Deforestation Simplifies Understory Bird Seed-Dispersal Networks in Human-Modified Landscapes

Global biodiversity is threatened by land-use changes through human activities. This is mainly due to the conversion of continuous forests into forest fragments surrounded by anthropogenic matrices. In general, sensitive species are lost while species adapted to disturbances succeed in altered environments. However, whether the interactions performed by the persisting species are also modified, and how it scales up to the network level throughout the landscape are virtually unknown in most tropical hotspots of biodiversity. Here we evaluated how landscape predictors (forest cover, total core area, edge density, inter-patch isolation) and local characteristics (fruit availability, vegetation complexity) affected understory birds seed-dispersal networks in 19 forest fragments along the hyperdiverse but highly depauperate northeast distribution of the Brazilian Atlantic Forest. Also, our sampled sites were distributed in two regions with contrasting land cover changes. We used mist nets to obtain samples of understory bird food contents to identify the plant species consumed and dispersed by them. We estimated network complexity on the basis of the number of interactions, links per species, interaction evenness, and modularity. Our findings showed that the number of interactions increased with the amount of forest cover, and it was significantly lower in the more deforested region. None of the other evaluated parameters were affected by any other landscape or local predictors. We also observed a lack of significant network structure compared to null models, which we attribute to a pervasive impoverishment of bird and plant communities in these highly modified landscapes. Our results demonstrate the importance of forest cover not only to maintain species diversity but also their respective mutualistic relationships, which are the bases for ecosystem functionality, forest regeneration and the provision of ecological services.

Recorded floral and faunal species during tiger census survey in Dudhwa National Park (DNP), Uttar Pradesh

As an attempt of biodiversity conservation, the author documents the floral and faunal species in the Dudhwa National park. Most of the species of the park are identified and enlisted by the author as a part of the tiger census conducted by a dual collaboration of Wildlife Trust of India (WTI) and Wildlife Institute of India (WII). Dudhwa is located in Lakhimpur Kheri district, Uttar Pradesh (UP). The park is divided into seven ranges and four to seven beats as per the records of forest department. Total core area equals 614 sq km, of which 300 sq km is taken as the study area, neglecting the periphery and village close area. Mixed forest (Sal-Jamun) and Phanta (grassland) occupies the survey area.

Landscape Patterns Affect Precipitation Differing across Sub-climatic Regions

Assessment of the impacts of landscape patterns on regional precipitation will help improve ecosystem management and strategies for adaption to global changes. This study aimed to identify the key landscape metrics that affect precipitation across three sub-climatic regions in Inner Mongolia, China, using 266 landscape metrics and daily precipitation data from 38 weather stations for 1995, 2000, 2005, and 2015. Pearson correlation, stepwise linear regression, and Redundancy analysis were used to identify the contributions of landscape patterns to local precipitation in each sub-climatic region. Three-year datasets were used for model development and a one-year data set was used for validation. It was found that the contribution of landscape patterns is higher than that of climatic variations in semi-arid or humid regions. The Core Area Coefficient of Variance (CACoV) of grasslands and Landscape Area (TLA) in non-irrigated croplands have a negative relationship with precipitation in arid regions. Further, the Total Core Area Index (TCAI) of grasslands has a negative correlation with precipitation, while the area proportion (C%LAND) in waters has a significant positive relationship with precipitation in semi-arid regions. Additionally, the Mean Core Area (MCA), Core Area (CA), and Core Area Standard Deviation (CASD) of grasslands and Total Core Area Index (TCAI) of waters are negatively related to precipitation in humid regions. Suitable land use configuration and composition, especially the proportion of grasslands and waters, should be considered in ecosystem management for alleviating the possible harmful effects due to climate change.

