scholarly journals Distribution of Panama’s narrow-range trees: are there hot-spots?

2021 ◽  
Vol 8 (1) ◽  
Author(s):  
Elizabeth Tokarz ◽  
Richard Condit
Keyword(s):  
Species Richness ◽  
Tree Species ◽  
Large Scale ◽  
Narrow Range ◽  
Hot Spot ◽  
Extinction Risk ◽  
High Elevation ◽  
Total Species Richness ◽  
Range Tree ◽  
Narrow Endemics

Abstract Background Tree species with narrow ranges are a conservation concern because heightened extinction risk accompanies their small populations. Assessing risks for these species is challenging, however, especially in tropical flora where their sparse populations seldom appear in traditional plots and inventories. Here, we utilize instead large scale databases that combine tree records from many sources to test whether the narrow-range tree species of Panama are concentrated at certain elevations or in certain provinces. Past investigations have suggested that the Choco region of eastern Panama and the high mountains of western Panama may be potential hotspots of narrow-range tree species. Methods All individual records were collected from public databases, and the range size of each tree species found in Panama was estimated as a polygon enclosing all its locations. Species with ranges <20,000 km2 were defined as narrow endemics. We divided Panama into geographic regions and elevation zones and counted the number of individual records and the species richness in each, separating narrow-range species from all other species. Results The proportion of narrow endemics peaked at elevations above 2000 m, reaching 17.2% of the species recorded. At elevation <1500 m across the country, the proportion was 6-11%, except in the dry Pacific region, where it was 1.5%. Wet forests of the Caribbean coast had 8.4% narrow-range species, slightly higher than other regions. The total number of narrow endemics, however, peaked at mid-elevation, not high elevation, because total species richness was highest at mid-elevation. Conclusions High elevation forests of west Panama had higher proportions of narrow endemic trees than low-elevation regions, supporting their hot-spot status, while dry lowland forests had the lowest proportion. This supports the notion that montane forests of Central America should be a conservation focus. However, given generally higher diversity at low- to mid-elevation, lowlands are also important habitats for narrow-range tree species, though conservation efforts here may not protect narrow-range tree species as efficiently.

scholarly journals Distribution of Panama’s narrow-range trees: are there hot-spots?

2021 ◽  
Author(s):  
Elizabeth Tokarz ◽  
Richard Condit
Keyword(s):  
Species Richness ◽  
Tree Species ◽  
Rare Species ◽  
Large Scale ◽  
Narrow Range ◽  
Extinction Risk ◽  
High Elevation ◽  
Total Species Richness ◽  
Range Tree ◽  
Many Sources

AbstractBackgroundTree species with narrow ranges are a conservation concern because heightened extinction risk accompanies their small populations. Assessing risks for these species is challenging, however, especially in tropical flora where their sparse populations seldom appear in traditional plots and inventories. Here, we utilize instead large scale databases that combine tree records from many sources to test hypotheses about where the narrow-range tree species of Panama are concentrated.MethodsAll individual records were collected from public databases, and the range size of each tree species found in Panama was estimated as a polygon around all its locations. Rare species were defined as those with ranges < 20,000 km2. We divided Panama into geographic regions and elevation zones and counted the number of individual records and the species richness in each, separating rare species from all other species.ResultsThe proportion of rare species peaked at elevations above 2000 m, reaching 17.3% of the species recorded. At lower elevation across the country, the proportion was 6-11%, except in the dry Pacific region, where it was 1.5%. Wet forests of the Caribbean coast had 8.4% rare species, slightly higher than other regions. The total number of rare species, however, peaked at mid-elevation, not high elevation, because total species richness was highest there.ConclusionsHigh elevation forests of west Panama have higher endemicity of trees than all low-elevation regions. Dry forests had the lowest endemicity. This supports the notion that montane forests of Central America should be a conservation focus, however, given generally higher diversity at low- to mid-elevation, lowlands are also important habitats for rare species.

scholarly journals Estimating the global conservation status of more than 15,000 Amazonian tree species

