=1,4145+2,1381*Edad-0,0364*(Edad)^2. Meanwhile, for total height the fitted model was Ht=e^((3,9090-3,5510*√(1/Edad)), both models have a bias estimation of 20% for diameter and 18% for total height.

Resumen El pilón (Hyeronima alchorneoides) es una de las especies forestales nativas de mayor potencial de cultivo en Costa Rica. A nivel nacional, existen investigaciones en temas como manejo silvicultural, mejoramiento genético, calidad de la madera, entre otras. Sin embargo, no existe un paquete tecnológico actualizado y completo para esta especie. Por lo que surge la necesidad de actualizar los modelos de crecimiento de diámetro y altura para esta especie. Para este estudio se utilizó una base de datos con más de 255 parcelas para el crecimiento diamétrico y más de 150 para la altura total. La función de crecimiento para el diámetro ajustada fue dap=1,4145+2,1381*Edad-0,0364*(Edad)^2, mientras que, para la altura total, el modelo ajustado fue Ht=e^((3,9090-3,5510*√(1/Edad)), Ambos modelos registraron un sesgo de un 20% para la estimación del diámetro y un 18% para la estimación de la altura total.

Abstract The relative growth on spiny lobster Panulirus gracilis was analyzed a multimodel selection approach and Akaike information theory. In the carried out samples at the landing commercial of spiny lobster, at the south of Sinaloa, Mexico during season 2014 and 2015, and 2017 and 2018. In 298 female P. gracilis individuals were measures caparace length (CL) mm, total weight (W) g, and gonad maturity stages. The structure sizes between 54.6 to 103.1 mm CL. The organism minor size mature was 57.5 mm CL but maturity percent stages rise on larger sizes. The best model was broken stick (Wi = 65.09%) but also two segments has statistic support (Wi=34.87%). A differential relative growth in both models, coincident with a rise in the percent gonad maturity toward big sizes in P. gracilis.

Resumen Se analizó el crecimiento relativo de langosta espinosa Panulirus gracilis, con un enfoque de selección multimodelo y la teoría de la información de Akaike. Se realizaron muestreos en capturas comerciales de langosta espinosa del sur de Sinaloa, México entre las temporadas de pesca de 2014 y 2015 y, 2017 y 2018. En 298 hembras de P. gracilis se registró la longitud cefalotórax (LC) mm, peso total (PT) g y fase de madurez gonádica. La estructura de tallas varió de 54.6 a 103.1 mm de LC. Se observaron hembras maduras a partir de 57.5 mm de LC, con un incremento de proporción de madurez en tallas mayores. El mejor modelo fue Línea Rota (Wi=65.09%) y Dos Segmentos (Wi%=34.87). El cambio en el crecimiento relativo a la talla en ambos modelos, coincidió con un incremento en la proporción de madurez en tallas mayores a 60 mm de LC en P. gracilis.

ABSTRACT The use of native trees is necessary for land restoration and the sequestration of carbon that is stored in forest biomass production in Indonesia. Meanwhile, the biomass prediction model used for native tropical lowland trees of Indonesia is limited to only specific locations and focuses on aboveground biomass (AGB). This study aimed to select and evaluate potential native tree species for high biomass and to develop the best allometric model for estimating tree biomass production (AGB, belowground/BGB, and total/TB) in lowland ecosystems in Indonesia. Trees were selected using the following five criteria: nativeness, ecosystem type, morphological appearance, multipropagation ability, and economic value. Biomass content was quantified for 102 sample trees (56 trees aged 4 years and 46 trees aged 8 years), using the destructive method. Effective growth biomass and species ecological data indicated five species as potential trees for land restoration in tropical lowlands of Indonesia: Litsea garciae, Terminalia bellirica, Pterospermum javanicum, Anisoptera marginata, and Cananga odorata. The best allometric model of this study is highly recommended for implementation with native trees of tropical lowlands in Indonesia, especially those in early stages (less than 8 years). Meanwhile AGB. AGB . (AGB) AGB, (AGB belowgroundBGB belowground BGB belowground/BGB total/TB totalTB total TB criteria nativeness type appearance ability value 10 56 (5 years, , years) method garciae bellirica javanicum marginata odorata less years. 1 5 (

