Comparison of four different programs for the analysis of hemispherical photographs using parameters of canopy structure and solar radiation transmittance

There have been many studies involving the use of hemispherical photographs to indirectly estimate canopy structures and forest light environments. A variety of commercial and free software packages are available for the analysis of hemispherical photographs. The costs of investment might represent an advantage of the free programmes over the commercial, but as yet little has been documented about the differences in their outputs and in the technical applications from a user (ecologist and forester) perspective. The objective of the study was to compare the canopy structure variables (canopy openness and effective plant area index) and solar radiation transmission estimates (direct, diffuse and global solar radiation transmittances) from digital hemispherical photographs taken under two forest canopy conditions (gap and closed canopy) in three different broadleaf forest regions (Chile, Germany, Venezuela) and calculated using four different programmes. The hemispherical photographs were analysed using one commercial (HemiView) and three free programmes (Gap Light Analyzer, hemIMAGE and Winphot). The results obtained revealed that all of the programmes computed similar estimates of both canopy structures and below-canopy solar radiation. Only the results relating to the effective plant area index with an ellipsoidal leaf angle distribution made with HemiView and Winphot deviated significantly. Other user aspects are also discussed, such as costs, image formats, computer system requirements, etc.In vielen Studien werden Hemisphärenphotos genutzt um indirekt die Kronenstruktur und die Belichtungsverhältnisse zu schätzen. Verschiedene kommerzielle und kostenfreie Softwarepakete sind zu Analyse von Hemisphärenphotos verfügbar. Es gibt bisher keine umfassende Vergleichsstudie zu Ergebnissen oder technischer Handhabung aus Sicht der Nutzer dieser Programme (Ökologen und Forstwissenschaftler). Das Ziel dieser Studie war der Vergleich der Schätzungen von Kronenstrukturvariablen (Kronenöffnung und effektiver Pflanzenflächenindex) Solartransmission (direkte, diffuse und Global-Strahlung) aus digitalen Hemisphärenphotos berechnet mit vier verschiedenen Programmen (kostenpflichtig: Hemi- View und frei: Gap Light Analyzer, hemIMAGE and Winphot). Die verwendeten Photos stammen aus drei verschiedenen Laubwaldregionen (Chile, Deutschland und Venezuela) und repräsentieren jeweils Verhältnisse unter geschlossenem Kronendach und in Lücken. Die ermittelten Schätzungen für die verschiedenen Strukturvariablen und Einstrahlungsverhältnisse zeigten eine sehr hohe Übereinstimmung. Einzig der effektive Pflanzenflächenindex basierend auf ellipsoider Blattwinkelverteilung unterschied sich signifikant zwischen den Programmen. Weitere für Nutzer interessante Aspekte wie Kosten, Bildformate, Systemvoraussetzungen und mehr wurden verglichen und diskutiert

Canopy composition and site are indicative of mineral soil conditions in Patagonian mixed Nothofagus forests

Key message: Canopy composition in mixed Patagonian Nothofagus forests has an impact on soil properties like cationic exchange capacity and pH, while most soil variables changed with site [P, cation exchange capacity (CEC), soil moisture (SM), resistance to penetration (R)]. Site conditions and canopy composition need be considered together to better understand the distribution of Nothofagus species.Context: Forests can influence soil development, changing main soil properties by several mechanisms, but this has never been investigated in mixed Nothofagus forests. Such influences can be strongly variable depending on local site conditions, and the interactions between both factors need to be clearly established.Aims: To reveal the effect on physical and chemical mineral soil properties in mixed Nothofagus forests of canopy composition and their interactions with site conditions.Methods: Two sites and threemixed forest types, with different proportion of deciduous-evergreen,were selected in coastal andmountain sites. We evaluated forest structure, litterfall and physico-chemical properties of mineral soil (N= 60), and analyzed these factors with general linear models and multivariate statistics [multi-response permutation procedure (MRPP), principal component analyses (PCA)].Results: Basal area and litterfall were significantly influenced by forest type × sites. CEC and pH value varied among forests types and sites, but sites also influenced other variables (P, SM, R). Multivariate analyses reveals a much stronger effect of site conditions than that of species mixture.Conclusion: Forest soil studies must consider environmental factors on different spatial scale and canopy species composition to better understand their influence on soil dynamics in mixed Nothofagus forests.Fil: Toro Manríquez, Mónica del Rosario. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Austral de Investigaciones Científicas; ArgentinaFil: Soler Esteban, Rosina Matilde. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Austral de Investigaciones Científicas; ArgentinaFil: Lencinas, María Vanessa. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Austral de Investigaciones Científicas; ArgentinaFil: Promis, Álvaro. Universidad de Chile; Chil