2015 ◽  
Vol 1 (10) ◽  
pp. e1500936 ◽  
Author(s):  
Hans ter Steege ◽  
Nigel C. A. Pitman ◽  
Timothy J. Killeen ◽  
William F. Laurance ◽  
Carlos A. Peres ◽  
...  
Keyword(s):  
Protected Areas ◽  
Tree Species ◽  
Large Scale ◽  
Gap Analysis ◽  
Extinction Risk ◽  
Conservation Status ◽  
Iucn Red List ◽  
Distribution Models ◽  
Threatened Plant Species ◽  
The Tropics

Estimates of extinction risk for Amazonian plant and animal species are rare and not often incorporated into land-use policy and conservation planning. We overlay spatial distribution models with historical and projected deforestation to show that at least 36% and up to 57% of all Amazonian tree species are likely to qualify as globally threatened under International Union for Conservation of Nature (IUCN) Red List criteria. If confirmed, these results would increase the number of threatened plant species on Earth by 22%. We show that the trends observed in Amazonia apply to trees throughout the tropics, and we predict that most of the world’s >40,000 tropical tree species now qualify as globally threatened. A gap analysis suggests that existing Amazonian protected areas and indigenous territories will protect viable populations of most threatened species if these areas suffer no further degradation, highlighting the key roles that protected areas, indigenous peoples, and improved governance can play in preventing large-scale extinctions in the tropics in this century.

scholarly journals Carbon Sequestration in Relation to Topographic Aspects and Land Use in Northeast of Thailand

2018 ◽  
pp. 118-137 ◽  
Author(s):  
Kazi Kaimul Islam ◽  
Somchai Anusontpornperm ◽  
Irb Kheoruenromne ◽  
Suphicha Thanachit
Keyword(s):  
Species Richness ◽  
Climatic Change ◽  
Hot Spot ◽  
Local Level ◽  
Dominant Factor ◽  
Essential Information ◽  
Total Species Richness ◽  
Western Ghats Of India ◽  
Species Abundances ◽  
Hierarchical Structuring

The Distribution of Species Abundances within natural communities – when properly analysed – can provide essential information regarding general aspects of the internal organisation of these communities. In particular, true species richness on the one hand and the intensity of the process of hierarchical structuring of species abundances on the other hand may be estimated independently and, thereby, can provide truly complementary information. In turn, specific issues may thereby be addressed. For example, whether one unique dominant factor or numerous combined factors are involved in the structuring process of a community can be tested contradictorily. Although these methods are not new conceptually, their implementation in common practice remains scarce. The reason is that the relevant implementation of these methods requires to be sure that virtually all member-species in the community have been sampled. As exhaustive samplings often reveal difficult to achieve in practice, an appropriate, least-biased procedure of numerical extrapolation of incomplete inventories is imperatively required. Considering the steadily increasing threats to the environment and biodiversity, especially facing the on-going climatic change, time has come now with ever greater urgency to go beyond the apparent limits of non-exhaustive sampling and make the most of what is available in terms of recorded field data, whatever the degree of incompleteness of species inventories. As a modest and limited attempt to concretise this wish at the local level, I try, hereafter, to highlight the importance of additional information that may be unveiled  through adequate post-analysis of a set of eight frog communities, recently inventoried by Katwate, Apte & Raut in an amphibian hot-spot in the north-western Ghats of India. At last, the likely variations of both total species richness and the intensity of hierarchical structuring of species abundance are simulated as an answer to the steadily increasing influence of the ongoing climatic change.

scholarly journals Response to Comment on “Impacts of species richness on productivity in a large-scale subtropical forest experiment”

Science ◽  
2019 ◽  
Vol 363 (6423) ◽  
pp. eaav9863 ◽  
Author(s):  
Helge Bruelheide ◽  
Yuxin Chen ◽  
Yuanyuan Huang ◽  
Keping Ma ◽  
Pascal A. Niklaus ◽  
...  
Keyword(s):  
Species Richness ◽  
Tree Species ◽  
Large Scale ◽  
Subtropical Forest ◽  
Natural Forests ◽  
Tree Species Richness ◽  
Species Pools

Yang et al. have raised criticism that the results reported by us would not be relevant for natural forests. We argue that productivity is positively related to species richness also in subtropical natural forests, and that both the species pools and the range of tree species richness used in our experiment are representative of many natural forests of this biome.

scholarly journals Hydraulic diversity stabilizes productivity in a large-scale subtropical tree biodiversity experiment