Abstract Diplopods are terrestrial arthropods important for the dynamics of terrestrial ecosystems. One of the reasons for that can be their low predation rate due to their defensive secretion. Thus, Orthoporus fuscipes, a species belonging to this group and endemic to northeastern Brazil, was investigated as to its population structure and chemical constituents of defensive secretion. The population structure showed that females are larger and have greater mass than do males, along with negative allometric growth between males and females. The defensive secretion hexane extract was submitted to fractionation using SiO2 open-column chromatography and the gas chromatographic coupled to mass spectrometric analysis was applied in the fraction possibilities to identify major fatty acid methyl esthers, along with minor alkanes, alkenes and fatty acids derivatives and the known quinoids 2-methoxy-3-methylhydroquinone, 2-methoxy-3-methyl-1,4-benzoquinone, 2,3-dimethoxy-1,4-benzoquinone and 2,3-dimethoxyhydroquinone. In addition, the cytochrome oxidase I sequence for the species was deposited for the first time. ecosystems Thus fuscipes Brazil SiO opencolumn open column esthers alkanes 2methoxy3methylhydroquinone, 2methoxy3methylhydroquinone methoxymethylhydroquinone 2 methoxy 3 methylhydroquinone, methylhydroquinone 2-methoxy-3-methylhydroquinone 2methoxy3methyl1,4benzoquinone, 2methoxy3methyl14benzoquinone methoxymethylbenzoquinone 1,4 benzoquinone, 1 4 benzoquinone 2-methoxy-3-methyl-1,4-benzoquinone 2,3dimethoxy1,4benzoquinone 23dimethoxy14benzoquinone dimethoxybenzoquinone 2,3 dimethoxy 2,3dimethoxyhydroquinone. 23dimethoxyhydroquinone dimethoxyhydroquinone dimethoxyhydroquinone. 2,3-dimethoxyhydroquinone addition time 2methoxy3methyl1 4benzoquinone 2methoxy3methyl1,4benzoquinone 14 1, 3dimethoxy1 23 2, 3dimethoxyhydroquinone 2,3dimethoxyhydroquinone methoxymethyl 2methoxy3methyl 3dimethoxy

Resumo O presente estudo examina as correlações entre 15 caracteres morfométricos e 10 caracteres merísticos e comprimento total (CT) de machos, fêmeas e sexos combinados de Alepes vari (Cuvier, 1833), coletados do porto de Karachi, West Wharf, na costa de Karachi. As análises estatísticas das relações de regressão linear mostraram, principalmente, correlações fortes (r ≥ 0,70; p < 0,05) entre o CT e a maioria dos caracteres morfométricos em machos, fêmeas e sexos combinados, exceto a altura da nadadeira peitoral e o comprimento da base da nadadeira pélvica, enquanto os caracteres merísticos foram constantes, indicando correlações fracas ou negativas (r ≤ 0,50; p > 0,05) com o CT. Portanto, de acordo com nossos resultados, existe uma relação direta entre o CT dos peixes e todos os caracteres morfométricos, que foram considerados os melhores indicadores de crescimento do padrão alométrico positivo em peixes. Além disso, a análise do teste t de duas amostras revelou (teste t; p > 0,05) que nenhum dimorfismo sexual foi relatado em A. vari. Assim, o presente estudo pode ser valioso na classificação sistemática, dimorfismo sexual e manejo dessa espécie na costa de Karachi.

Abstract The present study examines the correlations between fifteen morphometric and ten meristic characters and total length (TL) of males, females, and combined sexes of Alepes vari (Cuvier, 1833) collected from Karachi fish harbor, West Wharf of Karachi Coast. Statistical analyses of linear regression relationships show mostly strong correlations (r≥0.70; p<0.05) between total length (TL) and most morphometric characters in males, females, and combined sexes, except the height of pectoral-fin (PFH), and pelvic-fin base length (PelFL); whereas, meristic characters were found to be constant and indicate weak or negative type correlations (r≤0.50; p>0.05) with total length (TL). Hence, according to our present results, there is a direct relationship between the total length of fish and all morphometric characters, which were found to be the best indicators of positive allometric pattern growth in fish. Moreover, analysis of the 2-sample t-test revealed (t-test; p>0.05) that no sexual dimorphism was reported in Alepes vari. Thus, our present study could be valuable in systematic classification, sexual dimorphism, and management of this species on the Karachi coast.

ABSTRACT: In traditional sheep production systems in tropical regions, the evaluation and monitoring of animal growth are not commonly practiced. This is primarily attributed to the limited adoption of technology and the high costs associated with acquiring livestock scales. The present study developed equations to predict body weight of Pelibuey ewe lambs using a Body Volume (BV) formula. BW and BV were obtained from 85 ewe lambs. The models evaluated were as follows: 1) linear, 2) quadratic, 3) cubic, 4) allometric, 5) exponential and 6) logarithmic. In addition, the models’ predictive ability for BW was assessed by k-fold (k=10) cross-validation. The BW and BV were 20.60 ± 8.73 kg and 17.54 ± 7.89 dm3, respectively. The quadratic model showed the highest r2 and the lowest values of mean square error, root mean square error, and bayesian information criterion, while the k-fold cross-validation technique also had the highest r2 and the lowest values of mean squared prediction error and mean absolute error. The quadratic model was the best performing mathematical model for predicting BW of growing Pelibuey ewe lambs using BV. ABSTRACT regions practiced scales (BV formula 8 follows 1 linear 2 3 cubic 4 allometric 5 6 logarithmic addition kfold k fold k=10 k10 10 (k=10 crossvalidation. crossvalidation cross validation. validation 2060 20 60 20.6 873 73 8.7 1754 17 54 17.5 789 7 89 7.8 dm3 dm respectively r criterion k=1 k1 (k=1 206 20. 87 8. 175 17. 78 7. k= (k= (k

