Native forest replacement by exotic plantations in southern Chile (1985–2011) and partial compensation by natural regeneration

Abstract Since its first introduction in the 19th century, Douglas-fir has become the economically most important non-native forest tree species in Central European countries. Many of these planted forests are important seed sources and/or exhibit natural regeneration. Thus, it is important to assess (1) the genetic diversity of the mature stands and (2) if the genetic diversity can be passed on to the next generations. In order to address these issues, we genotyped mature Douglas-fir individuals and natural regeneration from >100 native and non-native populations using nuclear microsatellite markers. We compared the genetic diversity of native North American populations with mature Douglas-fir populations in Central Europe. The results show that genetic diversity did not differ significantly between European populations and the assigned native origin. Using a subset of 36 sites from Central Europe, we detected a significant reduction in the genetic diversity of adult versus naturally regenerated juvenile trees, indicating a bottleneck effect in the next generation of European Douglas-fir stands. The main reason may be that the mature European Douglas-fir stands are highly fragmented and thus the stand size is not adequate for transmitting the genetic diversity to the next generation. This should be taken into account for the commercial harvesting of seed stands. Seed orchards may offer a potential alternative in providing high quality and genetically diverse reproductive material.

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Diversity of Diurnal Raptors in a Suburban Area of a City in Southern Chile

10.21203/rs.3.rs-500326/v1 ◽

2021 ◽

Author(s):

Andrés Muñoz-Pedreros ◽

Varia Dellacasa

Keyword(s):

Spatial Location ◽

Suburban Area ◽

Tree Plantations ◽

Native Forest ◽

Southern Chile ◽

Territorial Planning ◽

Exotic Tree ◽

Acoustic Surveys ◽

Raptor Conservation ◽

The Relationship

Abstract Raptor conservation programs should be based on knowledge of the birds’ ecology in both natural and urban habitats, justifying the inclusion of ecological studies in suburban zones into regional planning initiatives. The objectives of this study were (a) to determine the use by diurnal raptors of the habitat in a suburban area of a city in southern Chile, and (b) to characterize the different zones into five types of environment, and assess their raptor diversity for consideration in territorial planning. Acoustic surveys were conducted in auditory stations in addition to observations from fixed transects and trails. From a total of 161.39 hours of census, we obtained 664 sightings corresponding to ten species of diurnal raptors. The richest environment was dense forest (eight species), followed by grassland (six species), native forest regeneration (five species), shrubs (four species) and exotic tree plantations (three species). We discuss the relationship between the richness of diurnal raptors, the types of environment in the study area, and the spatial location of the sites, as well as the implications for territorial planning to support the conservation of birds of prey in the suburban zone studied.

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Trade-offs between environmental and economic factors in conversion from exotic pine production to natural regeneration on erosion prone land

New Zealand Journal of Forestry Science ◽

10.33494/nzjfs512021x163x ◽

2021 ◽

Vol 51 ◽

Author(s):

Suzanne Lambie ◽

Shaun Awatere ◽

Adam Daigneault ◽

Miko Kirschbaum ◽

Michael Marden ◽

...

Keyword(s):

Natural Regeneration ◽

Forest Cover ◽

Regional Scale ◽

Cost Benefit ◽

Native Forest ◽

Limited Information ◽

Honey Production ◽

Trade Offs ◽

Erosion Mitigation ◽

Very High

Background: Some of New Zealand’s exotic pine (Pinus radiata D.Don) forests were planted for erosion mitigation but cultural, legislative, environmental, and profitability limitations in some parts of the landscape have led to reassessment of their suitability. There is limited information to support landowner decisions on the viability of natural regeneration of native forest post-pine-harvest. Methods: We evaluated scenarios of post-harvest natural regeneration, compared to remaining in pine production, using erosion susceptibility determined from historical occurrence of landslides, gullies and earthflows, biophysical growth modelling of mānuka–kānuka (Leptospermum scoparium-Kunzea ericoides (A.Rich) Joy Thomps.) shrubland using the process-based CenW model, and cost-benefit analyses using NZFARM with two land use change scenarios, at two levels of erosion mitigation ± honey profits. Results: In our study area, the Gisborne Region (North Island of New Zealand), ~27% of the land has moderate–very high susceptibility to landslides, 14–22% a high probability of contributing material to waterways, and 19% moderate–very high gully erosion susceptibility. Pines grow 10 times faster than naturally regenerating mānuka–kānuka shrubland, but mānuka–kānuka is used for honey not wood production. Natural regeneration resulted in losses of $150–250 ha-1 yr-1 compared to the current profitability of pine production. Honey production offset some reduction in pine revenue, but not fully. Thus, the viability of shifting from pines to native forest is highly dependent on landowner impetus and value for non-market ecosystem services (such as cultural and biodiversity values) provided by native forest. Conclusions: A mosaic of land uses within a property may sufficiently offset income losses with other benefits, whereby highly erosion-prone land is shifted from rotational pine forest production to permanent native forest cover with honey production where possible. At the regional scale in Gisborne, the conversion of the most highly susceptible land under production forestry (315–556 ha) to natural regeneration has the potential for wider benefits for soil conservation reducing erosion by 1–2.5 t yr–1 of sediment facilitating achievement of cleaner water aspirations and habitat provision.