Respuesta temprana de la regeneración de plantas leñosas después del incendio forestal denominado “Las Máquinas” en la Región del Maule, Chile

The post-fire woody plant species regeneration was assessed in a Nothofagus glauca dominated forest and a clearcutting of Pinus radiata. Native species showed a high vegetative regeneration capacity after wildfire.However, an invasion of seedlings of Pinus radiata is occurring, especially in the N. glauca forest. &nbsp

Análisis de los micrositios de regeneración para Nothofagus pumilio en sectores perturbados y no perturbados por el efecto del Castor canadensis en Tierra del Fuego, Chile

Castor canadensis afecta a bosques de Nothofagus en Tierra del Fuego, por construcción de castoreras e inundación de bosques. Luego de la eliminación de castores, el sector inundado cambia a una pradera abierta. El objetivo es analizar el establecimiento de plantas de regeneración de N. pumilio (lenga) respecto a micrositios en pradera de castor y bosque no afectado por castor. La investigación se desarrolló en una castorera abandonada, en el sector de Vicuña, Tierra del Fuego (54º8?S, 68º42?O). En la vecindad de la castorera se encuentra un bosque de lenga coetáneo (390 árboles/ha, 93,5 m2/ha). En la pradera de castor y en el bosque se instalaron sistemáticamente 121 y 88 parcelas para estimación de cobertura de cada uno de los sustratos presentes. En las parcelas se identificaron los micrositios que están siendo utilizados por las plantas de regeneración de lenga. Las plantas fueron caracterizadas y se identificó la presencia de ramoneo por Lama guanicoe (guanaco). Los resultados establecen que los principales sustratos en la pradera corresponden a conjuntos de plantas herbáceas (47,9% de cobertura) y madera en descomposición grado 1 (12,6%). En el bosque el sustrato del suelo está cubierto mayoritariamente por plantas herbáceas (30,7%) y hojarasca (13,7%). En la pradera se encontraron 1,9 plantas de regeneración por m2, estableciéndose mayoritariamente sobre plantas herbáceas (entre 52,2 y 55,6% de las plantas). En el bosque de lenga se encontraron 10,0 plantas de regeneración por m2, las que se encontraban creciendo mayoritariamente sobre madera en descomposición grado 3 (39,7 a 44,6%). El 81,5% de las plantas se encuentran ramoneadas por guanaco en la pradera de castor y solamente el 15,9% en el bosque. Actividades de restauración de castoreras abandonadas deberían considerar el establecimiento de plantas de regeneración en micrositios que son utilizados naturalmente por lenga, además de aislar la presencia de guanaco.Fil: Toro Manríquez, Mónica del Rosario. Universidad de Chile; Chile. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Austral de Investigaciones Científicas; ArgentinaFil: Promis Baeza, Alvaro Andres. Universidad de Chile; ChileVI Congreso Chileno de Ciencias ForestalesTemucoChileUniversidad de La FronteraSociedad Chilena de Ciencias Forestale

Rehabilitation of Nothofagus pumilio forests in Chilean Patagonia: can fencing and planting season effectively protect against exotic European hare browsing?