RESUMO: Nos sistemas tradicionais de produção de ovinos em regiões tropicais, a avaliação e monitoramento do crescimento dos animais não são práticas comuns. Isso se deve principalmente à adoção limitada de tecnologia e aos altos custos associados à aquisição de balanças para animais. O presente estudo teve como objetivo desenvolver equações para prever o peso corporal (PC) de borregas Pelibuey usando uma fórmula de Volume Corporal (VC). Foram obtidos dados de PC e VC de 85 borregas. Os modelos avaliados foram os seguintes: 1) linear, 2) quadrático, 3) cúbico, 4) alométrico, 5) exponencial e 6) logarítmico. Além disso, a capacidade preditiva dos modelos para o PC foi avaliada por meio de validação cruzada k-fold (k=10). O PC e VC foram 20,60 ± 8,73 kg e 17,54 ± 7,89 dm3, respectivamente. O modelo quadrático apresentou o maior r2 e os menores valores de erro do quadrático médio, raiz do erro do quadrático médio e critério de informação bayesiano, enquanto a técnica de validação cruzada k-fold também teve o maior r2 e os menores valores de erro quadrático médio de predição e erro médio absoluto. O modelo quadrático foi o melhor desempenho matemático para predizer o PC de cordeiras Pelibuey em crescimento usando o VC. RESUMO tropicais comuns (PC . (VC) 8 seguintes 1 linear 2 3 cúbico 4 alométrico 5 6 logarítmico disso kfold k fold k=10. k10 k=10 10 (k=10) 2060 20 60 20,6 873 73 8,7 1754 17 54 17,5 789 7 89 7,8 dm3 dm respectivamente r bayesiano absoluto (VC k1 k=1 (k=10 206 20, 87 8, 175 17, 78 7, k= (k=1 (k= (k

Resumo O estudo da biologia reprodutiva é uma abordagem importante na identificação de medidas de proteção para preservar os estoques pesqueiros, fornecendo dados essenciais para um sistema de gestão confiável que garanta o equilíbrio entre o meio ambiente e a economia. Neste estudo objetivou-se analisar a primeira maturidade sexual e o tipo de desova do peixe Conodon nobilis (Linnaeus, 1758) na costa amazônica, especificamente na região do Golfão Maranhense. Foram obtidos 360 exemplares provenientes da atividade de pesca comercial na comunidade pesqueira de Raposa-MA durante o período de janeiro a dezembro de 2021. Foram registrados dados biométricos e determinados os estágios de maturação gonadal por meio de análises macroscópicas (escala de maturação) e microscópicas (histologia). Foram determinados a razão sexual, a duração média da primeira maturação sexual e o tipo de desova. Foi registrado crescimento alométrico negativo para ambos os sexos, indicando maior aumento no comprimento do que no peso, sendo que o comprimento variou de 11 a 31.8 cm e a proporção sexual foi de 1 macho:1.5 fêmea. Foram observados indivíduos em todos os estágios de maturação durante todo o ano, com predomínio de indivíduos em capacidade reprodutiva e picos reprodutivos em janeiro, abril e maio, indicando que a espécie apresenta desovas múltiplas. O comprimento na primeira maturidade sexual (L50) para as fêmeas foi de 18.41 cm e para os machos foi de 18.91 cm. O conhecimento do tamanho médio na maturidade sexual pode ajudar a definir regulamentos apropriados para a pesca, garantindo que os indivíduos tenham a oportunidade de se reproduzir pelo menos uma vez antes de serem capturados. pesqueiros economia objetivouse objetivou Linnaeus, Linnaeus (Linnaeus 1758 amazônica Maranhense 36 RaposaMA Raposa MA 2021 escala histologia. histologia . (histologia) sexos peso 318 31 8 31. macho1.5 macho15 macho 1.5 5 macho:1. fêmea ano maio múltiplas L50 L (L50 1841 18 41 18.4 1891 91 18.9 capturados 175 3 202 (histologia macho1 macho1. 15 1. macho:1 L5 (L5 184 4 18. 189 9 17 20 macho: (L 2

