scholarly journals Probing the troublesome peaked relationship between avian species richness and natural land cover

2021 ◽  
Author(s):  
Rafael Xavier De Camargo ◽  
David Currie
Keyword(s):  
Species Richness ◽  
Land Cover ◽  
Landscape Heterogeneity ◽  
New York State ◽  
Pool Size ◽  
Avian Species ◽  
Temperature Gradients ◽  
Species Pool ◽  
Natural Land ◽  
The Relationship

Abstract Context : Biodiversity models postulate that the relationship between richness and the proportion of natural land cover (pNLC i.e., not dominated by human uses) is: 1) monotonic positive, 2) reasonably strong , 3) consistent in different geographic areas . Earlier work examining 100-km 2 human-dominated landcover in Ontario, Canada, observed that surveyed avian species richness is a peaked function of pNLC. Objective : We tested whether the same relationship between avian species richness and pNLC is also observed in an independent geographic area that has similar biomes. We also tested whether the peaked relations might be caused by temperature gradients, gradients in the size of species pools, grain size in the analyses, and landscape heterogeneity. Methods : Using breeding bird atlases of Ontario (Canada) and New York State (USA), we estimated species richness in landscapes varying from 25 to 900 km 2 . We related richness to the pNLC in each landscape and examined the same relationships after controlling for temperature, habitat heterogeneity, and species pool size. Results : Landscape-level species richness is a peaked, and not very strong function of pNLC. The relationship is not an artefact of temperature gradients, species pool size, or land cover heterogeneity. Conclusions : The proposition that increased amounts of natural land cover promotes species richness is clearly true at the limit, in landscapes with relatively little (<30%) natural cover. In landscapes with higher amounts of natural cover, a certain amount of human-modified land covers can provide habitat for species that prefer open habitats.

scholarly journals Would conserving natural land cover in landscapes conserve biodiversity?

2018 ◽  
Author(s):  
Rafael X. De Camargo ◽  
David J. Currie
Keyword(s):  
New York ◽  
Species Richness ◽  
Land Cover ◽  
Habitat Loss ◽  
New York State ◽  
Avian Species ◽  
Distribution Data ◽  
Species Loss ◽  
York State ◽  
Natural Land

ABSTRACTIt is generally accepted that protecting natural land cover would protect biodiversity. This would only be true as a general statement if the relationship between richness and natural land cover were monotonic positive and scale- and method-independent. Assertions about habitat loss causing species losses often come from broad-scale assessment of richness (e.g., from range maps) combined with patterns of natural habitat conversion. Yet, the evidence about species loss following habitat loss or fragmentation typically comes from fine-scale experiments. Here, we test whether broad-extent relationships between avian species richness and natural land cover are independent of: 1) whether species distribution data come from systematic censuses (atlases) versus range maps, and 2) the grain size of the analysis. We regressed census-based and range map-based avian species richness against the proportion of natural land cover and temperature. Censused richness at the landscape level was obtained from Breeding Bird Atlases of Ontario and New York State. Range-map richness derived from BirdLife International range maps. Comparisons were made across different spatial grains: 25-km2, 100-km2, and 900-km2. Over regional extents, range-map richness relates strongly to temperature, irrespective of spatial grain. Censused species richness relates to temperature less strongly. Range-map richness is a negative function of the proportion of natural land cover, while realized richness is a peaked function. The two measures of richness are not monotonically related to each other. In conclusion, the data do not indicate that, in practice, landscapes with greater natural land cover in southern Ontario or in New York State have higher species richness. Moreover, different data types can lead to dramatically different relationships between richness and natural land cover. We argue that the argument that habitat loss is the main driver of species loss has become a panchreston. It may be misguiding conservation biology strategies by focusing on a threat that is too general to be usefully predictive.

scholarly journals Landscape‐specific thresholds in the relationship between species richness and natural land cover

2019 ◽  
Vol 56 (4) ◽  
pp. 1019-1029 ◽  
Author(s):  
Jeremy S. Simmonds ◽  
Berndt J. Rensburg ◽  
Ayesha I. T. Tulloch ◽  
Martine Maron
Keyword(s):  
Species Richness ◽  
Land Cover ◽  
Natural Land ◽  
The Relationship

The composition, species richness and species pool size of mono- and oligodominant forest stands of the Western Caucasus

2018 ◽  
pp. 3-18
Author(s):  
V. V. Akatov
Keyword(s):  
Species Richness ◽  
Plant Cover ◽  
Species Abundance ◽  
Pool Size ◽  
Species Pool ◽  
Forest Stands ◽  
Western Caucasus ◽  
Number Of Species ◽  
Dominance Structure ◽  
The Western Caucasus