Fragmentação florestal na Área de Proteção Ambiental de Tambaba, Paraíba, Brasil

<p>Um dos ecossistemas brasileiros mais fragmentados, devido ao desmatamento histórico, é a Mata Atlântica, que abriga uma das maiores diversidades biológicas do planeta. A área e a forma destes fragmentos podem influenciar o efeito de borda sobre padrões e processos em um ecossistema florestal. O presente estudo mapeou e caracterizou a fragmentação florestal da Área de Proteção Ambiental de Tambaba (APA), no litoral sul da Paraíba, utilizando métricas da paisagem com o objetivo de verificar a efetividade da proteção ambiental na unidade de conservação. Para isto, foi feita uma classificação supervisionada por máxima verossimilhança, da cobertura do solo, a partir de imagens RapidEye em duas classes: (1) floresta (vegetação nativa); (2) não-floresta (todos outros tipos de cobertura). A análise métrica da paisagem (total de fragmentos, área núcleo, proporção de área núcleo por fragmento, entre outros) foi realizada com a extensão Patch Analyst em ambiente ArcGis. Da área total da APA (11.550 ha), 2.200 ha (19%) foram classificados como floresta, distribuídos em 1.364 fragmentos. A área núcleo total variou de 1.470 (efeito de borda de 10 m) a 370 ha (efeito de borda de 50 m), proporcionando uma conservação real entre 13 e 3% da área total. Estes resultados apontam para a necessidade de uma fiscalização intensa e rigorosa do cumprimento das leis, bem como um gerenciamento racional e participativo por meio dos órgãos públicos e do conselho consultivo da APA, para que se protejam os fragmentos remanescentes.</p><p><strong>Palavras chave</strong>: Efeito de borda, conservação, métricas da paisagem, desmatamento.</p><p><strong>Forest fragmentation in the Environmental Protection Area of Tambaba, Paraíba, Brazil</strong></p><p><strong>Abstract</strong>: One of the most fragmented ecosystems in Brazil is the Atlantic Rain Forest, due to centuries of deforestation along the coast which holds one of the world’s greatest biodiversity. Landscape metrics and shape can impact on border effect on patterns and processes of a forested ecosystem. In this paper, we map and characterize the forest fragmentation of the Tambaba Environmental Protection Area (APA), on the coast of Paraíba State, Brazil, using landscape metrics to verify the effectiveness of this protected area. We conducted a land cover classification (supervised classification by maximum likelyhood, RapidEye imagery) into two categories (1) forest and (2) non forest. Landscape metrics (number of fragments, total core area, proportion of core area, among others) were calculated using ArcGis extension Patch Analyst. From the APA’s total 11.550 ha, 2.200 ha were classified as forest (19%), distributed in 1.364 fragments of different sizes. Total core area varied from 1.470 (10 m border effect) to 370 ha (50 m border effect), dependending on edge effect distance, which provides a true conservation of only 13 to 3% of the total APA. These results point to the necessity of an intense and rigorous surveillance of the compliance with laws, as well as a rational and participatory management, through the APA’s management council and public agencies, in order to protect the remnant fragments.</p><p><strong>Key words</strong>: Border effect, conservation, landscape metrics, deforestation.</p>

Landscape fragmentation

The country of Vietnam has long been recognized as an important region for biodiversity (Sterling et al. 2006). High-profile discoveries in the 1990s of many species new to science including large ones such as the Saola (Pseudoryx nghetinhensis), an 85 kg basal member of the cattle subfamily Bovinae and the first new genus of large land-dwelling mammal described since the okapi (Okapia johnstoni) in 1901, have focused the attention of national and international conservation organizations on Vietnam and surrounding countries in mainland Southeast Asia (Hurley et al. in prep.). Conservation action for these endemic, endangered species relies on a clear understanding of trends in habitat conversion. To track deforestation rates through time in Vietnam, Meyfroidt and Lambin (2008) combined remotely sensed data with landscape metrics such as number of patches, mean patch size, mean proximity index, and total core area index. They tested their analyses across a variety of land cover studies including those using Advanced Very High Resolution Radiometer (AVHRR), Landsat, SPOT, and MODIS data sources. They found that forest cover decreased nationally from the 1980s to the 1990s and then showed an increase between 1990 and 2000, due to plantation forests as well as natural forest regeneration. However, the effects of this forest transition on fragmentation metrics noted above differed across the country. For instance, in some places, such as central Vietnam where forest cover is relatively large and well connected, reforestation led to a decrease in forest fragmentation and secondary forests recovered rapidly. However in others, such as areas in the north where forest fragmentation dates back centuries and forests have therefore long been isolated, reforestation did not seem to have an impact on continued fragmentation and habitat loss. In this chapter we detail the importance of fragmentation and landscape metrics to ecology and conservation, outlining when and where remotely sensed data can help in these analyses. We then discuss a subset of fragmentation metrics and point to some challenges in processing fragmentation data. We provide examples of composition and connectivity metrics illuminated with examples from the remote sensing literature.

Indicators of avian nest predation and parental activity in a managed boreal forest: an assessment at two spatial scales

Studies of avian nesting success at the landscape level often use a single indirect measure to evaluate nest predation or parental activity. During two summers at Forêt Montmorency, Quebec, we analyzed and compared three indirect measures of nest predation risk: detection of two nest predators, (1) red squirrel (Tamiasciurus hudsonicus Erxleben) and (2) gray jay (Perisoreus canadensis L.), (3) depredation of bait, and direct observations of parental activity (mostly food transported by adults) at 316 stations over a 230-km2 area. We assessed the relationship between these indicators and three landscape-structure variables (total forested area, total core area, and total edge length) at two spatial scales (83 and 1610 ha). Nest predators were generally present at <30% of stations, <20% of baits were depredated, and >40% of stations exhibited evidence of broods. Bait depredation and the detection of jays or squirrels were correlated, but we found no associations between nest predation and parental activity indicators. Indicators of nest predation and parental activity were not significantly heterogeneous over the study area, despite substantial variation of landscape structure. We argue that parental activity indicators may be more reliable than nest predation indicators, but only as a coarse way to detect variation in nesting success.