Abstract The study of reproductive biology is an important tool in identifying protective measures to preserve fish stocks, providing essential data for a reliable management system that ensures a balance between the environment and the economy. This study aims to analyze the first sexual maturity and type of spawning of the fish Conodon nobilis (Linnaeus, 1758) on the Amazon coast, specifically in the Gulf Maranhense region. 360 specimens were obtained from commercial fishing activity in the community of Raposa-MA during the period from January to December 2021. Biometric data were recorded, and the gonadal maturation stages were determined through macro (maturation scale) and microscopic (histology) analyzes. Sex ratio, mean length of first sexual maturation and type of spawning were determined. Negative allometric growth was recorded for both sexes, indicating a greater increase in length than in weight, and the length varied from 11 to 31.8 cm and the sex ratio was 1 male:1.5 female. Individuals in all stages of maturation were observed throughout the year, with a predominance of individuals in spawning capacity and reproductive peaks in January, April and May, indicating that the species presents multiple spawning. The length at first sexual maturity (L50) for females was 18.41 cm and for males was 18.91 cm. Knowledge of the mean size at sexual maturity can help define appropriate regulations for fishing, ensuring that individuals have the opportunity to reproduce at least once before being captured. stocks economy Linnaeus, Linnaeus (Linnaeus 1758 coast region 36 RaposaMA Raposa MA 2021 scale histology (histology analyzes sexes weight 318 31 8 31. male1.5 male15 male 1.5 5 male:1. female year May L50 L (L50 1841 18 41 18.4 1891 91 18.9 captured 175 3 202 male1 male1. 15 1. male:1 L5 (L5 184 4 18. 189 9 17 20 male: (L 2

RESUMO A umbu-cajazeira (Spondias sp.) é uma frutífera nativa do semiárido brasileiro, com grande potencial ambiental e agrossocioeconômico para região. A determinação da área foliar (LA) é importante para compreensão das interações entre o crescimento, fisiologia, nutrição das plantas e o ambiente. Assim, o objetivo desta pesquisa é construir equações alométricas que estime de forma não destrutiva a área foliar umbu-cajazeira (Spondias sp.), considerando as dimensões dos folíolos (comprimento e largura). Os folíolos foram coletados de plantas matrizes de umbu-cajazeira (Spondias sp.), e medidos individualmente quanto ao comprimento (L), largura (W) e LA por meio de imagens digitalizadas. Estes dados foram submetidos à análise descritiva e de regressão. A LA foi estimada utilizando os modelos de regressão linear, potência e exponencial, baseados no L e W dos folíolos. O melhor modelo e equação foi escolhido com base nos critérios de seleção: coeficiente de determinação, índice de concordância de Willmott, raiz do erro quadrático médio e erro absoluto médio. O modelo potência utilizando LW apresentou a melhor equação 0.76 * LW0.98 para estimar a área dos folíolos de umbu-cajazeira (Spondias sp.). Este estudo fornece uma abordagem confiável, precisa, rápida e não destrutiva para pesquisadores e produtores do meio agronômico determinarem a LA da espécie. umbucajazeira umbu cajazeira Spondias sp. sp brasileiro região (LA crescimento fisiologia ambiente Assim sp., , largura. . largura) L, (L) (W digitalizadas linear exponencial seleção Willmott 076 0 76 0.7 LW098 LW0 98 LW0.9 sp.. confiável precisa espécie (L 07 7 0. LW09 9 LW0.

ABSTRACT The umbu-cajazeira (Spondias sp.) is a fruit tree native to the semi-arid of Brazil, with significant environmental and agro-socioeconomic potential for the region. Determining leaflet area (LA) is essential for understanding the interactions between plant growth, physiology, nutrition, and environment. Thus, this research aims to construct allometric equations that non-destructively estimate the umbu-cajazeira (Spondias sp.) leaflet area, considering the leaflet dimensions (length and width). The leaflets were collected from mother plants of umbu-cajazeira (Spondias sp.) and individually measured for length (L), width (W), and LA using digitized images. These data were submitted for descriptive and regression analysis. The LA was estimated using, linear power, and exponential regression models based on the L and W of the leaflets. The best model and equation were chosen based on the following selection criteria: coefficient of determination, Willmott agreement index, root mean square error, and mean absolute error. The power model using LW presented the best equation ŷ = 0.76 * LW0.98 to estimate the leaflet area of umbu-cajazeira (Spondias sp.). This study provides a reliable, accurate, fast, and non-destructive approach for agronomic researchers and growers to determine the LA of the species. umbucajazeira umbu cajazeira Spondias sp. sp semiarid semi arid Brazil agrosocioeconomic agro socioeconomic region (LA growth physiology nutrition environment Thus nondestructively non destructively width. . width) L, , (L) W, (W) images analysis criteria determination index error 076 0 76 0.7 LW098 LW0 98 LW0.9 sp.. reliable accurate fast nondestructive destructive species (L (W 07 7 0. LW09 9 LW0.