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THE NEED TO STUDY SILVICULTURAL EFFECTS OF MECHANIZED LOGGING SYSTEMS IN EASTERN CANADA

The Forestry Chronicle ◽

10.5558/tfc41252-2 ◽

1965 ◽

Vol 41 (2) ◽

pp. 252-256 ◽

Cited By ~ 2

Author(s):

G. F. Weetman

Keyword(s):

Nutrient Cycling ◽

Natural Regeneration ◽

Native Forest ◽

Forest Stands ◽

Eastern Canada ◽

Tree Crowns

Biological problems which may result from the use of heavy logging equipment are discussed. Scarification from logging rarely produces enough seedbed favourable to natural regeneration. Full-tree logging may cause nutrition problems by removing tree crowns from poor sites. Well designed studies of various kinds of logging systems are needed to assess their effects on the stand, soil and future regeneration. Studies of nutrient cycling in native forest stands might indicate some of the effects of full tree logging.

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Root-Associated Fungal Communities in Two Populations of the Fully Mycoheterotrophic Plant Arachnitis uniflora Phil. (Corsiaceae) in Southern Chile

Microorganisms ◽

10.3390/microorganisms7120586 ◽

2019 ◽

Vol 7 (12) ◽

pp. 586 ◽

Cited By ~ 1

Author(s):

Hector Herrera ◽

Javiera Soto ◽

Luz E. de Bashan ◽

Inmaculada Sampedro ◽

Cesar Arriagada

Keyword(s):

Endophytic Fungi ◽

Sampling Site ◽

Mixed Forest ◽

Native Forest ◽

Southern Chile ◽

Cupressus Sempervirens ◽

Acetic Acid Production ◽

Fungal Strains ◽

Stimulate Plant Growth ◽

Organic Acid Exudation

The microbiological interactions of the roots of non-photosynthetic plants in South America have been scarcely explored. This study analyzes culturable fungal diversity associated with the mycoheterotrophic plant Arachnitis uniflora Phil. (Corsiaceae) in southern Chile, growing in two different understoreys of native (Nothofagus-dominated) and mixed forest (native, Cupressus sempervirens, and Pinus radiata). Rhizospheric and endophytic fungi were isolated, cultured, and purified to identify microorganisms associated with A. uniflora roots. We showed the different fungi associated with the plant, and that these distributions are influenced by the sampling site. We isolated 410 fungal strains (144 endophytic and 266 from the rhizosphere). We identified 13 operative taxonomical units from plants sampled in the mixed forest, while 15 were from the native forest. Rhizospheric microorganisms were mainly related to Penicillium spp., whereas some pathogenic and saprophytic strains were more frequent inside the roots. Our results have also shown that the fungal strains are weak for phosphate solubilization, but other pathways such as organic acid exudation and indole acetic acid production can be considered as major mechanisms to stimulate plant growth. Our results point to new fungal associates of A. uniflora plants reported in Andean ecosystems, identifying new beneficial endophytic fungi associated with roots of this fully mycoheterotrophic plant.

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Soil type modulates the response of C, N, P stocks and stoichiometry after native forest substitution by exotic plantations

CATENA ◽

10.1016/j.catena.2020.104997 ◽

2021 ◽

Vol 197 ◽

pp. 104997

Author(s):

Oscar Crovo ◽

Felipe Aburto ◽

María Fernanda Albornoz ◽

Randal Southard

Keyword(s):

Soil Type ◽

Native Forest ◽

Exotic Plantations

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Advance of Urochloa decumbens (Stapf) R.D. Webster (Poaceae) on remaining native forest in the Serra da BODOQUENA NATIONAL PARK

Biodiversidade Brasileira - BioBrasil ◽

10.37002/biobrasil.v10i2.1481 ◽

2020 ◽

pp. 148-157

Author(s):