In forests affected by heavy fires and continuous grazing of exotic herbivorous mammal species, Nothofagus pumilio (lenga) cannot recover naturally. The main factors that hinder the natural recovery of these forests and the feasibility of native tree plantations are the exotic herbivorous pressure, like that produced by Lepus europaeus (European hare), and the environment degradation degree by anthropic disturbances. The objective of this study was to evaluate different plantation efforts to recover N. pumilio forests degraded by fires in Chilean Patagonia. The plantation actions also included wire fences for sapling protection in 100 ha, where 60 ha were established during autumn (May 2012), and 40 ha were established during spring (October 2012). In March 2013 we recorded the height annual growth (cm year−1), the section browsed at each sapling, the modification of plant form (number of new branches), and the vigor expression. We evaluated the data using one- and two-way ANOVAs, Cohen's d effect size, and chi-square analyses. We measured a total of 872 plants, where 42% presented damages caused by European hare browsing. These results indicated that the wire fences were not completely useful to stop the damage on saplings (Cohen's d effect size= <0.2). We also found that autumn plantations were more susceptible to damage than those established during spring. European hares predominantly browsed on a particular sapling section: the apical buds. As a consequence, the browsed saplings had lower height growth than undamaged ones. These outputs highlight the need to explore and implement alternative actions for the rehabilitation of these degraded deciduous forests, to achieve the objectives of sustainable management or to recover the natural ecosystem functions.Fil: Huertas Herrera, Alejandro. Ulterarius Consultores Ambientales y Científicos Ltda; Chile. Universidad de Magallanes; Chile. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Promis Baeza, Alvaro Andres. Universidad de Chile; ChileFil: Toro Manríquez, Mónica del Rosario. Universidad de Magallanes; Chile. Ulterarius Consultores Ambientales y Científicos Ltda; Chile. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Lencinas, María Vanessa. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Austral de Investigaciones Científicas; ArgentinaFil: Martínez Pastur, Guillermo José. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Austral de Investigaciones Científicas; ArgentinaFil: Río, Matias. Fundación Reforestemos Patagonia; Chil

Descripción de la flora vascular en el sotobosque de un bosque pantanoso y de una pradera antropogénica húmeda de Juncus procerus en el valle del río Cisnes, Región de Aysén, Chile

The richness, abundance and density of vascular flora species were evaluated in the understory of a swamp forest (BP) dominated by Luma apiculata and in an anthropogenic Juncus procerus wet praire (PHJ). The most diverse taxonomical groups were fern in BP and dycotiledon in PHJ. Introduced species were only found in PHJ. Epiphytic hemicryptophytes and climbing phanerophytes are indicator species for BP and hemicryptophyes for PHJ

Inferring population dynamic trends of Nothofagus pumilio and N. betuloides in coastal and mountain forests of Tierra del Fuego: contrasting from flowering to seedling survival through several reproductive cycles