ABSTRACT Chrysanthemum (Dendranthema grandiflora) is the second most produced and commercialized ornamental plant in the world. Measuring leaf area through non-destructive methods is fundamental for studies on its growth and production. The estimation of leaf area by linear dimensions of the leaves can be a strategy for this purpose. The objective of this study was to find allometric equations to estimate the leaf area of chrysanthemum. The linear, linear without intercept, quadratic, cubic, power, and exponential regression models were used for the analysis. The choice of equations was based on the highest coefficients of determination. The non-destructive method using allometric models has accuracy for estimating the leaf area (LA) of chrysanthemum from the product between leaf length (L) and leaf width (W). The LA of chrysanthemum can be estimated using the equation ŷ = 0.6611*LW0.9490 (L - leaf length; W - leaf width). This equation will allow researchers and producers to determine leaf area non-destructively. Dendranthema grandiflora world nondestructive non destructive production purpose intercept quadratic cubic power analysis determination (LA L W. . (W) 06611LW09490 LW 0 6611 LW0 9490 0.6611*LW0.949 width. width) nondestructively. nondestructively destructively. destructively non-destructively (W 06611LW0949 661 949 0.6611*LW0.94 06611LW094 66 94 0.6611*LW0.9 06611LW09 6 9 0.6611*LW0. 06611LW0 0.6611*LW0 06611LW 0.6611*LW

RESUMO O crisântemo (Dendranthema grandiflora) é a segunda planta ornamental mais produzida e comercializada no mundo. A medição da área foliar por métodos não destrutivos é fundamental para estudos sobre seu crescimento e produção. A estimativa da área foliar por dimensões lineares das folhas pode ser uma estratégia para este fim. O objetivo deste estudo foi encontrar equações alométricas para estimar a área foliar do crisântemo. Os modelos de regressão linear, linear sem intercepto, quadrático, cúbico, potência e exponencial foram utilizados para a análise. A escolha das equações foi baseada nos maiores coeficientes de determinação. O método não destrutivo por meio de modelos alométricos tem acurácia para estimar a área foliar (AF) do crisântemo a partir do produto entre o comprimento da folha (C) e a largura da folha (L). A AF do crisântemo pode ser estimada pela equação ŷ = 0,6611*CL0,9490 (C - comprimento da folha; L - largura da folha). Essa equação permitirá que pesquisadores e produtores determinem a área foliar de forma não destrutiva. Dendranthema grandiflora mundo produção fim intercepto quadrático cúbico análise determinação (AF C L. . (L) 06611CL09490 CL 0 6611 CL0 9490 0,6611*CL0,949 folha. folha) destrutiva (L 06611CL0949 661 949 0,6611*CL0,94 06611CL094 66 94 0,6611*CL0,9 06611CL09 6 9 0,6611*CL0, 06611CL0 0,6611*CL0 06611CL 0,6611*CL

Abstract. The Peruvian moonfish (Selene peruviana) is an important fisheries resource that is landed in the main fishing harbors of Ecuador. At the local level, little information is available regarding the biology of this species, which hinders the development of management plans. The present study evaluates the reproductive characteristics of S. peruviana such as the size at sexual maturity and reproductive cycle. Specimens were obtained from artisanal and industrial catches from January 2017 to December 2018. The morphometric characteristics, sex, and maturity stage of 886 specimens were determined, and the gonadosomatic index (GSI), hepatosomatic index (HSI), and relative condition factor (Kn) were estimated. The length-weight relationship and length at sexual maturity (L50) were evaluated with an allometry equation and multi-model analyses, respectively. The mean capture size (total length, TL) was 23.62 cm for males and 22.97 cm for females. A sex ratio (M:F) of 0.70:1.00 (χ 2 = 26.28, P < 0.05) was obtained. The allometric factor of the length-weight relationship for both sexes (b) was 2.63 (t = 12.16, P < 0.05), and the coefficient of determination (r 2) was 0.89, which suggests that negative allometric growth was present. The L50 (TL) was estimated to be 22.61, 23.86, and 23.27 cm for males, females, and sexes combined, respectively. The monthly GSI, HSI, and Kn values were significantly different (K-W, P < 0.05) among study months. The maximum GSI values were observed in February and March, which constituted the period of highest reproductive activity. The HSI and Kn values exhibited similar trends. The size at sexual maturity was similar to the average catch size, which could indicate that S. peruviana is currently at the limit of its optimal catch size.