2021 ◽  
Author(s):  
Florian Schnabel ◽  
Xiaojuan Liu ◽  
Matthias Kunz ◽  
Kathryn E. Barry ◽  
Franca J. Bongers ◽  
...  
Keyword(s):  
Climate Change ◽  
Species Richness ◽  
Tree Species ◽  
Structural Equation ◽  
Large Scale ◽  
Structural Equation Models ◽  
Forest Productivity ◽  
Climate Mitigation ◽  
Climate Change Effects ◽  
Tree Species Richness

AbstractExtreme climatic events threaten forests and their climate mitigation potential globally. Understanding the drivers promoting ecosystems stability is therefore considered crucial to mitigate adverse climate change effects on forests. Here, we use structural equation models to explain how tree species richness, asynchronous species dynamics and diversity in hydraulic traits affect the stability of forest productivity along an experimentally manipulated biodiversity gradient ranging from 1 to 24 tree species. Tree species richness improved stability by increasing species asynchrony. That is at higher species richness, inter-annual variation in productivity among tree species buffered the community against stress-related productivity declines. This effect was mediated by the diversity of species’ hydraulic traits in relation to drought tolerance and stomatal control, but not the community-weighted means of these traits. Our results demonstrate important mechanisms by which tree species richness stabilizes forest productivity, thus emphasizing the importance of hydraulically diverse, mixed-species forests to adapt to climate change.

Tree species richness modulates water supply in the local tree neighbourhood: evidence from wood δ 13 C signatures in a large-scale forest experiment

2021 ◽  
Vol 288 (1946) ◽  
pp. 20203100
Author(s):  
Kirstin Jansen ◽  
Goddert von Oheimb ◽  
Helge Bruelheide ◽  
Werner Härdtle ◽  
Andreas Fichtner
Keyword(s):  
Species Richness ◽  
Water Supply ◽  
Water Use ◽  
Water Availability ◽  
Tree Species ◽  
Large Scale ◽  
Isotope Composition ◽  
Tree Diversity ◽  
Tree Species Richness ◽  
Neighbourhood Scale

Biodiversity is considered to mitigate the adverse effects of changing precipitation patterns. However, our understanding of how tree diversity at the local neighbourhood scale modulates the water use and leaf physiology of individual trees remains unclear. We made use of a large-scale tree diversity experiment in subtropical China to study eight tree species along an experimentally manipulated gradient of local neighbourhood tree species richness. Twig wood carbon isotope composition ( δ 13 C wood ) was used as an indicator for immediate leaf-level responses to water availability in relation to local neighbourhood conditions and a target tree's functional traits. Across species, a target tree's δ 13 C wood signatures decreased progressively with increasing neighbourhood species richness, with effects being strongest at high neighbourhood shading intensity. Moreover, the δ 13 C wood -shading relationship shifted from positive (thin-leaved species) or neutral (thick-leaved species) in conspecific to negative in heterospecific neighbourhoods, most likely owing to a lower interspecific competition for water and microclimate amelioration. This suggests that promoting tree species richness at the local neighbourhood scale may improve a tree's local water supply with potential effects for an optimized water-use efficiency of tree communities during drought. This assumption, however, requires validation by further studies that focus on mechanisms that regulate the water availability in mixtures.

scholarly journals Do terrestrial protected areas conserve freshwater fish diversity? Results from the Western Ghats of India

Oryx ◽  
2012 ◽  
Vol 46 (4) ◽  
pp. 544-553 ◽  
Author(s):  
Robin Kurian Abraham ◽  
Nachiket Kelkar
Keyword(s):  
Species Richness ◽  
Protected Areas ◽  
Western Ghats ◽  
High Elevation ◽  
Freshwater Ecosystems ◽  
Fish Diversity ◽  
Freshwater Biodiversity ◽  
Total Species Richness ◽  
Dam Reservoirs ◽  
Western Ghats Of India