Transition from fower to seedling encompasses major processes that defne the success of the tree regeneration, and consequently, its study is crucial in the context of forest management. Here, we analysed the transition probability of the reproductive cycle of two Nothofagus species, which formed pure and mixed forests in coastal and mountain geographic locations of Tierra del Fuego (Argentina). Pure deciduous N. pumilio (Np), pure evergreen N. betuloides (Nb), and mixed N. pumilio–N. betuloides (M) forests in coasts and mountains (3 forest types×2 geographic locations×20 replicas=120 replicas) were evaluated. Reproductive structures (female fowers, fruits, seeds, sound seeds, emerged seedlings and surviving seedlings up to 2 years) were studied since 2012–2018. Our results suggested that transition probabilities from fower to surviving seedlings varied inter-annually between N. pumilio and N. betuloides. The hazard ratio in the transition showed an infuence of the cohorts and the geographic location on N. pumilio, while forest type and geographic location infuenced on N. betuloides. Flower to fruits and seed to seedling were the most critical process in all forest types and locations. Cumulative transition probabilities (female fowers to 2-year-old seedlings) for N. pumilio were 0.3–46.2% in Np and 1.4–30.2% in M, and pure and mixed forests reached similar probabilities only in cohort 3. For N. betuloides, these were 2.8–24.4% in Nb and 0.0–6.5% in M. Both Nothofagus species showed a better performance of pure forests in mountains (15.9–46.2% Np; 3.8–24.8% Nb) than in coasts (0.3–16.1% Np; 2.8–5.3% Nb). Through this integrated approach, considering the full reproductive cycle, it is possible to quantify the infuence of canopy composition and inter-annual variability in natural forest dynamic, and allows to identify the critical stages of tree recruitment in pure and mixed Nothofagus forests.Fil: Toro Manríquez, Mónica del Rosario. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Austral de Investigaciones Científicas; Argentina. Universidad de Magallanes; Chile. Ulterarius Consultores Ambientales y Científicos Ltda; ChileFil: Soler Esteban, Rosina Matilde. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Austral de Investigaciones Científicas; ArgentinaFil: Huertas Herrera, Alejandro. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Austral de Investigaciones Científicas; Argentina. Ulterarius Consultores Ambientales y Científicos Ltda; Chile. Universidad de Magallanes; ChileFil: Lencinas, María Vanessa. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Austral de Investigaciones Científicas; ArgentinaFil: Promis, Álvaro. Universidad de Chile; ChileFil: Blazina, Ana Paula. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Austral de Investigaciones Científicas; ArgentinaFil: Martínez Pastur, Guillermo José. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Austral de Investigaciones Científicas; Argentin

Forest canopy-cover composition and landscape influence on bryophyte communities in Nothofagus forests of southern Patagonia

Bryophytes (liverworts, mosses and hornworts) are one of the most diverse plant groups worldwide but one of the least studied in temperate forests from an ecological perspective. In comparison to vascular plants, bryophytes have a broader distribution and a longer altitudinal gradient, and their influence on the landscape is poorly understood. The objective was to evaluate environmental drivers that can influence bryophyte cover, richness, diversity, and nestedness in different forest canopy compositions in two typical landscapes across the natural distribution of bryophytes in Tierra del Fuego (Argentina). Three natural Nothofagus forest types (pure deciduous, pure evergreen, and mixed deciduous-evergreen) in two landscapes (coasts 400 m.a.s.l.) were selected (N = 60 plots). In each plot, we established one transect (10 m length) to measure bryophyte cover (pointintercept method). Data were evaluated using generalized linear mixed models and multivariate analyses. The studied environmental drivers were mainly explained by the microclimate, with higher effective annual precipitation and relative air humidity in the coastal forests and higher soil moisture in the mountain forests. Greater liverwort richness was found in evergreen forests at the mountain (9 species) than at the coastal, while mosses showed higher richness in mixed deciduous-evergreen forests at the coastal (11 species) than at the mountain. However, the expected richness according to the rarefaction/extrapolation curves suggested that it is possible to record additional species, except for liverworts in pure deciduous forests on the coasts. Similarities and differences among the studied forest types and among plots of the same forest type and landscape were detected. These differences in the studied indexes (similarity that varied between 0 and 1) ranged from 0.09- 0.48 for liverworts and 0.05-0.65 for mosses. Moreover, these results indicated that pure evergreen and mixed deciduous-evergreen forests presented higher moss cover (10.7% and 10.0%, respectively), mainly in the mountains than on the coast. These outputs highlight the need to explore differences at greater altitudinal ranges to achieve sustainability objectives conservation planning for bryophytes in southernmost forests.Fil: Toro Manríquez, Mónica del Rosario. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Austral de Investigaciones Científicas; ArgentinaFil: Ardiles, Víctor. Museo Nacional de Historia Natural de Santiago; ChileFil: Promis, Álvaro. Universidad de Chile; ChileFil: Huertas Herrera, Alejandro. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Austral de Investigaciones Científicas; ArgentinaFil: Soler Esteban, Rosina Matilde. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Austral de Investigaciones Científicas; ArgentinaFil: Lencinas, María Vanessa. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Austral de Investigaciones Científicas; ArgentinaFil: Martínez Pastur, Guillermo José. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Austral de Investigaciones Científicas; Argentin