José Guilherme Dias De Oliveira ◽

Luiz Fernando Duarte De Moraes ◽

Tânia Sampaio Pereira ◽

Geraldo Alves Damasceno Junior

Keyword(s):

Natural Regeneration ◽

National Park ◽

Invasive Alien Species ◽

Habitat Destruction ◽

Native Forest ◽

Natural Forests ◽

Fire Control ◽

Exotic Grasses ◽

Forest Remnants ◽

Urochloa Decumbens

The replacement of native forest by exotic grasses for pasture formation is a process that involves habitat destruction followed by the introduction of invasive alien species. The Serra da Bodoquena National Park covers an area of 77,021.58ha, comprising natural forests and remnants of abandoned pastures, which represent a threat to local biodiversity conservation. This study analyzed the dynamics of Urochloa decumbens–dominated matrix on remnants of native Deciduous Seasonal Forest within the Park, over 35 years, using satellite images, evaluating natural regeneration trend. The Urochloa matrix covers 1,268.9 (36.9%) of the 3,434.50 hectares study area. Our results indicate that the Urochloa matrix expanded over the native forest remnants, likely due to the occurrence of fire close to the forest edges, which may help natural regeneration failing. 8 months after a fire in 2013, the area of the grass-dominates matrix was found to replace 203.1 hectares over the forest. In this context, restoration actions are demanded, especially those that target fire control.

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Distribution modelling of the Pudu deer (Pudu puda) in southern Chile

Nature Conservation ◽

10.3897/natureconservation.41.53748 ◽

2020 ◽

Vol 41 ◽

pp. 47-69

Author(s):

Nelson Colihueque ◽

Aldo Arriagada ◽

Andrea Fuentes

Keyword(s):

Native Forest ◽

Mountain Range ◽

Southern Chile ◽

Distribution Modelling ◽

Conservation Implications ◽

The Andes ◽

Modelling Method ◽

Extensive Coverage ◽

Maxent Modelling ◽

Coastal Mountain

The Pudu deer (Pudu puda) is endemic to the temperate rainforest of Chile and Argentina and currently faces serious conservation problems related to habitat loss. However, studies undertaken on this species are not sufficient to identify suitable areas for conservation purposes across its distribution range. In order to estimate the current and future distribution of the Pudu deer in southern Chile, we modelled the potential distribution of this species, based on occurrence points taken from seven contiguous provinces of this area using the Maxent modelling method. The Pudu deer distribution covered an estimated area of 17,912 km2 (24.1% of the area analysed), using a probability of occurrence above 0.529, according to the threshold that maximises the sum of sensitivity and specificity. In contrast to the Andes mountain range, areas with higher probabilities of occurrence were distributed mainly on the eastern and western slopes of the Coastal Mountain Range, where extensive coverage of native forest persists, as occurs in the provinces of Ranco, Osorno and Llanquihue. Projections to 2070, with global warming scenarios of 2.6 and 8.5 rcp, revealed that large areas will conserve their habitability, especially in the Coastal mountain range. Our results reveal that the Coastal mountain range has a high current and future habitability condition for the Pudu deer, a fact which may have conservation implications for this species.

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A cost effective stratified two-stage sampling design to estimate the forest land area of southern Chile

Canadian Journal of Forest Research ◽

10.1139/x11-040 ◽

2011 ◽

Vol 41 (7) ◽

pp. 1509-1521

Author(s):

Mario E. Niklitschek ◽

Guillermo Trincado

Keyword(s):

Mean Square Error ◽

Optimal Allocation ◽

Native Forest ◽

Ratio Estimator ◽

Mean Square ◽

Forest Plantation ◽

Southern Chile ◽

Unified Framework ◽

Two Stage ◽

Ratio Estimators

There is a growing demand for improving the measurement of forest resources, with more frequent updating and better information on environmental variables. We explore the cost efficiency of a stratified two-stage design using area sampling to estimate the forest plantation and native forest areas in southern Chile. Analytical expressions for the approximate mean square error of combined and separate ratio estimators are derived applying Taylor linearization. Under a unified framework, this procedure allows the evaluation of the precision of design and post-design estimators for unequal unit area sizes at both stages. Monte Carlo simulations were used to assess empirically the approximate analytical measures of the mean square error and the biases associated with the ratio estimators. Adopting proportional allocation among strata and clusters, the optimal allocation among the two stages is determined. A substantial improvement in sampling precision was achieved using the separate ratio estimator and the bias was found to be small. Post-stratification based on categorical information on growing zones also improved the precision of estimating the forest plantation area and a smaller extent the native forest area. The results of this paper support a wider adoption of sampling methods to estimate land use and land cover at regional or national levels.

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