Resumen. El pez luna peruano, Selene peruviana, es un importante recurso desembarcado en las principales caletas pesqueras del Ecuador. A nivel local, existe poca información sobre la biología de esta especie, lo cual dificulta el desarrollo de planes de manejo. El presente estudio evalúa aspectos reproductivos de S. peruviana como la talla de madurez sexual y el ciclo reproductivo. Se obtuvieron muestras de capturas artesanales e industriales desde enero de 2017 hasta diciembre de 2018. Las características morfométricas, el sexo y la etapa de madurez de 886 especímenes fueron registrados y se estimó el índice gonadosomático (IGS), el índice hepatosomático (IHS) y el factor de condición relativo (Kn). La relación talla-peso y la talla de madurez sexual (L50) se evaluaron mediante la ecuación de alometría y análisis multimodelos, respectivamente. La talla media de captura (longitud total, LT) fue de 23.62 cm para los machos y 22.97 cm para las hembras. Se obtuvo una proporción de sexos (M:H) de 0.70:1.00 (χ2 = 26.28, P < 0.05). El factor alométrico de la relación longitud-peso para sexos combinados (b) fue 2.63 (t = 12.16, P < 0.05) y el coeficiente de determinación (r 2) fue 0.89, lo que sugiere una relación alométrica negativa. La L50 (LT) se estimó en 22.61, 23.86 y 23.27 cm para machos, hembras y sexos combinados, respectivamente. Los valores mensuales de IGS, IHS y Kn mostraron diferencias significativas (K-W, P < 0.05) entre los meses de estudio. Los valores máximos de IGS se observaron durante febrero y marzo, siendo el periodo de mayor actividad reproductiva. Los índices de IHS y Kn mostraron tendencias similares. La talla de madurez sexual fue similar a la talla media de captura, lo que podría indicar que S. peruviana se encuentra en el límite de su talla óptima de captura.

Abstract Quantifying the stocking of trees by means of allometric relationships within a stand favors better forest management, timber harvesting and helps to estimate losses due to illegal logging. The objective of this study was to represent in a quantitative way the allometric relationships between the variables of forest interest for Juniperus deppeana, a species of restricted use. Several allometric models were fitted with 1 096 pairs of data for stump (sd), normal (nd), and crown (cd) diameters, total height (Th), and volume (V) of trees of two growth conditions in natural forests of northern and western Tlaxcala State, Mexico. An average statistical improvement of 16.63 % in the explanation of sampling variability and a reduction of 18.53 % in bias were obtained by including the site as a random effect in the mixed-effects modeling approach. Validation of the estimates with data that are independent of the adjustment showed no significant differences. Consistently, the estimates of cd, Th, or V as a function of sd were conservative compared to when nd is used as an explanatory variable. Models n d = 2.5413 + 0.6778 × s d, R 2 =0.8187; c d = 0.4513 × n d 0.7733, R 2 =0.8195; T h = 1.3382 × n d 0.5039, R 2 =0.6281, and V = 0.0003 × n d 2.1005, R 2 =0.9563 proved to be reliable for reconstructing the mensuration characteristics of trees in stands affected by illegal logging activities, and for accurately quantifying the actual stock of this species' forests, they can be a reliable option for Juniperus deppeana forest management plans.

Resumen Cuantificar las existencias del arbolado por medio de las relaciones alométricas dentro de un rodal favorece una mejor gestión forestal, aprovechamiento maderable y ayuda a estimar las pérdidas por cortas clandestinas. El objetivo del presente estudio fue representar de manera cuantitativa las relaciones alométricas entre las variables de interés forestal para Juniperus deppeana, especie de aprovechamiento restringido. Se ajustaron distintos modelos alométricos con 1 096 pares de datos de los diámetros de tocón (dt), normal (dn) y de copa (dc), altura total (At) y volumen (V) de árboles de dos condiciones de crecimiento en bosques naturales del norte y poniente de Tlaxcala, México. Se obtuvo una mejora estadística promedio del 16.63 % en la explicación de la variabilidad muestral y una reducción de 18.53 % en el sesgo al incluir el sitio como efecto aleatorio en el enfoque de modelos de efectos mixtos. La validación de las estimaciones con datos independientes al ajuste no mostró diferencias significativas. De manera consistente, las estimaciones de dc, At o V en función del dt fueron conservadoras en comparación a cuando se utiliza como variable explicativa al dn. Los modelos d n = 2.5413 + 0.6778 × d t, R 2 =0.8187; d c = 0.4513 × d n 0.7733, R 2 =0.8195; A t = 1.3382 × d n 0.5039, R 2 =0.6281 y V = 0.0003 × d n 2.1005, R 2 =0.9563 evidenciaron ser confiables para reconstruir las características dasométricas del arbolado dentro de los rodales afectados por actividades de clandestinaje, y para cuantificar las existencias reales de los bosques de esta especie de forma precisa. Debido a lo anterior, pueden ser una alternativa confiable para la elaboración de planes de manejo forestal para Juniperus deppeana.

