Strong influence of trees outside forest in regulating microclimate of intensively modified Afromontane landscapes

Climate change is expected to have detrimental consequences on fragile ecosystems, threatening biodiversity as well as food security of millions of people. Trees are likely to play a central role in mitigating these impacts. The microclimatic conditions below tree canopies usually differ substantially from the ambient macroclimate, as vegetation can buffer temperature changes and variability. Trees cool down their surroundings through several biophysical mechanisms, and the cooling benefits occur also with trees outside forest. The aim of this study was to examine the effect of canopy cover on microclimate in an intensively modified Afromontane landscape in Taita Taveta, Kenya. We studied temperatures recorded by 19 microclimate sensors under different canopy covers, and land surface temperature (LST) estimated by Landsat 8 thermal infrared sensor. We combined the temperature records with high–resolution airborne laser scanning data to untangle the combined effects of topography and canopy cover on microclimate. We developed four multivariate regression models to study the joint impacts of topography and canopy cover on LST. The results showed a negative linear relationship between canopy cover percentage and daytime mean (R2 = 0.65) and maximum (R2 = 0.75) temperatures. Any increase in canopy cover contributed to reducing temperatures. The average difference between 0 % and 100 % canopy cover sites was 5.7 °C in mean temperatures and 10.2 °C in maximum temperatures. Canopy cover reduced LST on average by 0.05 °C/%CC. The influence of canopy cover on microclimate was shown to vary strongly with elevation and ambient temperatures. These results demonstrate that trees have substantial effect on microclimate, but the effect is dependent on macroclimatic conditions, highlighting the importance of maintaining tree cover particularly in warmer conditions. Hence, we demonstrate that trees outside forests can increase climate change resilience in fragmented landscapes, having strong potential for regulating regional and local temperatures.

Importance of Trees Outside Forest (TOF) for immediate earthquake response

A study was carried out in Thulosirubari village of Chautara Sangachowkgadi municipality of Sindhupalchok district, Nepal to analyse the importance of TOF for immediate earthquake response and recovery. More than 80% of the households have trees in their own land with species such as Chilaune (Schima wallichii), Kutmiro (Litsea monopetala), Khote Salla (Pinus roxburghii) and Bamboo are common. Among surveyed households (134), more than 75% respondents reported that they used Schima wallichii for pillar (Khaba) to make temporary houses, whereas bamboo was used for all kind of poles (Dada/Vata/Balo) in more than 80% of temporary houses. Both Bamboo and Schima wallichii were either extracted from their own land or from neighbour's land, i.e. TOF which were easily available and collected as required. We could not draw any statistical conclusion in choice of species to construct temporary houses by wealth categories. However, we have observed that people who have sufficient and varieties of trees in own land, have selected strong and hard wood for permanent house construction whereas those who do not have choice, are limited to use any of the available tree species. People were highly aware about importance of trees to cope with disaster; however selection of species was still debatable because of limited knowledge and researches. J. Biodivers. Conserv. Bioresour. Manag. 2020, 6(1): 9-16