There is an opinion that the pressure of competition in the plant communities of stable and productive habitats leads to the decrease in evenness of structure of species abundance and species richness up to the monopolization of plots by the most successful competitor (Huston, 1979; Bengtsson et al., 1994). Hence, between the species richness of phytocoenoses and relative density of individuals of dominant species (RDD), negative dependence should be observed. However, according to another view, the number of species and structure of their abundance are determined by the different processes. The number of species is determined by the species pool size and the rate of species immigration, while the abundance structure — by the competition (Stirling, Wilsey, 2001; Ma, 2005; Wilsey, Stirling, 2007). In particular, in some communities a decrease of RDD leads to an increase in abundance of subdominant species and to oligodominant structure. These changes in relative abundance could occur without changes in species richness. Therefore these variables could be weakly related (Ma, 2005; Wilsey, Stirling, 2007; Munson, Lauenroth, 2009). However, it is unclear how widely these scenarios are realized in the plant cover. The aim of our study was to examine the relationship between RDD, the dominance structure as a whole (mono- or oligodominant), the species richness and the size of the species pool in the forest stands of the Western Caucasus.

scholarly journals Roadkill-Data-Based Identification and Ranking of Mammal Habitats

Land ◽  
2021 ◽  
Vol 10 (5) ◽  
pp. 477
Author(s):  
Andrius Kučas ◽  
Linas Balčiauskas
Keyword(s):  
Species Richness ◽  
Land Cover ◽  
Decision Support Techniques ◽  
Mitigation Measures ◽  
Spatial Decision Support ◽  
Vehicle Collisions ◽  
Vehicle Collision ◽  
Ecological Corridor ◽  
As Species ◽  
The Relationship

Wildlife–vehicle collisions, as well as environmental factors that affect collisions and mitigation measures, are usually modelled and analysed in the vicinity of or within roads, while habitat attractiveness to wildlife along with risk to drivers remain mostly underestimated. The main goal of this study was the identification, characterisation, and ranking of mammalian habitats in Lithuania in relation to 2002–2017 roadkill data. We identified habitat patches as areas (varying from 1 to 1488 square kilometres) isolated by neighbouring roads characterised by at least one wildlife–vehicle collision hotspot. We ranked all identified habitats on the basis of land cover, the presence of an ecological corridor, a mammalian pathway, and roadkill hotspot data. A ranking scenario describing both habitat attractiveness to wildlife and the risk to drivers was defined and applied. Ranks for each habitat were calculated using multiple criteria spatial decision support techniques. Multiple regression analyses were used to identify the relationship between habitat ranks, species richness, and land cover classes. Strong relationships were identified and are discussed between the habitat patch ranks in five (out of 28) land cover classes and in eight (out of 28) species (97% of all mammal road kills). We conclude that, along with conventional roadkill hotspot identification, roadkill-based habitat identification and characterisation as well as species richness analysis should be used in road safety infrastructure planning.

scholarly journals Land cover drives large scale productivity-diversity relationships in Irish vascular plants

PeerJ ◽  
2019 ◽  
Vol 7 ◽  
pp. e7035 ◽  
Author(s):  
Hannah J. White ◽  
Willson Gaul ◽  
Dinara Sadykova ◽  
Lupe León-Sánchez ◽  
Paul Caplat ◽  
...  
Keyword(s):  
Species Richness ◽  
Land Cover ◽  
Large Scale ◽  
Vegetation Index ◽  
Scale Effects ◽  
Spatial Scales ◽  
Vascular Plant ◽  
Regional Scale ◽  
The Impact ◽  
The Relationship

The impact of productivity on species diversity is often studied at small spatial scales and without taking additional environmental factors into account. Focusing on small spatial scales removes important regional scale effects, such as the role of land cover heterogeneity. Here, we use a regional spatial scale (10 km square) to establish the relationship between productivity and vascular plant species richness across the island of Ireland that takes into account variation in land cover. We used generalized additive mixed effects models to relate species richness, estimated from biological records, to plant productivity. Productivity was quantified by the satellite-derived enhanced vegetation index. The productivity-diversity relationship was fitted for three land cover types: pasture-dominated, heterogeneous, and non-pasture-dominated landscapes. We find that species richness decreases with increasing productivity, especially at higher productivity levels. This decreasing relationship appears to be driven by pasture-dominated areas. The relationship between species richness and heterogeneity in productivity (both spatial and temporal) varies with land cover. Our results suggest that the impact of pasture on species richness extends beyond field level. The effect of human modified landscapes, therefore, is important to consider when investigating classical ecological relationships, particularly at the wider landscape scale.

Sign in / Sign up

Export Citation Format

Share Document