ABSTRACT Background. In Tamaulipas, Mexico, the Eastern oyster, Crassostrea virginica, is one of the most commercially important species. Goals. The population structure of C. virginica in the Tigre River and Laguna de San Andres in the State of Tamaulipas, Mexico, was determined. Methods. Oysters were collected from three banks from January to December 2022 using the quadrat-based method. The size structure (length, width, and weight), instar distribution, weight-length relationship, abundance, and biomass of C. virginica were determined. Results. In total, 2,277 organisms were collected. The representative size, in the three banks, occurred in a range of 43-65 mm in length. Significant differences were recorded in the width, length, and weight of the oysters collected, with Bank 1 and 2 organisms having the greatest length and weight. The three banks presented negative allometric growth when establishing a b value <3. No significant statistical difference was recorded in the number of recruits between the banks. A statistically significant difference was observed between banks in the average number of juveniles-preadults, adults, and adults with more than one reproductive. The abundance on the banks is below the established minimum number (> 200 oysters/m2). There is inadequate management of the resource on the three banks, where most oysters captured are below the size allowed for extraction. Conclusions. The structure shows that most of the C. virginica population is below the size allowed for its extraction, which is why the development of studies focused on the sustainable management of this species is suggested.

RESUMEN Antecedentes. En Tamaulipas, México, el ostión Crassostrea virginica es una de las especies de mayor importancia comercial. Objetivos. Se determinó la estructura poblacional de C. virginica en el Río Tigre y en la Laguna de San Andrés del Estado de Tamaulipas, México. Métodos. Se recolectaron ostiones en tres bancos de enero a diciembre del 2022, mediante el método basado en cuadrantes. Se determinó la estructura de tallas (largo, ancho y peso), distribución de estadios, relación peso-longitud, la abundancia y biomasa de C. virginica. Resultados. En total se recolectaron 2,277 organismos. La talla representativa, en los tres bancos en conjunto se presentó en un intervalo de 43-65 mm de largo. Se registraron diferencias significativas en el ancho, largo y peso de los ostiones recolectados, siendo los organismos del Banco 1 y 2 de mayor longitud y peso. Los tres bancos presentaron un crecimiento alométrico negativo al establecerse un valor b <3. En el número de reclutas entre los bancos no se registró diferencia estadística significativa. Se observó una diferencia estadística significativa entre los bancos en el número promedio de juveniles-preadultos, adultos y adultos con más de una reproducción. La abundancia en los bancos está por debajo del número mínimo establecido (> 200 ostras/m2). Se presenta inadecuado manejo del recurso en los tres bancos, donde la mayor parte capturada de ostiones se encuentra por debajo de la talla permitida para su extracción. Conclusión. La estructura de tallas muestra que la mayor parte de la población capturada de C. virginica se encuentra por debajo de la talla permitida para su extracción, por lo que se sugiere el desarrollo de estudios enfocados al manejo sustentable de esta especie.

Abstract The total height (Th) of bamboo culms is essential for inventories of volume, biomass, carbon stores, and products distribution. The high density of the canopy and the natural inclination of the upper part of the crown make its direct measurement of the field difficult. Allometric equations are a viable alternative to efficiently estimating the height as a function of the diameter at breast height (Dbh). The aim was to fit mathematical models Th-Dbh and select the best predictive capacity to estimate the Th of culms of Bambusa oldhamii Munro, Guadua aculeata Rupr. and Guadua angustifolia Kunth in the Northeastern Sierra of Puebla, Mexico. In the analysis, 101 pairs of Th-Dbh observations measured in 2019 were used, with which six allometric models and three growth models were fitted by non-linear regression. Nonlinear ordinary least squares techniques with indicator variables (NL-OLS-VI) and nonlinear mixed effects models (NL-MEM) were compared. The “nlme” package of the R software was used. We evaluated the models based on the adjusted coefficient of determination (R2 ad j ), the root mean square error (RMSE), and the mean bias (B). NL-OLS-VI explained 83.5% and NL-MEM 83.2% of the observed variability. The model with the best performance was the Logistic fitted with NL-OLS-VI (R2 ad j = 0.835, RMSE = 2.280 m y B = 0.005 m). The generated Th-Dbh model is workable to estimate the Th for culms of the three bamboo taxa with low errors.

Resumen La altura total (At) de los culmos de bambú es fundamental para realizar inventarios de volumen, biomasa, almacenes de carbono y distribución de productos. Su medición directa en campo se dificulta por la alta densidad del dosel y la inclinación natural de la parte alta de la copa. Las ecuaciones alométricas son una alternativa viable para estimar eficientemente la altura en función del diámetro normal (Dn). El objetivo fue ajustar modelos matemáticos At-Dn y seleccionar el de mejor capacidad predictiva para estimar la At de culmos de Bambusa oldhamii Munro, Guadua aculeata Rupr. y Guadua angustifolia Kunth en la Sierra Nororiental de Puebla, México. En el análisis se utilizaron 101 pares de observaciones At-Dn medidas en 2019 con los que se ajustaron por regresión no lineal seis modelos alométricos y tres de crecimiento. Se compararon las técnicas de mínimos cuadrados ordinarios no lineales con variables indicadoras (MCO-NL-VI) y modelos de efectos mixtos no lineales (MEM-NL), se usó la librería “nlme” del programa R. Los modelos se evaluaron con base en el coeficiente de determinación ajustado (R2 adj ), la raíz del error medio cuadrático (REMC) y el sesgo promedio (S). MCO-NL-VI explicó el 83.5% y MEM-NL el 83.2% de la variabilidad observada. El modelo con el mejor desempeño fue el Logístico ajustado con MCO-NL-VI (R2 adj = 0.835, REMC = 2.280 m y S = 0.005 m). El modelo At-Dn generado es factible para estimar la At para culmos de los tres taxones de bambú con errores bajos.