AbstractTerrestrial protected areas are often designated in inaccessible high elevation regions, and usually targeted towards conservation of charismatic large mammals and birds. It has been suggested that such protected areas, with partial coverage of riverine habitats, may not be adequate for conservation of freshwater taxa such as fishes. Also, protected areas are often designated in upstream catchments of dam reservoirs, and conservation of freshwater biodiversity is usually not a priority. We investigated the importance of existing protected areas for conservation of stream fishes within and across three dammed and two undammed rivers in the southern Western Ghats, India (a global biodiversity hotspot). Comparisons of stream sites in protected and unprotected areas were restricted to mid elevations because of confounding factors of dams, elevation and stream order. For dammed rivers, endemic and total species richness was significantly higher inside protected areas than unprotected areas. Total fish species richness increased with decreasing elevation and endemic species richness peaked at mid elevations. Species found in comparable stream orders across dammed and undammed midland river reaches were similar. Intensity of threats such as sand mining, dynamite fishing, pollution and introduced invasive fishes was higher in unprotected than in protected areas. Lack of awareness among managers has also led to the occurrence of some threats within protected areas. However, existing protected areas are vital for conservation of endemic fishes. Our results support the need for extending the scope of terrestrial protected areas towards better representation of freshwater ecosystems and biodiversity.

Comment on “Impacts of species richness on productivity in a large-scale subtropical forest experiment”

Science ◽  
2019 ◽  
Vol 363 (6423) ◽  
pp. eaav9117
Author(s):  
Hua Yang ◽  
Zhongling Guo ◽  
Xiuli Chu ◽  
Rongzhou Man ◽  
Jiaxin Chen ◽  
...  
Keyword(s):  
Species Richness ◽  
Tree Species ◽  
Large Scale ◽  
Forest Productivity ◽  
Subtropical Forest ◽  
Species Loss ◽  
Subtropical China

Huang et al. (Reports, 5 October 2018, p. 80) report significant increases in forest productivity from monocultures to multispecies mixtures in subtropical China. However, their estimated productivity decrease due to a 10% tree species loss seems high. We propose that including species richness distribution of the study forests would provide more meaningful estimates of forest-scale responses.

scholarly journals Temporal and Spatial Use of Even-Aged Reproduction Stands by Bird Communities in Central Pennsylvania

2003 ◽  
Vol 20 (3) ◽  
pp. 117-123 ◽  
Author(s):  
Susan C. Talbott ◽  
Richard H. Yahner
Keyword(s):  
Species Richness ◽  
Breeding Season ◽  
Tree Species ◽  
Management Practice ◽  
Bird Species ◽  
Basal Area ◽  
Total Species Richness ◽  
Species Richness And Abundance ◽  
Overstory Trees ◽  
Total Species

Abstract In 1992, the Pennsylvania Bureau of Forestry adopted a new forest management practice known as even-aged reproduction with reservation (EAR), which replaces clearcutting on state forestlands. The EAR guidelines mandate the retention of at least 12 trees/ha and 24–36 m2/ha of basal area, representing a diversity of overstory and understory species. During summer 1998, we compared the temporal (breeding season vs. mid-summer) and spatial (edge versus interior) use of EAR stands by birds. In addition, we compared observed vs. expected use of overstory trees in EAR stands. In each of ten representative EAR stands, we sampled birds twice per season along two-edge and two-interior transects. Total species richness and abundance (all species combined), species richness and abundance of ground-shrub foragers, and species richness of canopy-sallier foragers were significantly (P < 0.05) higher in the breeding season than in mid-summer. Eight of 20 common bird species analyzed also were significantly (P < 0.05) more abundant during the breeding season (e.g., black-and-white warbler and chestnut-sided warbler), and one species was significantly (P < 0.05) more abundant during mid-summer. Total species richness, total abundance, and abundance of ground-shrub foragers were significantly higher (P < 0.05) in interiors compared to edges of EAR stands. Five species also were significantly (P < 0.05) more abundant in interiors of EAR stands, whereas no species was more common in edges. All species combined and three foraging guilds showed differential use (P < 0.05) of overstory tree species; eight species also differed significantly in their use of abundant tree species. Based on our findings, we believe that EAR stands are excellent substitutes for clearcuts on state forestlands, although we caution that our findings were based only on one yr of data. We recommend the continued retention of a diversity of overstory trees, especially snags and rough-barked trees, in both edges and interiors of EAR stands for use by a variety of bird species during both the breeding season and mid-summer. North. J. Appl. For. 20(3):117–123.

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