ABSTRACT The snail Trochita trochiformis is a mollusk captured on the coasts of Jalisco and Guerrero of the Mexican Pacific. Despite its importance in artisanal fisheries, information on its population parameters is still being determined. This research aimed to determine the diameter-weight relationship, sex ratio, cohorts, and growth of this species. Specimens were captured from October 2019 to September 2021. Shell diameter (Sd), total weight (TW), and the sex of the organisms were gathered from a total of 1763 females and 956 males. The sex ratio was 1.84:1, and the X2 test (P < 0.05) indicated significant differences. The Sd-Tw relationship for females and males was potential-type. The values of the allometry coefficient for both sexes were b = 2.61, b = 2.60 for females, and b = 2.62 for males. In all three cases, the t-Student test indicated negative allometric growth, which indicates that the species first grows in shell diameter, then in body weight. The ANCOVA did not show significant differences in the Sd-Tw relationships between sexes (P = 0.902). The Kolmogorov-Smirnov test applied to the Sd data showed differences between sexes (P < 0.001). In females, differences were observed in 71.5% by monthly comparisons, while in males, differences were found in 58.1%. Multinomial analysis showed three modal groups and 14 individual cohorts for both females and males. Case 2 of the Schnute model was the best for females (wi = 0.39) and males (wi = 0.53), showing sigmoidal Gompertz-type growth. The resulting growth curves showed that females exhibit accelerated growth concerning males and that both sexes reach their maximum size, 88.04 and 86.23 mm, respectively, at approximately 10 years of age.

Resumen: Las plantaciones forestales comerciales son una estrategia para proteger de la sobreexplotación a los bosques naturales, por lo que es importante, conocer las propiedades físicas de su madera. El objetivo del trabajo fue determinar la calidad de la madera con base en sus propiedades físicas, y la cantidad de biomasa en una plantación de Pinus engelmannii de 17 años. El diámetro normal y altura total se midió en todos los árboles encontrados en 20 sitios rectangulares de 3.0 x 6.0 m distribuidos en cuatro líneas. En cada sitio, con un taladro de Pressler se tomó un núcleo de crecimiento a 1.30 m de altura, en dos árboles dominantes. Las propiedades físicas, densidad básica (DB), contenido de humedad (CH), contracciones volumétricas totales (CVT), y punto de saturación de la fibra (PSF) se determinaron aplicando las fórmulas específicas de cada componente. La biomasa se estimó con los valores de volumen y densidad básica, además de tres ecuaciones alométricas. Los resultados indican que la DB fue de 0.379 g cm-3, CH de 199.37%, CVT de 13.63%, PSF de 39.28% y promedio de biomasa fustal de 22.79 kg. El ANOVA mostró que la sección dentro del árbol influyó de manera significativa (p < 0.05) en DB y CH, con correlación negativa (r = -0.96). La madera de la plantación es homogénea con respecto a la DB, CH y CVT, mientras que las dos primeras variables presentaron variación radial. La biomasa presentó relación con la densidad básica y el diámetro normal.

Abstract: Commercial forest plantations are a strategy to protect natural forests from overexploitation, so it is important, to know the physical properties of the wood from these plantations. The objective of the work was to determine the quality of the wood based on its physical properties and wood biomass from a Pinus engelmannii plantation of 17 years. The normal diameter and total height were measured in all the trees found in 20 rectangular sites of 3.0 x 6.0 m distributed in four lines. At each site, with a Pressler drill, a growth core was taken at 1.30 m high, in two dominant trees. Physical properties, basic density (DB), moisture content (MC), total volumetric shrinkage (TVC), and fiber saturation point (FSP) were determined by applying the typical formulas. The biomass was estimated with the values of volume and basic density, in addition to three allometric equations. The results were: BD = 0.379 g cm-3, MC = 199.37%, SVT = 13.63%, FSP = 39.28% and an average stem biomass of 22.79 kg. The ANOVA showed that the section within the tree had a significant influence (p < 0.05) on BD and MC, with a high negative correlation (r = -0.96). The plantation wood turned out to be homogeneous with respect to BD, MC, and SVT, while the first two variables showed radial variation. The biomass showed a close relationship with the basic density and the normal diameter.